First, the fitter is mainly engaged in manual work such as mechanical cutting, mechanical assembly, mechanical repair, etc., which is named because he often clamps the workpiece with 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.

The fitter's main work:

1. Machining parts: Some machining that is not suitable or cannot be solved by mechanical methods can be done by locksmiths. Such as: scribing in the process of machining parts, precision machining (such as scraping templates, making molds, etc. ), inspection and maintenance, etc.

2. vise assembly: according to the technical requirements of mechanical equipment assembly, the parts are assembled, and after adjustment, inspection and debugging, they become qualified mechanical equipment.

3. Equipment maintenance: When the machinery fails, is damaged or its accuracy is reduced after long-term use, it should also be maintained and repaired by the fitter.

4. Tool manufacturing and repair: manufacturing and repairing various tools, fixtures, measuring tools, molds and various professional equipment.

2. Sheet metal workers pay off, cut and shape various sheets or profiles according to actual needs or drawings, thus forming various required three-dimensional components, such as ventilation pipes in buildings, cyclone dust collectors with big bent heads and small joints in factories, plastic repair of automobile repairs, and various civil white iron products.

Sheet metal workers need profound knowledge of mathematics, geometry, metal welding, cutting, locksmith, riveting and so on.