CRIMPING TERMINALS
The importance of using the right tool
INDUSTRIAL SYSTEMS /// CRIMPING TERMINALS: THE IMPORTANCE OF USING THE RIGHT TOOL
Crimping Terminals:
The importance of using the right tool
There are few things in the world of electrical assembly that appear more straightforward than crimping
wires to terminals. Stripped wire is inserted into a short metal tube called a wire barrel. A crimping
tool then compresses the wire barrel tightly around the strands of the stripped wire, forming one
homogeneous metal. No solder, heat, or flux is needed, and the job is done in moments. Its simplicity is
why the solderless terminal remains one of the most popular connectors on the market for more than
seventy years.
Solderless terminals are one of the lowest cost components in a system, but the repercussions of
a bad crimp can be crippling. There is much more complexity to the process than meets the eye.
Unfortunately, many people in the industry overlook the fundamentals of a good crimp and unknowingly
put the integrity of their products at risk. One guiding principle needs to be followed to ensure a good
crimp – tool and terminal must come from the same manufacturer.
Bridging the knowledge gap
Most people think they can use any tool to crimp a terminal.
If after a brief visual inspection, the terminal looks good, they
assume the connection is secure. However, crimping solderless
terminals is a carefully engineered solution, and looks can be
deceiving. A single bad crimp can cause both physical and
electrical problems. If the crimp is not properly formed into
one homogeneous metal, the electrical connection is prone
to high electrical resistance and/or failure. In addition, the
physical connection can be broken when exposed to even
the most minor stresses. Any of these issues will cause the
product to malfunction or fail, resulting in lost production
time, damage, repairs, and potential injury or litigation. See
our Crimp Tooling - Where Form Meets Function publication
on TE.com for a more in-depth look at crimp fundamentals.
Dangers of Improperly Crimped Terminals
From wasted time and scrap to product recalls and possible
litigation, the cost of poor crimp quality can be expensive.
If customers are not using the proper crimp tooling,
(i.e. incorrectly matching the terminal to the crimp tooling)
the end results can produce drastic outcomes.
Severity of an
Improper Crimp
INCORRECT CRIMP HEIGHT ADJUSTMENT
Crimp height too tight:
Flash at under side of crimp, due to over crimping
Crimp height too loose:
Insufficient wire deformation
Good
Crimp
Heat
Poor
Mechanical
Crimp
Poor
Electrical
Crimp
Increased
Scrap
Rework
of Product.
Cost of an Improper Crimp
INDUSTRIAL SYSTEMS /// CRIMPING TERMINALS: THE IMPORTANCE OF USING THE RIGHT TOOL
Possible
Catastrophic
Failures.
Product
Recalls.
Litigation!
Crimping Terminals:
The importance of using the right tool
Optimizing Crimp Performance
ELECTRICAL
PERFORMANCE
Increasing Mechanical
Strength & Electrical
Performance
Tool and terminal are carefully engineered to act in tandem,
creating crimps that optimize electrical and mechanical
performance. A connector engineer configures the crimp
profile (crimp height and crimp width) to achieve the desired
form of the wire and wire barrel when formed into one
homogeneous metal. Too loose a crimp will result in poor
mechanical performance and electrical conductivity. Too tight a
crimp may improve electrical performance up to a point, but can
damage the terminal body or wire strands, causing a reduction
in crimp tensile strength and/or vibration resistance.
Figure 1 illustrates the tradeoffs when designing a crimp. The
shaded grey area is the range of crimp profile configurations
that optimize electrical and mechanical performance. Crimp
design is a meticulous process that takes years of experience
to perfect. Tools and terminals from different manufacturers
are not engineered to work in tandem, and therefore crimp
performance cannot be guaranteed.
