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Quality Crimp Handbook QUALITY CRIMPING HANDBOOK Order No. 63800-0029 Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 1 of 24 Quality Crimp Handbook Table of Contents SECTION 1 Introduction 2 Purpose 3 Scope 4 Definitions 5 Associated Materials 6 Procedure 7 Measurement 8 Process Control 9 Trouble Shooting 10 Wire Gauge Chart Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 2 of 24 Quality Crimp Handbook SECTION 1 INTRODUCTION TO CRIMP TECHNOLOGY Developed to replace the need to solder terminations, crimping technology provides a high quality connection between a terminal and a wire at a relatively low applied cost. The methods for applying crimp terminations depend on the application and volume, and range from hand-held devices to fully automated systems. The application methods include a basic hand tool, a press and die set, a stripper crimper, or a fully automatic wire processing system. However, no matter what method is used, the setup of each tool is critical for achieving a quality crimp. Today, many OEM companies are using Statistical Process Control (SPC) to continuously improve their crimp terminations. Crimp termination is a complex process and to ensure consistent quality it is necessary to understand the variability and inter-relational interactions that the technology involves. Without a thorough understanding of the crimping process, and all the factors that can affect it, the result may not meet expectations. The three key elements in the crimping process are the terminal, the wire, and the tooling. Terminal For most applications, it is not economically practical for connector manufacturers to design a terminal to accept one wire size, one wire stranding, and one insulation diameter (UL type). Most terminals accommodate many wire sizes, stranding, and a range of insulation diameters, and the terminals are designed to meet acceptable levels over this entire range. Wire The wire stranding and insulation type can vary widely within one wire size. For example, there is more than 18% more material in an 18 AWG by 19-strand wire than an 18 AWG by 16-strand wire. The insulation diameter of an 18 AWG wire can range from 1.78mm (070") to over 4.57mm (180"). Wire strands can be copper, tinned, over coated, or top coated. Wire insulation materials, thickness, and durometers vary from application to application. Tooling What type of tooling does the application require? Does the application require hand stripping of the wire or does the volume dictate an automatic wire-stripping machine? Does the application and volume require hand tools, press and die, or fully automatic wire process machines? Crimping with a manual hand tool, semiautomatic press and die, or fully automatic wire processor, all involve different levels of variability. The terminal, wire, and type of application tooling all affect the quality of the completed terminations. Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 3 of 24 Quality Crimp Handbook SECTION 2 PURPOSE This handbook provides general guidelines and procedures for understanding and achieving acceptable crimp terminations. A glossary in Section 4 lists common terms and definitions. Section 4 lists the tools that are necessary to take accurate measurements and evaluate the crimp's acceptability. The tooling setup is critical in determining the quality of the finished crimp. The attributes that need to be considered include crimp height, conductor brush, bell mouth, and cut-off tab and strip length and insulation position. Variability in one or more of these attributes can reduce the measured pull force. It can be difficult to establish acceptable variability limits because the attributes all interact with one another. For example, a track adjustment for bell mouth also will change the cut-off tab length and the insulation wire position while strip length and wire locations affect the conductor brush and insulation position. Adjusting the insulation crimp height may result in a slight change to the conductor crimp height measurement. It may be necessary for the setup person to make multiple adjustments before establishing an optimal setup. The order the setup is done may help reduce the number of repetitions required for an optimum setup. Section 6 has a flowchart for a process setup while Section 8 is a trouble-shooting guide for common problems. Using Statistical Process Control (SPC) during the crimping process can help minimize the Parts per Million (PPM) reject levels. Section 7 provides a general explanation of the benefits of using SPC. This handbook is structured so that parts, or all, of its contents can be used as a procedural guide for ISO requirements. Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 4 of 24 Quality Crimp Handbook SECTION 3 SCOPE This handbook is intended for Molex customers who are crimping Molex open barrel crimp terminals and are using Molex tooling, primarily in semiautomatic or automatic wire processing termination methods. The handbook's contents may slightly differ from other connector manufacturers' guidelines or individual company procedures. This handbook provides a basic overview of what to look for in an acceptable crimp. It is not intended to replace individual product and/or tooling specifications. Individual terminals or applications may have special requirements. Tooling limitations also may not permit an attribute to be adjusted to meet optimum requirements. Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 5 of 24 Quality Crimp Handbook BEND UP SECTION 4 BRUSH BELL MOUTH CONDUCTOR CRIMP ROLLING SEAM INSULATION CRIMP TWISTING STRIP LENGTH BEND DOWN CUT-OFF TAB TERMINAL CROSS SECTION VIEW EXTRUSIONS CRIMP HEIGHT EXTRUSION EXTRUSION Figure 4-1 DEFINITIONS Anatomy of a Crimp Termination (Figure 4-1)
Bell Mouth (Flare) The flare that is formed on the edge of the conductor crimp acts as a funnel for the wire strands. This funnel reduces the possibility that a sharp edge on the conductor crimp will cut or nick the wire strands. As a general guideline, the conductor bell mouth needs to be approximately 1 to 2 times the thickness of the terminal material. *
Bend Test One way to test the insulation crimp is by bending the wire several times and then evaluating the movement of the insulation and wire strands. As a rule, the insulation crimp should withstand the wire being bent 60 to 90 degrees in any direction, several times. Use care when working with small wire sizes so the wire at the back of the insulation crimp does not shear.
