Description

This is a black body bolt that has a thread diameter of 5/16″ UNC approx: 7.94mm and is 25mm long. Used to mount screens and similar body parts. The bolt has a built-in lock washer in the skull. It is thus an American coarse threaded bolt that has an outer diameter of 7.94mm, which is then called 5/16. It has 18 threads in one inch = 25.4mm, if you are unsure, you can count the number of threads the screw has in 25.4mm. The length is the total length of the bolt from the washer, it is given in millimeters. The diameter of the tray is 16.5mm

Tip!

Note that you must measure the length of the screw under the skull, you measure the length in millimeters. You should not count on the screw head when measuring the length of the screw.

Check the picture how to measure.

The difference between UNC and UNF is the number of threads per inch.

UNF is fine-threaded with more threads per inch than the coarse-threaded UNC thread.
The smaller sizes are divided from 0 to 12 and are called numerical threads. We call them "Screws"
The larger sizes start with 1/4″ and so on. We call them "Bultar"