With thread used for industrial use, tensile strength typically refers to the strength and elongation properties of the material. The most important factor to consider when selecting the best industrial thread or yarn for your application is to be sure you are comparing “apples to apples.” When comparing testing data, make sure the materials considered are evaluated using the same tensile strength testing methods.
The resistance of industrial thread and yarns to breaking under tensile stress is one of the most critical and highly-measured properties of materials used in applications such as wire and cable, geotextiles, tarps, web slings and more.
ASTM D2256 is designated as Tensile Properties of Yarns by the Single-Strand Method, which can apply to any industrial yarn. ASTM D7269 is more specific for aramid yarns and is designated as Standard Test Methods for Tensile Testing of Aramid Yarns
The primary difference between ASTM D7269 and ASTM D2256, demonstrated in the video above, is the rate of extension. The ASTM D7269 standard calls for an extension rate of 50 percent of the sample length where the ASTM D2256 standard calls for 12 inches per minute using a 10 inch sample length.
Although these are two different standards, the test results recorded for the two test methods using the same base materials are almost indistinguishable:
- Test one is performed under the conditions of ASTM D7269 with an extension of 5 inches per minute. The breaking strength recorded is 71.61 pounds
- Test two is performed under the conditions of ASTM D2256 with an extension of 12 inches per minute and the breaking strength is 70.84 pounds
The elongation at break for both samples is nearly identical and the breaking strength is also statistically the same.
In addition to these two common tensile testing methods, you may have also heard reference to ASTM D885. ASTM D885 incorporates the same basic testing method as ASTM D2256, but is more written specifically for tire cord and tire cord fabrics.
Do you have questions about ASTM testing for industrial yarn and thread or need assistance determining the best yarn tensile strength for your application? Service Thread’s experienced materials specialists can help you improve the performance of your product.