Cut a section of 45 # steel with the length of 125mm.
Second, sawing:
Installation of saw blade: When installing saw blade, the tightness should be appropriate. Too loose or too tight can easily cause the saw blade to break during sawing. Because the hand saw cuts when it pushes forward and does not cut when it retreats, it is necessary to ensure that the tooth tip direction is forward when installing the saw blade.
Third, for the record:
1. Filing tool: File is the main tool for filing, usually made of carbon tool steels T 12 and T 13, and hardened to HRC62~67 by heat treatment. It consists of file surface, file edge, file tongue, file tail and wooden handle.
2. Types of archives: According to their uses, archives can be divided into three categories: ordinary archives, special archives and plastic archives. Ordinary files can be divided into five types according to their cross-sectional shapes: flat files, square files, round files, semi-circular files and triangular files.
Four, drilling:
The fitter's drilling tool is usually a drilling machine, which is a small bench drill as shown in the figure below.
Five, tapping thread:
1, tap is a special forming tool for machining small-diameter internal threads.
2. The stamping die is a tool for processing external threads, which is made of alloy tool steel 9SiCr and hardened by heat treatment. It looks like a nut, but it drills several chip holes and forms a blade.
3. Tapping internal thread: First chamfer the end hole of the threaded hole to facilitate tapping. Twist it once or twice to check whether the tap is perpendicular to the end face of the hole (visual inspection or square ruler can be used to check in two directions perpendicular to each other), and then continue to screw in the jiaozi rebar with light pressure. When the cutting part of the tap has cut into the workpiece, it can only rotate without pressure, and it should be reversed by 1/4 revolutions per revolution, so as to break the chip.
4. tapping external thread: the method is the same as tapping internal thread.
Assembly of intransitive verbs: