What is a sems screw? A screw and washer assembly. A screw or bolt which has a captive washer. The washer is frequently loose on the plain shank of the fastener, the shank diameter being equal to the effective diameter of the thread; the thread being rolled from this diameter. The origin of the word is a frequent question. In the 1930’s E. C. Crowther was a representative for a company that sold both shakeproof washers and screws. He came up with the idea of placing the washer on the screw before it was thread rolled. The major diameter of the screw being larger than the washer hole prevents it from coming off. The Illinois Tool Works made machines that produced these patented pre-asSEMbled washers and screws. The s at the end of SEMs is thought to have been subsequently picked up because they are not usually purchased individually. In spite of the original patents and trademarks the word SEMS is generally recognised as a generic term applicable to screw and washer assemblies.
We think you may like our sems screw
SEMS screws combine two separate parts into one pre-assembled, low cost fastener. With washers under the head, SEMS screws are fast, permanent, and easily adaptable to many applications.
SEMs typically come with some form of lockwasher to preventslippage once the screw is firmly secured. Two popular choices include internal-tooth and external-tooth lockwashers. Internal-tooth SEMs have teeth have ring the inside diameter of the lockwasher to bite into the substrate and hold the washer in place, while external-tooth SEMs perform the same task with teeth extending from the outside diameter of the washer.
About us
Yuhuang Electronics Technology Co., Ltd. – Manufacturer, supplier and exporter of screws. Yuhuang offers a wide selection of specialized screws. Whether its indoor or outdoor applications, hardwoods or softwoods. Including machine screw, self tapping screws, captive screw, sealing screws, set screw, thumb screw, sems screw, brass screws, stainless steel screws, security screws and more. Yuhuang is well known for the capabilities to manufacture custom screws. Our highly skilled team will work closely with customers to provide solutions.
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