The Hardness Tester That Fits in Your Pocket. Set of 6 pieces to check the hardness of metals in range of RC40 to RC65. Compact and easy to check the hardness of steel materials which can not be measured by testing machines. Convenient to check the hardness of material before cutting (Milling, Turning, Drilling, etc.) jobs. Convenient to check the hardness during/after heat treatment process. Each of 6 pieces is fitted with distinctive color coded handle and non-slip grip.