冷切锯：即常温下金属被高速旋转的圆锯片快速切断，切断端面平整，光洁如镜。
Cold cut saw: that is, when the metal is rotated at high speed, the circular saw blade is cut off quickly, and the cutting surface is smooth and smooth.
热切锯：俗称砍锯，也叫摩擦锯。高速切断伴有高温、火花，切断端面呈紫色，多飞边毛刺。
Hot cut saw: commonly known as chopping saw, also called friction saw. High speed cut with high temperature, spark, cut off the end of the purple, multi burr.
锯切方式
Sawing method
冷切锯：高速钢锯片慢旋转，铣断焊管，所以可以做到无毛刺和无噪音。锯切过程产生很少的热量，锯片对钢管有很小的压力，不会造成管壁管口变形。
Cold cut saw: high speed saw blade rotates slowly, milling the welded pipe, so no burr and no noise can be achieved. Sawing process produces very little heat, saw blade has little pressure on the steel tube, and will not cause deformation of the pipe wall.
热切锯：普通电脑飞锯为钨钢锯片高速旋转，接触焊管产生热量使其断开，实为烧断。表面可见高燃痕迹。产生很大的热量，锯片对钢管产生很大的压力，造成管壁管口变形造成质量缺陷 。
Hot sawing: the ordinary computer flying saw rotates at high speed for the tungsten steel saw blade, and the contact pipe generates heat to break it. High burning marks are visible on the surface. A large amount of heat is generated, and the saw blade has great pressure on the steel tube, resulting in deformation of the pipe wall and causing quality defects.