Conductor Brush The conductor brush is made up of the wire strands that extend past the conductor crimp on the contact side of the terminal. This helps ensure that mechanical compression occurs over the full length Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 of the conductor crimp. The conductor brush should not extend into the contact area.
Conductor Crimp This is the metallurgical compression of a terminal around the wire's conductor. This connection creates a common electrical path with low resistance and high current carrying capabilities.
Conductor Crimp Height The conductor crimp height is measured from the top surface of the formed crimp to the bottom radial surface. Do not include the extrusion points in this measurement, (See Figure 4-1). Measuring crimp height is a quick, non-destructive way to help ensure the correct metallurgical compression of a terminal around the wire's conductor and is an excellent attribute for process control. The crimp height specification is typically set as a balance between electrical and mechanical performance over the complete range of wire stranding and coatings, and terminal materials and plating. Although it is possible to optimize a crimp height to individual wire stranding and terminal plating, one crimp height specification is normally created. *Consult individual terminal specification requirements
Cut-off Tab Length This material protrudes outside the insulation crimp after the terminal is separated from the carrier strip. As UNCONTROLLED COPY Page 6 of 24 Quality Crimp Handbook a rule, the cut-off tab is approximately 1.0 to 1.5 times terminal material thickness. * A cut-off tab that is too long may expose a terminal outside the housing or it may fail electrical spacing requirements. In most situations, a tool is setup to provide a cut-off tab that is flush to one material thickness.
Extrusions (Flash) These small flares form on the bottom of the conductor crimp resulting from the clearance between the punch and anvil tooling. If the anvil is worn or the terminal is over-crimped, excessive extrusion is the results. An uneven extrusion may also result if the punch and anvil alignment is not correct, if the feed adjustment is off, or if there is insufficient/excessive terminal drag.
Insulation Crimp (Strain Relief) This is the part of the terminal that provides wire support for insertion into the housing. It also allows the terminal to withstand shock and vibration. The terminal needs to hold the wire as firmly as possible without cutting through to the conductor strands. The acceptability of an insulation crimp is subjective and depends on the application. A bend test is recommended to determine whether the strain relief is acceptable for each particular application. is important to document the insulation crimp height. Then, as part of the setup procedure, the operator can check the crimp height.
Insulation Position This is the location of the insulation in relation to the transition area between the conductor and insulation crimps. Equal amounts of the conductor strands and insulation needs to be visible in the transition area. The insulation position ensures that the insulation is crimped along the full length of the insulation crimp, and that no insulation is crimped under the conductor crimp. The insulation position is set by the wire stop and strip length for bench applications. For automatic wire processing applications, the insulation position is set by the in/out press adjustment.
Strip Length The strip length is determined by measuring the exposed conductor strands after the insulation is removed. The strip length determines the conductor brush length when the insulation position is centered. Figure 4-2
Insulation Crimp Height *Consult individual terminal specification requirements
Process Example Control Chart Thousandths 31.5 Crimp Height Molex does not specify insulation crimp heights because of the wide variety of insulation thickness, material, and hardness. Most terminals are designed to accommodate multiple wire ranges. Within the terminal’s range, the strain relief may not completely surround the wire or fully surround the diameter of the wire. This condition will still provide an acceptable insulation crimp for most applications. Sample 30.5 Contol Limit Control Limit Upper Specification 29.5 Lower Specification 28.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Measurements 1. A large strain relief should firmly grip at least 88% of the wire. 2. A smaller strain relief should firmly grip at least 50% of the wire and firmly hold the top of the wire. To evaluate the insulation crimp section, cut the wire flush with the back of the terminal. Once the optimum setting for the application is determined, it Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 Figure 4-3 The combination of people, equipment, tooling, materials, methods, and procedures needed to produce a crimp termination. Process Control is used to track attributes over time to aid in the detection of change to the process. Detecting a process change when it happens helps prevent many thousands of bad crimps. UNCONTROLLED COPY Page 7 of 24 Quality Crimp Handbook
Pull Force Testing
Shut Height This is the distance (at bottom dead center on a press) from the tooling mounting base plate to the tooling connection point on the ram of the press.
