1. 600mm 24 inch inside firm joint caliper with a max open length (capacity) of 275mm/10.8 inch.2. Our metal calipers are forged from 410 stainless steel, with overall heat treatment, micro-magnetic, corrosion-resistant, high hardness, high torque, and good toughness.3. Smooth surface and burr-free, accurate measurement, can be used for a long time and not easy to loosen.4. Inside calipers are used to measure the inner diameter or groove width of the cylindrical hole.5. Firm joint caliper use friction joint to hold the legs not move, adjust a caliper to a scale dimension, one leg of the caliper should be held firmly against one end of the scale and the other leg adjusted to the desired dimension.
