Tristar International

A 20 mm keyless chuck is a drill chuck that can be loosened and tightened quickly without the use of a key. It can be used on the chuck collar of a drill, either by manual operation or when torque is applied. The chuck has a high gripping force in proportion to the torque applied, which prevents the tool's shank from slipping out.

A 13mm keyless chuck is a drill chuck that allows for quick and easy changes to drill bits. It's usually made of metal and is often used on precision drilling machinery that requires close tolerance drilling. 13mm is a common size for drill chucks, and is also known as 1/2 inch.

A 13 mm threaded chuck is a drill chuck that can hold drill bits up to 13 mm in size. It's a self-centering, three-jaw chuck that's usually used on professional equipment and hand and power drills. 13 mm chuck angle drills are typically bigger in size because they can accommodate larger drill bits.