Profile: Webster Instrument, Inc. is a manufacturer of portable metal hardness testing equipment. Our product line includes model B, model B-75 and model BB-75. Our model B-75 tester was developed to obtain more sensitive response to slight changes in the upper range of hardness covered by the model B. This sensitivity is particularly useful in testing mild steel, and the stronger aluminum alloys. For brass, the B-75 covers the range from annealed to full-hard. This added sensitivity is accomplished by incorporating a penetrator of slightly different contour and a heavier load spring than used in the Model B. The 20 graduations on the Webster dial indicator covers the range between 20 and 100 on the Rockwell B scale. Our model BB-75 tester was developed to answer the needs 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 pressure. This combination allows the user to test the soft range of many common materials.