Thumb screws are designed to be tightened and loosened by hand. They come in a variety of head styles, but each includes an easy-grip head which allows for simple "by-hand" installation. The precision thumb screw has finer threads than conventional styles, which allows better control of fastening. The thumb screw head has a knurled surface that gives a good gripping surface, making it easy to tighten or loosen manually. The shoulder provides a good bearing surface and also makes the head easy to grip. The black oxide coating provides some lubricity to the product, meaning that there is less friction generated when using these products. The coating also provides a mild corrosion resistance, but should not be relied on in environments where corrosion resistance is a primary concern. Steel offers strength. A threaded fastener's size name includes information about the major external diameter, followed by the threads per inch, which indicates if it is coarse or fine.