Terminal Position Figure 4-4 PUNCHES Pull force testing is a quick, destructive way to evaluate the mechanical properties of a crimp termination. When making a crimp, enough pressure must be applied to break down the oxides that may build up on the stripped conductor and the tin-plating on the inside of the terminal grip. This is necessary to provide a good metal-to-metal contact. If this does not occur, resistance can increase. Over-crimping a crimp termination will reduce the circular area of the conductor and increase resistance. Pull force testing is also a good indicator of problems in the process. Cut or nicked strands in the stripping operation, lack of bell mouth or conductor brush, or incorrect crimp height or tooling will reduce pull force. Wire properties and stranding, and terminal design (material thickness and serration design), also can increase or decrease pull force levels. WIRE TERMINALS ANVILS Figure 4-6 The terminal position is set by the alignment of the terminal to the forming punch and anvils, and the carrier strip cut-off tooling. The tool set-up determines conductor bell mouth, cut-off tab length, and terminal extrusions PRESS BASE PLATE RAM SHUT HEIGHT GAUGE Figure 4-5 Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 8 of 24 Quality Crimp Handbook
Ruler (Pocket Scale) SECTION 5 ASSOCIATED MATERIALS
Caliper This is used to estimate the five-piece measurement of bell mouth, cut-off tab, conductor brush, wire position, and strip length. The recommended maximum resolution is 0.50mm (.020”). A gauge, consisting of two opposing blades. It used for measuring linear dimensional attributes.
Pull Tester (Reference Figure 5) A device used to determine the mechanical strength of a crimp termination. Most pull testing is done with a device that clamps the wire, pulls at a set speed, and measures force by means of a load cell. A pull tester also can be as simple as hanging fixed weights on the wire for a minimum of one minute.
Eye Loop This is a magnification tool, normally 10 times power or greater, which is used in the aid visual evaluation of a crimp termination.
Toolmaker’s Microscope
Crimp Micrometer This is a micrometer specifically designed to measure crimp height. The measurement is taken in the center of the crimp so the conductor bell mouth does not influence it. It has a thin blade that supports the top of the crimp while a pointed section determines the bottom radial surface. Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 This is used for close visual evaluation and statistical measurement of bell mouth, cut-off tab, conductor brush, wire position and strip length. UNCONTROLLED COPY Page 9 of 24 Quality Crimp Handbook SECTION 6 11. PROCEDURES Tool Setup (Reference Procedures Flow Chart) 1. Check that tooling is clean and not worn. If necessary, clean and replace worn tooling. 2. Disconnect power to the press and remove guarding devices. 3. Install the appropriate tooling into the press. 4. Load terminals into the tooling so that the first terminal is located over the anvil. 5. Manually cycle the press to help ensure a complete cycle can be made without interference. If it cannot, remove tooling and check press shut height. Go to procedure 3. 6. Check that the tooling is aligned. Check the impression on the bottom of the crimp that was made by the anvil tooling. Check that the extrusions and crimp form are centered. If not, align tooling and go to procedure 5. 7. Check that the terminal feed locates the next terminal over the center of the anvil tooling. If not, adjust terminal feed and feed finger and go to procedure 5. 8. Re-install all safety devices that were removed during the set-up. (Follow all safety requirements listed in individual press and/or tooling manuals.) 9. Crimp sample terminals under power. 10. Evaluate cut-off tab length and conductor bell mouth. If adjustment is necessary, disconnect Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. power to the press and remove guarding. Adjust track position. Manually cycle the press and check the feed finger for feed location, go to procedure 7. Evaluate conductor brush. If adjustment is necessary, disconnect power to the press and remove guarding. Adjust wire stop for bench applications or press position on automatic wire processing equipment. Go to procedure 8. Evaluate insulation position. If necessary, adjust strip length, crimp new samples, and go to procedure 11. Loosen insulation crimp height. Crimp sample terminals. Measure conductor crimp height and compare to specification. If necessary, disconnect power and remove guarding. Adjust conductor crimp height, install guards, connect power, and go to procedure 14. Perform a pull force test. Refer to troubleshooting (Section 9) if this test fails. Adjust insulation crimp. Crimp sample terminals. Evaluate insulation crimp. If necessary, disconnect power and remove guarding. Adjust insulation crimp height, install guards, connect power, and go to procedure 18. Measure