In the past experience, 12 locksmith has a special skill and application field, which requires a high technical level and practical experience, so the number is relatively small, only a few dozen or so.

As of February 23, 2023, there were no locksmiths of 12 in China. Fitter in China is divided into five grades, namely junior fitter, intermediate fitter, senior fitter, technician and senior technician. Each grade has corresponding evaluation standards and evaluation institutions. For example, junior fitters need to master basic fitter skills and be able to complete simple maintenance and assembly work.