For Federal Test Method 406, Method 1041, this double cutting test method is intended for use in the determination of the shear strength of plastic materials. However, it is possible to test any material that the device is strong enough to handle. Is used a cylindrical specimen of ½ “in diameter (3/8” and ¼ “diameters being optional). The length of the specimen to be not less than three times the diameter.
The name of the fixture refers to the three plates in contact with the test specimen, that are equal in thickness to the diameter of the specimen being tested. The two outer plates are blocked and invited to a spacer plate which is slightly thicker. Thanks to this conformation the central plate can move freely.

In each end of the fixture  is provided  a hole for attachment to the tensile testing machine. The sheared portion of the specimen completely clears the restrained portions after failure, i.e., a complete shear failure has occurred.  Is reported the failure load and/or the shear strength.

Source of Additional Information:

  • Federal Test Method Standard No. 406, Method 1041, “Shear Strength (Double Shear),” October 1961.