crimp height and compare to specification. If necessary, disconnect power and remove guarding. Adjust conductor crimp height, install guards, connect power, and go to procedure 18. Document measurements. Please Work Safely At All Times. UNCONTROLLED COPY Page 10 of 24 Quality Crimp Handbook PROCEDURES FLOW CHART Start A Evaluate tooling to ensure it is clean and not worn No Wire processi Replace tooling / clean Ye Disconnect power and remove necessary guards Adjust press position Install tooling into the press Set shut height of the press Load terminals into tooling Remove tooling from the press Adjust terminal feed and/or feed finger Bench Evaluate insulation position Adjust wire stop B A Good Not Good Crimp samples No Adjust conductor crimp height Align tooling Conductor crimp height OK? No No Disconnect power and remove necessary guarding Ye Pull Force test Ye Install safety guarding and connect power Manually cycle the press Crimp samples Adjust track position Not Good Disconnect power and remove necessary guarding Install safety guarding and connect power Pas Adjust insulation Adjust insulation crimp height Crimp samples Not Pas Trouble shooting (See Section 9) Install safety guarding and connect power Disconnect power and remove necessary guarding No Insulation OK? Adjust conductor crimp height Ye End Order No: TM-638000029 Revision: C Adjust strip length Install safety guarding and connect power Terminal feed OK? Terminal centered over anvil? Evaluate cut-off tab and bell mouth Crimp samples Good Loosen insulation crimp Ye No Evaluate conductor brush Good B Ye Tooling aligned? Not Good Disconnect power and remove necessary guards Manually cycle the press Complete cycle? Bench press or wire processing Release Date: 09-04-03 Revision Date: 10-20-09 Ye Conductor crimp OK? No UNCONTROLLED COPY Disconnect power and remove necessary guarding Page 11 of 24 Quality Crimp Handbook bottom wire due to the effects of the terminal serrations. SECTION 7 MEASUREMENT Wire Chart Pull Force Testing 1. Cut wire length approximately 152.00mm (6.00”) long. 2. Strip one end to 13.00mm (.500”), or long enough so no wire insulation is under the insulation grip, or loosen the insulation crimp so it has no grip on the insulation of the wire. 3. Terminate the appropriate terminal to the wire to the nominal crimp height. 4. Visually inspect the termination for bell mouth, wire brush and cut strands. 5. Set pull tester to 25.4.00mm per minute (1.00" per minute). For most applications, a higher rate will not have a significant impact on the data. The slower rate prevents a sudden application of force or jerking that snaps strands. Verify higher pull rates with data taken at 1.00” per minute. 6. If necessary, knot the un-terminated end of the wire (If insulation slips on wire). 7. Regardless of pull tester type, both wire and terminated end must be securely clamped. (Note: Clamp terminal contact interface, do not clamp conductor crimp) 8. Activate pull test. 9. Record pull force readings. A minimum of five pull force measurements should be done to confirm each set-up. A minimum of 25 readings should be taken for capability. 10. Compare lowest reading to minimum pull force specification. Note: High variability and lower CpK's are common for double wire applications. The variability is due to more variation in conductor brush, conductor bell mouth and fewer strands of one wire being in contact with the serrations on the terminal barrel. A double crimp application is considered no better than the smallest wire crimped. Higher pull force readings can be seen if both wires are gripped and pulled exactly together. Pulling each wire individually will result in a much lower pull force reading. If both wires are of the same size, the top wire will normally result in a lower reading than the Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 Note: Pull force has only a minimum specification. For CpK calculations, the average reading is assumed nominal and the upper specification limit is set so CP and CpK are equal. High pull force readings that increase the standard deviation can lower CpK even if the mean and lowest reading are increased. Test Values for Pull Force Test UL486A Size of Conductor Pullout Force* AWG mm2 Lb. N 30 0.05 1.5 6.7 28 0.08 2 8.9 26 0.13 3 13.4 24 0.20 5 22.3 22 0.324 8 35.6 20 0.519 13 57.9 18 0.823 20 89.0 16 1.31 30 133.5 14 2.08 50 222.6 12 3.31 70 311.5 10 5.261 80 356.0 8 8.367 90 400.5 *Consult individual specifications Crimp Height Testing 1. Complete tool set-up procedure. 2. Crimp a minimum of five samples. 3. Place the flat blade of the crimp micrometer across the center of the dual radii of the conductor crimp. Do not take the measurement near the conductor bell mouth. 4. Rotate the micrometer dial until the point contacts the bottom radial surface. If using a caliper, be certain not to measure the extrusion points of the crimp. 5. Record crimp height readings. A minimum of five crimp height readings is necessary to confirm each set-up. A minimum of 25 readings is necessary to determine capability. 