MECHANICAL
STRENGTH
CRIMP
DESIGN
RANGE
Decreasing Crimp Height
Figure 1 – Correct Crimp design takes account of
materials, dimensions, and terminal characteristics,
for optimum electrical and mechanical properties
Performance Testing for Industry Certifications
Manufacturers use industry standards developed by safety and certification agencies like UL, CSA, and the United States
Department of Defense (military specifications) to ensure safety and performance of electrical products. Some standards apply
specifically to solderless terminals, while others pertain to the products powered by them. Products are tested in a controlled lab
environment according to a set of detailed instructions and criteria. If the product performs within a strict range of acceptable
outcomes determined by the agency, it becomes certified. Solderless terminals go through a variety of tests to certify their
electrical, mechanical, and physical integrity. Several tests typically required for industry certification are described below.
Vibration Testing
A crimped terminal or splice is mounted between two poles – one pole vibrates and the other remains a stationary support.
The specimen must not show signs of electrical discontinuity, cracking, breaking, loosening of parts, or other physical damage after
typically 18 hours of exposure to intense vibration.
Figure 2 – Military Vibration Test - SOLISTRAND Splices
Figure 3 – Military Vibration Test – PIDG Terminals
PAGE 3
Crimping Terminals:
The importance of using the right tool
Crimp Tensile Strength Testing
A crimped terminal or splice is mounted on a test system by securing
the terminal in a clamping fixture attached to a tensile testing
machine. The system applies a linear pull on the test specimen at
constant applied force until the crimp fails. The wire must not pull out,
break, or separate from the crimp before the minimum crimp tensile
strength requirement is met.
Figure 5 – Crimp Tensile Strength Test Results SOLISTRAND
Tensile (lbs.)
250
200
150
100
50
Figure 4 – Crimp Tensile Strength Test
– Diamond Grip Butt Splice
0
22
18
16
14
12
10
Wire Size
MIL-T-7928 Requirement
Tensile after salt spray exposure
Tensile after vibration testing
Dielectric Strength Testing
This test measures the effectiveness of the insulation of a terminal. A crimped terminal
is dipped in molten insulating wax that covers and seals the exposed end of the
terminal, but not high enough to cover the crimp area. The waxed end of the terminal
is embedded in lead shot, deep enough to cover the crimp area. Voltage is applied
between the loose wire end and the lead shot. The terminal insulation must withstand
the exposure without showing signs of flashover or physical damage.
Figure 6 – Dielectric Strength Test –
PLASTI-GRIP Terminal
Voltage Drop Testing
Voltage drop is defined as the amount of
voltage loss that occurs through all or part
of a circuit. It is an indicator of electrical
resistance and stability of crimped
terminals when exposed to a specified
current. This test measures the level of
homogeneous mass achieved during the
crimping process where the sum of the
two masses’ resistance, the wire barrel and
stripped wire, is less than the total of the
individual components’ resistance. Crimped
terminals are bolted together in a series
chain and exposed to a test current. The
voltage drop must be within a specified
range, based on wire size and test current,
to achieve a passing grade.
Figure 7 – Millivolt Drop Test –
SOLISTRAND
INDUSTRIAL SYSTEMS /// CRIMPING TERMINALS: THE IMPORTANCE OF USING THE RIGHT TOOL
Crimping Terminals:
The importance of using the right tool
The Misinterpretation of Industry
Certifications
Unfortunately, companies that use solderless terminals routinely
misunderstand agency certification criteria, and unknowingly
put their own products at risk. According to the certification
criteria for solderless terminals, all crimps must be created using
tools and terminals from the approved source. If a terminal is not
terminated with the tooling as noted in the associated report, it
is not considered approved since all testing and evaluation of the
terminal by the certification agency was done in conjunction with
the specified tools. From the certification agency’s perspective,
use of different tools could result in different test results.
For example, a UL certified crimp requires a UL certified terminal
and the associated UL certified tool. Military certifications are
divided into two classes. Class 1 terminals and crimp tooling
must conform to the military dimensional and performance
specification. Class 2 terminals and crimp tooling consist of
the terminal manufacturer’s approved application tooling, with
dimensional requirements specified by manufacturer’s drawings,
and the specific terminals that meet the same performance
requirements as Class 1 parts.
