Round Ceiling Light,Circular Ceiling Light,Circular Led Ceiling Light,Round Ceiling Lamp Ningbo Royalux Lighting Co., Ltd. , https://www.royaluxlite.com The thin gauge shown in Figure 1 is a gauge for measuring the aperture through a mast for boring. Since it is open and thin, it is easily deformed when processed. From many failures, we have summed up a set of feasible processing techniques: (1) We use carbon tool steel T8 as the manufacturing material, after forging, roughing, quenching and tempering, hardness is 250~289HB. (2) Semi-finished car, the inner hole is made into φ61mm (our mast diameter is φ60mm), the thickness is 25mm, and the outer diameter is 87_0~(+0.5)mm.