6. Check crimp height every 250 to 500 parts throughout the run. UNCONTROLLED COPY Page 12 of 24 Quality Crimp Handbook Note: Crimp height is usually control charted because it is a quick, nondestructive measurement and is critical for the termination's electrical and mechanical reliability. There are three primary purposes for control charting. One, the number of setup samples is normally small, and its statistical value is limited. Two, since special cause/effects on a process are irregular and unpredictable; it is necessary to have a means of catching changes in the process as soon as they occur. This prevents having to scrap thousands of terminations after the run is over. Three and this is most important, the data is necessary to assess and improve the crimp process. Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 13 of 24 Quality Crimping Handbook Figure 7-1 PULL TESTING Figure 7-2 CRIMP MICROMETER Order No 63800-0029 Revision: A Release Date: 09-04-03 Revision Date: 09-04-03 Figure 7-3 CALIPER UNCONTROLLED COPY Page 14 of 24 Quality Crimp Handbook SECTION 8 CRIMP PROCESS CONTROL The crimp process is the interaction of a terminal, wire, tooling, personnel, methods and procedures, and environmental attributes. When this process is controlled, it will produce a quality termination. Quality control is an important part of quality crimping. It should not take excessive setup or inspection time to do, and it can save a harness manufacturer thousands of dollars in potential rework or re-manufacturing. Variability is the slight change that occurs from crimp to crimp. There are two types of variability, common or special. Common causes of variation affect the process uniformly and are the result of many small sources. Common variability is inherent tolerances within a reel of wire or terminals. Common variability also is created by the natural tolerances of the stripping and crimping machines. Reducing variability at the common level typically has to come from changes to the wire, terminal, and tooling manufacturer. Special causes of variation occur irregularly and unpredictably. Without checks throughout a run, having a tool become loose after the first hundred crimps or a jam resulting from a damaged tool may be undetected until thousands of crimps are made. Process Capability Before putting a new crimping tool in production, Molex recommends that each customer do a capability study, using the specific wire that will be used in its process. A capability study, which is based on the assumption of a normal distribution (bell-type curve), estimates the probability of a measurement being outside of specification. CpK 0.67 1 1.33 1.67 2 Capability +/- Sigma % Yield 2 95.45 3 99.73 4 99.99 5 99.99+ 6 99.99++ PPM* 45,500 2,699 63 0.57 0 * PPM - Parts per million potential defects. Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 A 25 piece minimum sample needs to be taken from the crimping process. Calculate the average and standard deviation for each specification. A capability index is defined by the formula below. Cp may range in value from zero to infinity, with a larger value indicating a more capable process. A value greater than 1.33 is considered acceptable for most applications. Cp is calculated with the following formula. ___Tolerance___ 6*Standard Deviation The CpK index indicates whether the process will produce units within the tolerance limits. CpK has a value equal to Cp if the process is centered on the mean of specification; if CpK is negative, the process mean is outside the specification limits; if CpK is between 0 and 1 then some of the 6 sigma spread falls outside the tolerance limits. If CpK is larger than one, the 6-sigma spread is completely within the tolerance limits. CpK is calculated with the lesser of the following formulas: __(USL - Mean)__ 3*Standard Deviation __ (Mean - LSL)__ 3*Standard Deviation USL = Upper Specification Limit, LSL = Lower Specification Limit Six sigma is a goal of many companies because it represents virtually zero defects. The ability of a company to achieve a six-sigma level depends on the amount of common variability in its process. For example, hand stripping the wire produces more variability than a stripping machine; crimping hand tools produce more variability than a press and die set, and bench terminations produce more variability than a wire-processing machine. A part of the variability in crimping will result from the type of instruments that are used to measure the parts and the operator's ability to repeat the measurement. A crimp micrometer will measure more accurately than a dial caliper. An automatic pull force system will measure better than a hook type scale. It is important that the measurement gauge has enough resolution. Two operators may measure the same part differently, or the same operator may measure the part differently UNCONTROLLED COPY Page 15 of 24 