When tools are incorrectly matched to terminals, the geometric
relationships between the anvil, terminal, and crimper do not align
correctly. Typically, the wire barrel does not properly form into the
stripped wire, the terminal body twists or bends, and/or the wire
insulation gets damaged. Often invisible to the naked eye, these
defects yield crimp connections of inferior electrical conductivity
and physical integrity.
SOLISTRAND terminals and splices offer
superior performance characteristics
while terminating solid wire, stranded
wire, or irregular shaped conductors.
These brazed-seam uninsulated lugs are
engineered to ensure reliable and longlasting performance in the most punishing
environments. SOLISTRAND is designed
for an estimated 40-year electrical service
life based on millivolt drop testing results.
SOLISTRAND is corrosion resistant,
vibration resistant, and has a tensile
strength that easily meets UL, CSA, and
military specifications when applied with
corresponding approved tooling.
A Crimp for the 21st Century
We are entering a new era called Industry 4.0, where new trends
and innovations like the Industrial Internet of Things (IIoT) and
machine learning combine with advancements in robotics and
automation technology to forever change the way things are
made. Manufacturing processes communicate with each other
and adjust in real time with minimal human input. Machines run
longer, maximize throughput, and produce more efficiently than
ever before. That means component parts must be designed
to keep up. In the 21st century, customers demand rugged,
long-lasting products able to withstand vibration and harsh
environments.
Backed by decades of engineering expertise, TE has a successful
track record of introducing the newest and most innovative
crimp technologies to market, like the DIAMOND GRIP antivibration insulation support sleeve, OCEAN applicator series,
and the TE CrimpData app. TE terminals and splices are proven
to meet the needs of today’s market. Most product meets or
exceeds commercial and/or military certifications. In fact, safety
and certification agencies come to TE for input when developing
new standards for the industry.
PLASTI-GRIP pre-insulated RBY (red,
blue, yellow) terminals and splices are
designed to answer the need for low-cost
insulated electrical terminations. They
consist of a high-conductivity copper body
and PVC insulation. The wire and wire
barrel together form a connection of high
conductivity and tensile strength, while
the tin plating provides good resistance to
corrosion. PLASTI-GRIP is color-coded by
wire size, and corresponds to compatible
tool cavities for easy crimp cavity
identification during crimping. With over
seven billion shipments to date, PLASTIGRIP is the industry standard choice for
all commercial applications and most are
UL and CSA approved when applied with
corresponding approved tooling.
PIDG (Pre-Insulated DIAMOND GRIP)
terminals and splices are designed for
complete and uniform reliability in the
most difficult circuit environments. Proudly
serving customers for 75 years, PIDG has
an added copper sleeve that crimps to
the wire insulation for strain relief support.
This unique design provides maximum
vibration resistance and allows the wire to
bend in any direction without damaging
the wire insulation or conductor, and they
also have an estimated 40-year electrical
service life. PIDG comes in Nylon, PVC,
or Radiation-Resistant insulation options.
PIDG insulation is color-coded by wire
size, and corresponds to compatible tool
cavities for easy crimp cavity identification
during crimping. Most PIDG product is UL,
CSA, and military approved when applied
with corresponding approved tooling.
PAGE 5
Crimping Terminals:
The importance of using the right tool
Save on Applied Costs with TE Tooling
TE’s team of Field Engineering Service Specialists work with customers to provide
expert guidance in creating custom wire crimping solutions that maximize throughput
and optimize Applied Cost. Most manufacturing companies have fewer productive
machine hours than they realize. In many cases it is possible to gain an additional 20
- 60% of productive time each day by selecting the right tooling and making basic
changes in process, training, and/or equipment. The Field Engineering Service team
is available upon request for on-site training, preventative maintenance, hand tool
calibration, and support for TE tooling customers.
