Trib-Tools™ boost the strength of rigging terminals swaged onto rod or wire.

Application Note 17.

Trib-Tools will increase the friction grip of stainless steel terminals swaged onto stainless rod or multi-strand wire in applications like high performance yacht rigging. SS 316 swage fittings are designed to exceed the wire strength when properly assembled under controlled conditions in a dry clean rigging loft. However there is a history of failures with swaged fittings made under less than ideal conditions. These failures may be related to joints made with inferior or dirty materials, worn tools or some other "real world" condition. For a minor cost a Trib-Tool offers sailors comfort with stronger swaged couplings that are easily made under the practical conditions commonly experienced at dockside or when underway if rigging needs to be repaired.

Trib-Tools are used to make Trib-Joints™ which are asperity welded joints that behave like very high friction couplings. A terminal swaged onto a smooth rod or twisted cable like a Dyform or 1 x 19 relies on dry friction to maintain grip. Dry friction is influenced by surface cleanliness, roughness, contact pressure and interfacial metallurgical conditions. Only on more flexible 7 x 7 cables is a mechanical interlock created when swaging. Trib may be slightly less effective on 7 strand cables because high pressure contact surfaces are smaller.

Trib-Tools mildly abrade the surface and release trace amounts of a friction enhancing cold weld agent that is non-corrosive. Once a Trib-Joint is formed it is unaffected by temperature, moisture and is not prone to crevice-corrosion. A swaged joint made after treating the surfaces with a Trib-Tool will typically withstand a 50% higher load than a similar size joint with untreated surface. Trib-Joints also withstand greater overloads without loss of strength due to their ability to absorb large amounts of energy as they momentarily yield. Significantly Trib-Joints do not lose strength like a dry joint does if it yields. The graph below compares the pull off characteristics of similar size joints. Note the Trib-Joint can lose up to 70% of its overlap before the joint strength falls below the yield strength of an untreated joint. In contrast a dry swaged joint loses strength rapidly once its static friction is overcome. The areas under the graphs show the amount of work to disassemble the joints and although the peak strength is only about doubled it typically takes 4 times the work (force x distance) to pull a treated swaged joint apart.

Other applications have been reported that exploit the extra tensile strength. The pull off strength was reported to have doubled on stainless terminals swaged onto twisted stainless cables used to retain a spare wheel on experimental off road vehicles. Generally the precise level of improvement will depend on the materials and design of the terminal, the cable compressibility and the deformation and spring-back of the assembly after swaging.

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for more information email: info8@tribtech.com

The TribTech name derives from "tribos" - Greek for 'rubbing'. 'TribTech' is a trade name used by Ball Burnishing Machine Tools Ltd. of 12 Brookmans Av. Hatfield, Herts. AL9 7QJ. United Kingdom;  Company Reg. No. 1408807, VAT Reg. No. 421 6210 04; a knowledge based company that develops, patents and licenses technology. All rights reserved by Ball Burnishing Machine Tools Ltd. Last modified: May 01, 2008 copyright © 1999/2008. The information and data provided herein should be considered generally representative for the tools and technologies described. In all cases users should carefully evaluate the tools and technologies to determine their suitability for a particular purpose.