The Webster Hardness Testers are a portable, fast, accurate hardness gauge that are made in three distinct models for testing Aluminium, Brass, Copper and Mild Steel. Webster Hardness Testers will quickly identify tempers and test a variety of shapes that other testers cannot check, such as extrusions, tubing and flat stock.
All testers operate in the same manner but differ only in penetrator design, type of load spring and hardness ranges. The principle of operation is simple. The work to be tested is placed between the anvil and the penetrator. Pressure is then applied to the handles until “bottom” is felt at which time the dial indicator is read.
The Model BB-75 Tester was developed to answer the need of certain industries for a method of rapidly testing the hardness of electro-deposited copper in the low hardness range. The B-75 penetrator is used to give sensitivity, and the Model B load spring is employed to give light pressures. This combination allows the user to test the soft range of many common materials.
The graph on the image shows the range covered by the Model BB-75 tester on copper.