For solid material larger than 2" in diameter, a 2.25" long piece can be used. For all others (tubing, beam, bar <2" RD), an 8" piece will be needed to create our test pieces.
Charpy testing involves creating a test piece with a notch in the center of one side. The test piece will be cooled (where required) to meet the temperature requirement based on a given procedure. The test piece will be placed in a holder and struck with a large hammer that swings as a pendulum. The tester measures how much force was absorbed by the piece before it snapped in half. The broken sample can then be evaluated to determine percent shear and MLE (mils lateral expansion).