DIREC
T
TOTAL
APPLIED
COST
IN
As advancements in automation continue to push throughput levels to an all-time high,
the Total Applied Cost of crimping terminals to wire is fast becoming a critical factor
when designing successful wire crimping solutions for solderless terminals. Total Applied
Cost refers to all costs associated with crimping wires to terminals. It factors-in both the
first-time equipment costs, as well as the long term indirect expenses involved in the
purchase including wire cut and prep, labor, maintenance, rework, and material costs.
Every manufacturing process is unique, so Applied Costs vary drastically based on volume
or throughput needs. Imagine the Applied Cost of trying to crimp thousands of terminals a
day with just one hand tool.
DI
REC
T
20-60%
MORE PRODUCTIVE
Did you know that in many cases it is
possible to gain an additional 20 - 60% of
productivity time each day per installed lead
maker by instituting basic changes in people,
training, processes and/or equipment.
The Power of Automation
TE offers a wide range of tooling options to meet the ergonomic, wire size, and production volume needs of its customers. Its
equipment and services are designed to maximize production uptime, extend tooling life, and minimize manufacturing waste.
Whether production involves a few prototypes in the lab or thousands of leads a day, TE has a tool for every step along the way
to fit evolving production needs. The company’s interchangeable Standard Die Envelope (SDE) allows users to continue using the
same die sets across multiple tooling platforms. All TE die sets feature high quality materials and surface treatments for long lasting
performance. TE applicator dies typically do not show signs of wear until 300,000 cycles or more.
Max. Crimps Per Hour
The following chart is a guide for when
customers should step up to the next tooling
level based on the number of crimps or leads
they are producing per hour.
1200+
600
60
Manual
Hand Tool
90
Power
Assist
Hand Tool
120
Powered
Assist
Bench
3K, 5K, Gll
Terminator
Lead
Maker
TE tools are designed with crimp specification, quality, repeatability, and ease of use in mind. Features like the CERTI-CRIMP
terminal locator and the Crimp Quality Monitoring (CQM) system make it easy to set up and control crimp dimensions, resulting in
repeatable high-quality crimps, giving peace of mind to even unskilled tool operators.
INDUSTRIAL SYSTEMS /// CRIMPING TERMINALS: THE IMPORTANCE OF USING THE RIGHT TOOL
Crimping Terminals:
The importance of using the right tool
Conclusion
Crimping wires to terminals is not a “one size fits all” process; it is a carefully engineered solution – terminal to tooling. In fact,
solderless terminals are designed to perform as specified only when crimped by tools from the same manufacturer. If the tool and
terminal are not from the same manufacturer, the crimp will not meet industry certifications because the quality of the connection
cannot be guaranteed. Defects may not even be visible to the naked eye. Taking the time to select the proper tool and terminal
ensures lasting crimp performance, saving customers time and money. To learn more about our various tool and terminal products,
contact TE today.
Additional Resources
Check out our Crimping Fundamentals video here.
Check out our entire portfolio of Terminals and Splices here.
Visit our Tooling Homepage to find the right tooling solution for you.
Visit our Industrial Terminals and Splices Homepage for product information.
Get Connected
Click the Live Chat button on TE.com to connect with a Product Information Specialist or call the Customer Service numbers below:
•
USA: +1 800 522 6752
•
Japan: +81 44 844 8052
•
Canada: +1 800 522 6752
•
UK: +44 800 267 666
•
Mexico: +51 1 319 7900
•
France: +33 1 3420 86 86
•
Brazil: +55 11 3404 6000
•
Germany: +49 6 151 607 1999
•
China: +86 400 820 6015
•
Italy: +39 011 401 2632
CRIMP
QUALITY
GUIDELINES
CRIMP
QUALITY
GUIDELINES
CRIMP CROSS SECTION CHARACTERISTICS
TOP VIEW
Stripping
Length
CB1 CB2
CH1
CB1
CB1: Conductor crimp width
CB2: Insulation crimp width
CB1
CH2
CH1: Conductor crimp height
CH2: Insulation crimp height
Front Strands
Flush with
Reference
Line
CH1 CH2
CH1
CH1 CH2
Conductor
Present
CH2
OPEN BARREL
SIDE VIEW
CH1: Conductor crimp height
CH2: Insulation crimp height
Good Crimp Quality
Stripping
Length
Incorrect Crimp Quality
WIRE CRIMP
Bellmouth must always
be present
CH1 CH2
CB1: Conductor crimp width
CB2: Insulation crimp width
CB2
CB2
Insulation
Present
Front Strands
Flush with
Reference
Line
CLOSED BARREL
Insulation
Present
WIRE CRIMP
Crimp height too tight
Correct selection of wire, terminal and applicator
Terminal twisted
Conductor
Present
Insulation inside the wire crimp
Bellmouth
permissible
Crimp barrel is closed, legs support each other.
