External Thread Washer Screw Phillips Flange Head Round Tip

External thread washer screw is the screw with an external thread washer under the head. The washer is one kind of lock washer to make the screw anti-loose. Ever Hardware provides custom-made fasteners and customizable packaging.

External thread washer is a washer with serrations that extend radially inward or outward to bite into the bearing surface. This type of washer is especially effective as a lock washer when used with a soft substrate, such as aluminum or plastic, and can resist rotation more than a plain washer on hard surfaces, as the tension between washer and the surface is applied over a much smaller area (the teeth). There are four types: internal, external, combination, and countersunk. The internal style has the serrations along the inner edge of the washer, which makes them more aesthetically pleasing. The external style has the serrations around the outer edge, which provides better holding power, because of the greater circumference. The combination style has serrations about both edges, for maximum holding power. The countersunk style is designed to be used with flat-head screws.

A flange is an external or internal ridge, or rim (lip), for strength, as the flange of an iron beam such as an I-beam or a T-beam; or for attachment to another object, as the flange on the end of a pipe, steam cylinder, etc., or on the lens mount of a camera; or for a flange of a rail car or tram wheel. Thus flanged wheels are wheels with a flange on one side to keep the wheels from running off the rails. The term “flange” is also used for a kind of tool used to form flanges. Pipes with flanges can be assembled and disassembled easily.