1Forged of high quality stainless steel, this center gauge ruler has high hardness, toughness and durability. 2The ruler body is thickened, and the surface of the ruler is painted with varnish, which can effectively prevent the ruler body from abrasion. 3The scale of the ruler is engraved by a laser, so the reading is clear, and it is not easy to blur the scale after longterm use. 4This high accuracy center angle finder can make 45 line crossing, 90 line crossing, and circular center line crossing. 5It is widely used in hardware processing, cylinder centering, angle marking, disc marking, etc. Item Type: Center Gauge Ruler Material: Stainless Steel Size: Approx. 250 x 160mm/9.8 x 6.3in Applicable Maximum Diameter: Approx. 230mm/9.1in Tolerance: 0.15mm Application: Widely used in hardware machining, cylindrical centering and marking, angle marking, marking discs, etc. 1 x Ruler 1 x Leather Cover