ASTM E4-24 Force Calibration and Verification of Testing Machines

ASTM E4 · ASTM standard

ASTM E4 is the ASTM practice for verifying the forces indicated by a testing machine. It confirms that a machine applies and displays load within tolerance so that strength results are traceable and comparable. To schedule a verification or specify a machine that will hold tolerance, talk with our team.

What ASTM E4 Covers

The practice verifies the force-indicating system of tension, compression, and universal testing machines. A force-measuring instrument of known accuracy is loaded on the machine, and the machine is accepted when its indicated force stays within the permitted error, commonly ±1% of the reading, across the verified range.

Why It Matters

Tensile methods such as ASTM E8/E8M assume the machine has a current force verification. Without it, reported yield and tensile strengths cannot be defended in an audit. E4 is the record that ties machine force accuracy to national measurement standards.

Reading the Designation

Cited with a year suffix, such as ASTM E4-24. Confirm the edition before finalizing verification intervals and acceptance criteria.

How the Verification Works

Force is applied at several points spanning the range the machine will be used over. At each point the machine reading is compared with the reference instrument, and the error is calculated. The lowest force at which the machine meets the tolerance sets the bottom of its verified range.

Use a force-measuring instrument calibrated to ASTM E74.
Apply forces through the working range, in the loading mode the machine will be used in.
Record the error at each point and define the verified force range.