All strands are equally distributed and deformed.
Conductor brush protruding
into terminal body
Terminal damaged
Correct selection of wire, terminal and applicator
Bellmouth on wrong end
Crimp barrel distorted
Cut off tabs present
Locking lances and terminal
body not deformed
INSULATION CRIMP ‘F’
INSULATION CRIMP ‘OVERLAP’
Correct selection of wire, terminal and applicator
For double wire applications with different size wires
always place wire with smallest outer diameter in the bottom
Cut off tab too long
Sufficient gap between legs and bottom of crimp.
All strands are equally distributed and deformed.
INSULATION CRIMP
‘CLOSED BARREL’
Cut off tab deformed
Incorrect applicator adjustment
Asymmetric crimp
Terminal feed
incorrectly adjusted
Unacceptable formation
excessive flash and/or cracks
Anvil and crimper not
aligned or worn
Terminal bend
Incorrect terminal / wire selection
Wire size too large
Crimp barrel
does not close
Wire size too small
Legs too close to bottom of
crimp. Insufficient deformation
of strands, showing voids.
Incorrect applicator adjustment
Crimp height too loose
Crimp height too tight
Insufficient deformation,
showing voids
Flash at underside of
crimp, due to
over crimping
Correct selection of wire, terminal, and crimper
Insulation is securely held. Crimp barrel closed.
INSULATION CRIMP ‘F’
Insulation is securely held. Legs overlap.
INSULATION CRIMP ‘OVERLAP’
Insulation is securely held. No gaps.
Insulation is pierced and could
damage conductor
Insulation material is pierced
INSULATION CRIMP
‘CLOSED BARREL’
Terminal not centered in nest.
Scan to watch our
Crimp Quality Video.
All figures are schematic depictions. In every case, relevant product and application specification take precedence.
To learn more about our tooling solutions please call us at 717-810-2082
or email us at Toolingsales@te.com
Insulation legs are not closed
Insulation is not securely held.
Legs do not overlap.
The above images of crimp failures are only shown as examples and are by no means exhaustive of all possible failures.
In every case, relevant product and application specification take precedence.
To browse our full line up of Terminals and Splices go
to te.com/terminals-splices
tooling.te.com
65780-4 / Revised 09-17 © 2017 TE Connectivity Ltd. family of companies. All Rights Reserved. TE Connectivity, TE connectivity (logo) are trademarks.
PAGE 7
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and/or company names referred to herein might be trademarks of their respective owners.
The information given herein, including drawings, illustrations and schematics which are intended for illustration
purposes only, is believed to be reliable. However, TE Connectivity makes no warranties as to its accuracy or
completeness and disclaims any liability in connection with its use. TE Connectivity‘s obligations shall only be
as set forth in TE Connectivity‘s Standard Terms and Conditions of Sale for this product and in no case will TE
Connectivity be liable for any incidental, indirect or consequential damages arising out of the sale, resale, use
or misuse of the product. Users of TE Connectivity products should make their own evaluation to determine the
suitability of each such product for the specific application.
© 2018 TE Connectivity Ltd. family of companies All Rights Reserved.
1-1773953-1 06/18 Original
INDUSTRIAL SYSTEMS /// CRIMPING TERMINALS: THE IMPORTANCE OF USING THE RIGHT TOOL
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