SCREWDRIVERS
Essential tools for watchmakers, screwdrivers come in different sizes and must always be perfectly adjusted when used so as not to mark the screws or bridges around them. Spare parts often accompany the screwdrivers.
In the vast majority of cases, they are used clockwise for screwing and anti-clockwise for unscrewing. There are some reverse examples where for mechanical reasons the threads are reversed. If this is the case, the reversed screws are normally marked by two additional slots, so three in total.
Screwdriver bits are often made of yellow tempered steel. Thus, they are worked with an india stone and not with a file because they are harder than a file and would damage the file if it were used to sharpen these bits. Also the screwdriver bits must always remain dull to minimize the risk of slipping.