TECHNICAL DATA SHEET
44 Flux-Cored Wire
Activated Rosin Cored Wire for Lead-Free and Leaded Alloys
Product Description
Kester 44 Flux-Cored Wire is an activated rosin formula for use in flux-cored solder wire. 44 has
virtually dominated the field of activated rosin core solders for well over five decades. An
outstanding performance feature of this flux is the “instant- action” wetting behavior. The high
mobility and fast-spreading action of this flux results in more reliable production line soldering.
Under IPC J-STD-004, 44 is classified as ROM1. Despite the increased activity and soldering
performance, 44 passes both 85 °C/85% RH and 40 °C/90% RH SIR test methods.
Performance Characteristics:
High activity RA formulation
Passes both 85 °C/85% RH and 40°C/90% RH IPC SIR testing
Excellent solderability to a wide range of metallizations
Industry standard RA cored wire for decades
Classified as ROM1 per J-STD-004
RoHS Compliance
Kester does not determine any applicable Restriction of Hazardous Substances (RoHS)
exemptions for our lead containing products at the user level. (Applies only if this core flux is
combined with a lead-free alloy.)
Reliability Properties
Copper Mirror Corrosion: Moderate
Tested to J-STD-004, IPC-TM-650, Method 2.3.32
Corrosion Test: Moderate
Tested to J-STD-004, IPC-TM-650, Method 2.6.15
Silver Chromate: Fail
Tested to J-STD-004, IPC-TM-650, Method 2.6.33
Chloride and Bromides: 0.44%
Tested to J-STD-004, IPC-TM-650, Method 2.6.35
44 Flux-Cored Wire
Technical Data Sheet
Issue: 17 May 2021
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TECHNICAL DATA SHEET
Fluorides by Spot Test: Pass
Tested to J-STD-004, IPC-TM-650, Method 2.6.35.1
Surface Insulation Resistance (SIR) 40 °C/90% RH, IPC (typical): Pass
Tested to J-STD-004B, IPC-TM-650, Method 2.6.3.7
Surface Insulation Resistance(SIR), IPC (typical): Pass
Tested to J-STD-004, IPC-TM-650, Method 2.6.3.3
Test Conditions: 85 °C, 85% RH, 7 days, 100V
Blank
9
Day 1
7.46*10 Ω
Day 4
4.9*10 Ω
Day 7
7.7*10 Ω
44
8
2.2*10 Ω
9
2.88*10 Ω
9
9
7.14*10 Ω
9
Availability
44 is available in a wide variety of alloys, wire diameters, flux percentages and roll sizes in both
leaded and lead-free alloys. The most common alloys are Sn63Pb37 and Sn60Pb40. Please
refer to https://www.kester.com for more information.
Note: Core size 50, 58 and 66 = 1.1%, 2.2% and 3.3% flux core, respectively.
Process Considerations
Solder iron tip temperatures are most commonly between 315 to 343 °C (600 to 650 °F) for
leaded alloys and 371 to 400 °C (700 to 750 °F) for lead-free alloys. Heat both the land area
and component lead to be soldered with the iron tip prior to applying the solder wire to land area
or component lead. Do not apply the wire directly to the soldering iron tip; doing so will shorten
the life of the soldering tip.
Additional liquid flux should only be used as a last resort. Any flux applied to the solder location
should be kept to the area of the connection being reworked. If needed, Kester 186 or Kester
NF372-TB may be used as a compatible liquid fluxes to aid in reworking soldered joints. Kester
186 and Kester NF372-TB are also available in Flux-Pens® for optimum board cleanliness.
Cleaning
44 possesses excellent fluxing ability; the flux residues are non-corrosive, non-conductive and
do not require removal for most applications under normal conditions of use. IPA will not clean
the residues off the surface of the circuit board after the soldering process. If removal is
required, a saponifier or cleaning agent specifically designed to clean a no-clean flux is required
to clean the residues. Please contact Kester Technical Support for further information.
44 Flux-Cored Wire
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TECHNICAL DATA SHEET
Recycling Services
We provide safe and efficient recycling services to help companies meet their
environmental and legislative requirements and at the same time, maximize
the value of their waste streams.
Our service collects solder dross, solder scrap, and various forms of solder
paste waste. Please contact your local sales representative for recycling
capabilities in your area or link here.
Storage, Handling and Shelf Life
Storage must be in a dry, non-corrosive environment between 10 to 40 °C (50 to 104 °F). The
surface may lose its shine and appear a dull shade of grey. This is a surface phenomenon and
is not detrimental to product functionality. Flux-cored solder wire has a shelf life determined by
the alloy used in the wire. For alloys containing more than 70% lead, the shelf life is 2 years
from the date of manufacture. Other alloys have a shelf life of 3 years from the date of
manufacture.
Health and Safety
This product, during handling or use, may be hazardous to your health or the environment.
Read the Safety Data Sheet and warning label before using this product. Safety Data Sheets
are available at this link.
Contact Information
To confirm this document is the most recent version, please contact
Assembly@MacDermidAlpha.com
North America
109 Corporate Blvd.
South Plainfield, NJ 07080, USA
1.800.253.7837
Europe
Unit 2, Genesis Business Park
Albert Drive
Woking, Surrey, GU21 5RW, UK
44.01483.758400
Asia Pacific
8/F., Paul Y. Centre
51 Hung To Road
Kwun Tong, Kowloon, Hong Kong
852.3190.3100
Also read carefully warning and safety information on the Safety Data Sheet. This data sheet contains technical information required for safe and economical operation of this product. READ IT THOROUGHLY
PRIOR TO PRODUCT USE. Emergency safety directory assistance: US 1 202 464 2554, Europe + 44 1235 239 670, Asia + 65 3158 1074, Brazil 0800 707 7022 and 0800 172 020, Mexico 01800 002 1400 and (55)
5559 1588
DISCLAIMER: All statements, technical information and recommendations contained herein are based on tests we believe to be reliable, but the accuracy or completeness thereof is not guaranteed. No
statement or recommendation shall constitute a representation unless set forth in an agreement signed by officers of seller and manufacturer. NO WARRANTY OF MERCHANTABILITY, WARRANTY OF FITNESS
FOR A PARTICULAR PURPOSE OR ANY IMPLIED WARRANTY IS MADE. The following warranty is made in lieu of such warranties and all other warranties, express, implied, or statutory. Products are warranted to
be free from defects in material and workmanship at the time sold. The sole obligation of seller and manufacturer under this warranty shall be to replace any noncompliant product at the time sold. Under no
circumstances shall manufacturer or seller be liable for any loss, damage or expense, direct, indirect, incidental or consequential, arising out of the inability to use the product. Notwithstanding the foregoing, if
products are supplied in response to a customer request that specifies operating parameters beyond those stated above, or if products are used under conditions exceeding said parameters, the customer by
acceptance or use thereof assumes all risk of product failure and of all direct, indirect, incidental and consequential damages that may result from use of the products under such conditions, and agrees to
exonerate, indemnify, defend and hold harmless MacDermid, Incorporated and its affiliates therefrom. No suggestion for product use nor anything contained herein shall be construed as a recommendation to
use any product in a manner that infringes any patent or other intellectual property rights, and seller and manufacturer assume no responsibility or liability for any such infringement.
© 2019 MacDermid, Inc. and its group of companies. All rights reserved. “(R)” and “TM” are registered trademarks of MacDermid, Inc. and its group of companies in the United States and/or other countries.
44 Flux-Cored Wire
Technical Data Sheet
Issue: 17 May 2021
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