ASTM D732-02 pdf free.Standard Test Method for Shear Strength of Plastics by Punch Tool.
1. Push down the punch far enough so that the shoulder clears the specimen proper. The specimen will then be adjacent to the necked-down portion of the punch, and it should be possible to remove the specimen readily from the tool. NoE 2- For thick specimens of some materials the punched-out piece tends to stick in the die. If the test is continued only to the point where maximum load has been developed and stats to fall off rapidly, the specimen may be readily removed from both punch and die.
2. Calculate shear strength in megapascals (or poundsforce per square inch)， determined by dividing the load required to shear the specimen by the area of the sheared edge, which shall be taken as the product of the thickness of the specimen by the circumference of the punch.
3. Report
4. Report the following information:
4.1 Complete identification of the material tested, including type, source, manufacturer’s code mumber, form, principal dimensions, previous history, etc.,
4.2 Method of test, type of test specimen, and dimensions,
4.3 Atmospheric conditions in the test room,
4.4 Conditioning procedure used,
4.5 Diameter of punch,
4.6 Load in newtons (or pounds-force) required to shear each specimen, and the average value, and
4.7 Shear strength in megapascals (or pounds-force per square inch) for each specimen, the average value, and the standard deviation.
5.Two test results obtained within one laboratory shall be judged not equivalent if they differ by more than the r value for that material. The r value is the interval representing the critical difference between two test results for the same material, obtained by the same operator using the same equipment on the same day in the same laboratory.
6. No statement may be made about the bias of this test method, as there is no standard reference material or reference test method that is applicable.ASTM D732 pdf download.