Information on the most widely used ASTM standards within the materials testing industry
ASTM D953: Standard Test Method for Pin-Bearing Strength of Plastics
ASTM D953 is a relatively bearing strength standard, this standard actually contains both tensile-mode and compressive-mode loading fixtures, although the latter fixture is seldom used. The standard tensile loading fixture is shown in Figure below.
![]() | ![]() |
The standard specimen is 4.75” long, 0.938” wide, and of a thickness equal to the diameter of the fastener hole used, viz., either 1/8” or 1/4”. Since the fastener hole sizes are different, two different fixtures must be used. A ¼” diameter fastener is more commonly used.
Although originally developed for unreinforced plastics, this test fixture is sometimes used to test composites and other materials also, typically using the ¼” diameter fastener configuration. And the condition specified in ASTM D 953 that the specimen thickness is to be equal to the fastener diameter is often not maintained when testing these other materials. That is, non-conforming tests are often conducted, as for example are reported in Reference 2.
Significance and Use:
This bearing strength test for plastics is intended to apply in the specification of various thermoplastic or thermosetting products in sheet form where rivets, bolts, or similar fastenings are to be used in joining members or sections. It also is intended to apply wherever sheet materials of the classes indicated are required to sustain edgewise loads that are applied by means of pins or rods of circular cross section which pierce the sheet perpendicular to the surface.
The purpose of the test is to determine the bearing strength of the material and to show the bearing stress versus the deformation of the hole. The allowable deformation of the hole in the material should be such as to produce no looseness of joints.
Scope:
This test method covers the determination of the bearing strength of rigid plastics in either sheet form, molded form, or in thermoset pultruded form. Procedure A is applicable for tension loading and Procedure B for compression loading.
Keywords
Bearing Strength - Composite Products - Compression Strength - Compression Test - Compressive Strength - Plastic Film, Sheet And Tapes - Plastic Sheets - Plastics - Tensile Test
![]() |
| Compression type test fixture |
Require More Customized Solutions?