What are silk sleeves?

Loosening is a basic skill that locksmiths must master skillfully and is widely used. For example, some screws on the machine tool are cracked or broken, and some screws are not long enough when used. Although thread is a standard part, it is time-consuming and inconvenient to buy on many occasions, so a set of thread is needed. There are three kinds of tapping tools: die and die set. Die can be divided into round die, square die and loose tube die. Die holder is a tool for clamping teeth.

Fitter:

Refers to the manual work in cutting, mechanical assembly and repair operations, which is named because the workpiece is often clamped in a vise on the workbench. The fitter's operations mainly include chiseling, filing, sawing, marking, drilling, reaming, tapping and tapping (see thread processing), scraping, grinding, correcting, bending and riveting. Fiddler is the oldest metalworking technology in mechanical manufacturing. There are five levels of this profession, namely, primary (national vocational qualification level 5), intermediate (national vocational qualification level 4), advanced (national vocational qualification level 3), technician (national vocational qualification level 2) and senior technician (national vocational qualification level 1).