Quality Crimp Handbook when using two types of gauges. Molex recommends a gauge capability study to identify what part of the variability is coming from measurement error. Microterminals crimped to small wire sizes need a tight crimp height range to maintain pull force. The variability from measurement error can keep CpKs low. The capability of the crimping tools needs to be reconfirmed if the production data is significantly different from the capability study. on the chart before making a crimp height adjustment. If data is recorded after each adjustment, the process is likely to assume control and provide little data for improving the process. The operator needs to make as many notes as possible on the chart. The only truly effective and economically sensible way to manage a manufacturing process is to understand, monitor and reduce sources of variability that are inherent to the process itself. Every minute required for setup or adjustments is unproductive. Production What does this sample chart tell us? Before the tool is ready for production, the level of capability needs to be established. Many harness manufacturers run only a few hundred or few thousand wires at one time. In this case, it is not practical or economical to run a twenty-five-piece capability with every set-up. Visual Inspection It needs to be standard operating procedure for the operator to manually fan each bundle of crimped wires and visually check bell mouth, conductor brush, insulation position, cut-off tab length, and insulation crimp. Control Charting Crimp height is typically control charted because it is a quick nondestructive measurement and is critical for the termination's electrical and mechanical reliability. There are three primary purposes for control charting. One, the number of setup samples is usually small, with limited statistical value. Two, since special cause effects on a process are irregular and unpredictable; it is necessary to be able to catch changes in the process as soon as they occur. This prevents thousands of terminations from being scrapped after the run is over. Three, and most important, this data is necessary to assess and improve the crimp process. Once the tooling process is setup and the wire size does not change, keep one control chart for wire color changes, wire length changes, terminal material changes, or setup adjustments. Record the data point Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 X and R Chart Control limit for sample of 5 = Avg (Avg of 5readings) + .577 x Avg (Ranges) It indicates that a process shift occurred between measurement 12 and 13. This type of shift could occur due to a change in wire, a change in terminal lots, a jam in the machine that damaged the tooling, a change in operators, or an adjustment to the insulation crimp. Since the measurements are still within specification, would you stop production to adjust crimp height? A shift in the process due to a change in material may warrant a crimp height adjustment. A shift after a jam would not indicate an adjustment, but a close evaluation of the tooling. A shift in the process between operators would not indicate an adjustment, but an evaluation of measurement capability. The purpose of a control chart is to identify what caused the shift in process to determine if an adjustment to the process is needed. UNCONTROLLED COPY Page 16 of 24 Quality Crimp Handbook SECTION 9 TROUBLE SHOOTING Wire Preparation Symptom Irregular insulation cut (Figure 9-1) Cut or nicked strands (Figure 9-2) Irregular conductor cut-pulled strands (Figure 9-3) Wire length variability too high (Figure 9-4) Wrong strip length (Figure 9-4) Cause Worn tooling Wire cut depth too shallow Damaged tooling Cut depth too deep Conductor not on wire center Worn tooling Wire cut depth too shallow Wire drive rollers/belts worn Insulation durometer too hard Wire straightener too loose or tight Incorrect setup Figure 9-1 IRREGULAR INSULATION CUT Figure 9-3 PULLED STRANDS Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 Solution Replace tooling Adjust cut depth Replace tooling Adjust cut depth Contact wire supplier Replace tooling Adjust cut depth Replace belts/rollers Increase drive pressure Adjust wire straightener Re-setup tooling Figure 9-2 CUT STRANDS Figure 9-4 WIRE LENGTH VARIABILITY OR WRONG STRIP LENGTH UNCONTROLLED COPY Page 17 of 24 Quality Crimp Handbook Bell Mouth and Cut-off Tab Length Symptom Low pull force (Figure 9-6 and 9-7) Cut or nicked strands (Figure 9-8) Long cut-off tab (Figure 9-9) Figure 9-5 OPTIMAL CRIMP Cause Excessive bell mouth, no cut-off tab Excessive bell mouth, cut-off tab alright No bell mouth and/or excessive cut-off tab Good bell mouth and excessive cut-off tab Figure 9-6 EXCESSIVE BELL MOUTH Figure 9-8 NO BELL MOUTH EXCESSIVE CUT-OFF TAB Order No: TM-638000029 Revision: C Solution Adjust track position for small cut-off tab Check for worn or incorrect punch tooling and replace Adjust track position Check for camber in terminal