A Portable, Fast, Accurate Hardness Gauge Available in Several Models for Testing Materials such as Aluminum, Brass, Copper and Mild Steel.
The Webster Hardness Tester will quickly identify tempers and test a variety of shapes that other testers cannot check, such as extrusions, tubing, and flat stock.
Webster hardness testers are available in the following three models:
This sectional view shows the basic design principle of the Webster Hardness Tester. The different models vary only in penetrator and load spring design. These combinations give the ability to test a wide range of hardnesses and metal.
The penetrator housing, which contains the penetrator and load spring, slides vertically in the frame of the tester when pressure is applied to the handles. Only sufficient pressure is needed to "bottom" the lower face of the housing against the work. The resistance of the work to the penetrator causes the penetrator to recede into the housing against the spring pressure. The degree of penetration on the test specimen is indicated on the dial indicator sitting on top of the housing assembly. The load can be varied by adjusting the nut above the load spring, permitting the dial reading to be easily corrected against a test block of known hardness.
A penetration of 0.010 inches produces a full-scale reading on the dial indicator. Therefore materials in the softer hardness range should be of sufficient thickness so that the anvil will not influence the test and produce an "anvil effect". In general, soft materials under 0.025 - 0.030 in thickness will not give true readings
The Model B Tester is designed to cover the hardness of aluminum alloys from the 100 to the 7075 series. The 20 graduations on the dial indicator cover the range between 25 and 110 on the Rockwell E Scale.
Developed to obtain a more sensitive response to slight changes in the upper range of hardness covered by the Model B, the Model B-75 Tester is particularly useful in testing the hardness of stronger aluminum alloys as well as of mild steel. The B-75 covers the range from annealed to full-hard for brass. It is accomplished by incorporating a penetrator of slightly different contours and a heavier load spring than used in the Model B, and the 20 graduations on the dial indicator cover the range between 20 and 100 on the Rockwell B Scale.
Certain industries needed a method of rapidly testing the hardness of electrodeposited copper in the low hardness range. The Model BB-75 Tester was the solution. This penetrator is used to give sensitivity while the Model B load spring is employed to give light pressure. This combination allows users to test the soft range of many common materials. The graph below shows the range covered by this tester on copper.