27 September 2018
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Fiddling about with separate bolts, washers and nuts adds increased assembly time and cost. One answer has been to produce what is known as a SEMS screw that involves captivating a washer onto a screw or bolt in a one piece design but this is usually an expensive and time consuming process that requires specialist manufacture. The new HEICO-LOCK® Combi-Washer has a unique design that creates your very own SEMS screw at a fraction of the cost and effort.

A traditional SEMS screw is created by placing the washer on the screw before it is thread rolled. Once thread rolled the diameter of the screw is larger than the washer hole and thus ‘captivating’ the washer in place, ensuring that it does not separate from the screw.

The unique design of the Combi-Washer combines an inner locking ring with inset tabs and the proven bolt securing qualities of the company’s HEICO-LOCK® Wedge Lock Washers. The inset tabs of the inner locking ring grip onto the bolt thread, creating a captivated washer. This means that once applied the washer will stay in place on the bolt even when the joint is disassembled for maintenance or repair and initial assembly during production is quicker and easier.

The HEICO-LOCK® Wedge Lock Washers have a combination of radial external teeth and internal wedge shaped cams. As the angle of the internal cams is greater than the pitch of the bolt thread any loosening causes movement in the region of the wedged cams.This creates an expansion in the thickness of the washers which in-turn increases the clamping force.

By integrating the inner locking ring with the bolt securing qualities of the HEICO-LOCK® system your bolt security is assured, at a fraction of the cost and time of producing a bespoke SEMS screw.

The Combi-Washer can be used in conjunction with all commercially available bolts which means you can create your very own SEMS part with your existing bolts. But HEICO don’t stop there as the company offer the service of supplying you with pre-assembled bolts so that you can use it as a SEMS part straight out of the box.

Combining the Combi-Washer and bolt into one versatile fastener creates clear design and manufacturing benefits, not least bottom line savings for production.When using out in the field for onsite maintenance or repair the created SEMS screw is easier to remove and re-install than separate fasteners, particularly where space is tight or conditions demanding.

With easy assembly and permanent connection the HEICO-LOCK® Combi-Washer system offers a flexible, fast and innovative bolted joint solution, particularly for highly loaded bolted connections.

Contact Details:


Tel: 01268 745421

Web: http://www.heico-lock.co.uk/products.html


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