strip Check for worn cut-off and replace if necessary Check for worn punch tooling, replace, and re-adjust track Release Date: 09-04-03 Revision Date: 10-20-09 Figure 9-7 EXCESSIVE BELL MOUTH NO CUT-OFF TAB Figure 9-9 EXCESSIVE CUT-OFF TAB GOOD BELL MOUTH UNCONTROLLED COPY Page 18 of 24 Quality Crimp Handbook Conductor Brush and Insulation Position Symptom Insulation under conductor crimp, good conductor brush (Figure 9-10) Insulation under conductor crimp, long conductor brush length (Figure 9-11) Cause Solution Strip length too short Check specification, adjust strip length longer Bench - Wire stop position incorrect Wire Processing – Press position incorrect Adjust wire stop to center of transition area Adjust press position away from wire Check specification, adjust strip length longer Re-adjust wire stop position for bench applications OR re-adjust press position for wire processing applications Check specification, adjust strip length shorter Re-adjust wire stop position for bench applications OR re-adjust press position for wire processing applications Insulation under conductor crimp, short or no conductor brush (Figure 9-12) Insulation edge centered in transition area, conductor brush too long (Figure 9-13) Strip length too short Strip length too long Irregular wire cut-off or strands pulled from insulation bundle Insulation edge centered in transition area, conductor brush too short (Figure 9-14) Strip length too short Insulation edge under insulation crimp, good or long conductor brush (Figure 9-15) Strip length too long Insulation edge under insulation crimp, short or no conductor brush (Figure 9-16) Bench - Wire stop position incorrect Wire processing - Press position incorrect Verify operators wire placement ability Figure 9-10 INSULATION UNDER CONDUCTOR CRIMP, GOOD CONDUCTOR BRUSH Figure 9-12 INSULATION UNDER CONDUCTOR CRIMP, SHORT OR NO CONDUCTOR BRUSH Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 Check specification, adjust strip length longer Re-adjust wire stop position for bench applications OR re-adjust press position for wire processing applications Check specification, adjust strip length shorter Re-adjust wire stop position for bench applications OR re-adjust press position for wire processing applications Adjust wire stop to center of transition area Adjust press position away from wire Operate training, reduce crimping rate Figure 9-11 INSULATION UNDER CONDUCTOR CRIMP, CONDUCTOR BRUSH TOO LONG Figure 9-13 CONDUCTOR BRUSH TOO LONG Figure 9-15 INSULATION UNDER INSULATION CRIMP, CONDUCTOR BRUSH TOO LONG Check for worn stripping tooling Figure 9-14 CONDUCTOR BRUSH TOO SHORT Figure 9-16 INSULATION UNDER INSULATION CRIMP, CONDUCTOR BRUSH TOO SHORT UNCONTROLLED COPY Page 19 of 24 Quality Crimp Handbook Insulation Crimp Symptom Cause Solution Terminal surrounds less than 88% of a large diameter wire (Figure 9-21) Terminal contacts less than 50% of a small diameter wire (Figure 9-22) Insulation crimp barrels cut through insulation into conductor strands (Figure 9-23) Insulation not firmly gripping insulation, fails bend test (Figure 9-24) Crimp too loose, not enough terminal insulation barrel Tighten insulation crimp height Evaluate terminal Too much terminal insulation barrel Evaluate terminal Crimp too tight Adjust insulation crimp height* Crimp too loose Adjust insulation crimp height tighter * Inexpensive hand tools provide no adjustment for the insulation crimp. A hand tool is intended for low volume applications. Although you are not able to adjust the insulation crimp on a hand tool, an insulation crimp, which pierces the insulation, may still be considered acceptable for many applications. This criterion only applies to hand tools due to their low speed crimp cycle. If the insulation crimp pierces the insulation, the wire strands tend to move aside without damage. Figure 9-17 PREFFERRED INSULATION CRIMP Figure 9-18 PREFFERRED INSULATION CRIMP Figure 9-20 ACCEPTABLE INSULATION CRIMP Figure 9-22 MARGINAL INSULATION CRIMP Order No: TM-638000029 Revision: C Figure 9-21 MARGINAL INSULATION CRIMP Figure 9-23 MARGINAL INSULATION CRIMP Release Date: 09-04-03 Revision Date: 10-20-09 Figure 9-19 ACCEPTABLE INSULATION CRIMP Figure 9-24 MARGINAL INSULATION CRIMP UNCONTROLLED COPY Page 20 of 24 Quality Crimp Handbook Crimp Height Symptom Crimp height off target (Figure 9-26) Crimp height variability too high (Figure 9-27) Cause Changed wire type vendor or stranding Changed insulation color or durometer Changed crimp tooling Changed crimp press (shut height) Changed press type (manufacturer) Changed terminal reel (lot code) Changed tooling set-up Damaged or worn tooling Wire variability Terminal variability Damaged, loose or worn tooling Measurement error Terminal spring-back too great, over crimping Cut or missing wire strands Solution Adjust tooling back to target Inspect incoming product Tooling replacement or tightening Gauge capability analysis Crimp height adjustment Stripping process adjustment Figure 9-25 OPTIMAL CRIMP HEIGHT CHART Figure 9-26 CRIMP HEIGHT OFF TARGET Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 Figure 9-27 CRIMP HEIGHT VARIABILITY TOO HIGH UNCONTROLLED COPY Page 21 of 24 Quality Crimp Handbook Pull Force Symptom Wire breaks before conductor crimp - low pull force (Figure 9-29) Wire pulls out of conductor grip - low pull force (Figure 9-29) Cause Cut or nicked strands Crimp height too low Small or no bell mouth Insulation crimp through insulation wall Crimp height too high Small or no conductor brush Conductor bell mouth too big Gold terminal application Terminal material thickness too small Light serrations on terminal Solution Check the stripping process Adjust crimp height Adjust tooling track Raise insulation crimp height Adjust crimp height Increase strip length Adjust tooling track Evaluate the terminal application Contact your local sales engineer Figure 9-28 OPTIMAL PULL FORCE CHART Figure 9-29 LOW PULL FORCE CHART Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 22 of 24 Quality Crimp Handbook SECTION 10 Wire Gauge Chart AWG 8 8 8 8 8 8 10 10 10 10 12 12 12 12 12 14 14 14 14 14 16 16 16 16 16 16 18 18 18 18 18 18 20 20 20 20 20 20 22 22 Wire Area Sq. mm Sq. inch 8.302 .01287 7.820 .01212 7.955 .01233 8.605 .01334 8.513 .01319 8.424 .01306 5.261 .00816 4.740 .00735 5.006 .00776 5.320 .00825 3.308 .00513 3.632 .00563 3.085 .00478 3.294 .00511 3.3118 .00514 2.082 .00323 2.270 .00352 1.941 .00301 2.078 .00322 2.112 .00327 1.308 .00203 1.433 .00222 1.229 .00191 1.317 .00204 1.307 .00203 1.330 .00206 .823 .00128 .897 .00139 .811 .00126 .963 .00149 .825 .00128 .823 .00128 .519 .00080 .563 .00087 .507 .00079 .616 .00096 .523 .00081 .519 .00081 .324 .00050 .355 .00055 Order No: TM-638000029 Revision: C Stranding No. Dia. 1 .1280 19 .0285 49 .0179 133 .0113 168 .0100 665 .0020 1 .1019 37 .0159 49 .0142 105 .0100 1 .080 7 .0320 19 .0179 65 .0100 165 .0063 1 .0641 7 .0253 19 .0142 41 .0100 105 .0063 1 .0508 7 .0201 19 .0113 26 .0100 65 .0063 105 .0050 1 .0403 7 .0159 16 .0100 19 .0100 41 .0063 65 .0050 1 .0320 7 .0126 10 .0100 19 .0080 26 .0063 41 .0050 1 .0253 7 .0100 Release Date: 09-04-03 Revision Date: 10-20-09 Wire Diameter mm In. 3.25 .128 3.68 .145 3.73 .147 3.73 .147 3.73 .147 3.73 .147 2.59 .102 2.92 .115 2.95 .116 2.95 .116 2.05 .081 2.44 .096 2.36 .093 2.41 .095 2.41 .095 1.63 .064 1.85 .073 1.85 .073 1.85 .073 1.85 .073 1.30 .051 1.52 .060 1.47 .058 1.50 .059 1.50 .059 1.47 .058 1.02 .040 1.22 .048 1.19 .047 1.24 .049 1.19 .047 1.19 .047 .81 .032 .97 .038 .89 .035 .94 .037 .91 .036 .91 .036 .64 .025 .76 .030 Circular Mills 16384 15433 15700 16983 16800 16625 10384 9354 9880 10500 6529 7168 6088 6500 6549 4109 4481 3831 4100 4167 2581 2828 2426 2600 2580 2625 1624 1770 1600 1900 1627 1625 1024 1111 1000 1216 1032 1025 640 700 UNCONTROLLED COPY Wire Break N Lbs. 2175.00 489.0 2048.72 460.6 2084.21 468.6 2254.49 506.9 2230.22 501.4 2206.99 496.2 1378.44 309.9 1241.75 279.2 1311.63 294.9 1393.89 313.4 866.69 194.8 951.56 213.9 808.16 181.7 862.88 194.0 869.37 195.5 545.45 122.6 594.81 133.7 508.59 114.3 544.28 122.4 553.24 124.4 342.58 77.0 375.43 84.4 322.07 72.4 345.15 77.6 342.48 77.0 348.47 78.3 215.60 48.5 234.93 52.8 212.40 47.8 252.23 56.7 216.03 48.6 215.72 48.5 135.94 30.6 147.53 33.2 132.75 29.8 161.43 36.3 136.99 30.8 136.07 30.6 84.97 19.1 92.93 20.9 Page 23 of 24 Quality Crimp Handbook AWG 22 22 24 24 24 24 24 26 26 26 26 28 28 28 30 30 30 32 32 32 Wire Area Sq. mm Sq. inch .382 .00059 .329 .00051 .205 .00032 .227 .00035 .201 .00031 .241 .00037 .200 .00031 .128 .00020 .141 .00022 .127 .00020 .154 .00024 .080 .00012 .089 .00014 .093 .00014 .051 .00008 .057 .00009 .060 .00009 .032 .00005 .034 .00005 .039 .00006 Americas Headquarters Lisle, Illinois 60532 U.S.A. 1-800-78MOLEX amerinfo@molex.com Stranding No. Dia. 19 .0063 26 .0050 1 .0201 7 .0080 10 .0063 19 .0050 41 .0031 1 .0159 7 .0063 10 .0050 19 .0040 1 .0126 7 .0050 19 .0031 1 .0100 7 .0040 19 .0025 1 .0080 7 .0031 19 .0020 Far East North Headquarters Yamato, Kanagawa, Japan 81-462-65-2324 feninfo@molex.com Wire Diameter mm In. .79 .031 .76 .030 .61 .024 .58 .023 .61 .024 .58 .023 .58 .023 .40 .016 .53 .021 .51 .020 .48 .019 .32 .013 .38 .015 .41 .016 .25 .010 .30 .012 .30 .012 .20 .008 .20 .008 .23 .009 Far East South Headquarters Jurong, Singapore 65-6-268-6868 fesinfo@molex.com Circular Mills 754 650 404 448 397 475 394 253 278 250 304 159 175 183 100 112 118 64 67 76 Wire Break N Lbs. 100.11 22.5 86.29 19.4 53.63 12.1 59.47 13.4 52.69 11.8 63.06 14.2 52.31 11.8 33.56 7.5 36.88 8.3 33.19 7.5 40.36 9.1 21.08 4.7 23.23 5.2 24.24 5.4 13.28 3.0 14.87 3.3 15.64 3.5 8.50 1.9 8.93 2.0 10.09 2.3 European Headquarters Munich, Germany 49-89-413092-0 eurinfo@molex.com Corporate Headquarters 2222 Wellington Ct. Lisle, IL 60532 U.S.A. 630-969-4550 Fax: 630-969-1352 Visit our Web site at http://www.molex.com Order No: TM-638000029 Revision: C Release Date: 09-04-03 Revision Date: 10-20-09 UNCONTROLLED COPY Page 24 of 24