Both clinching and resistance welding are tried and tested fastening technologies used in a myriad of industrial applications. Both methods achieve good results, but which is stronger?
In an effort to answer this question bigHead recently carried out comparative tensile loading tests on clinched fasteners of equivalent material properties and dimensions to that of a bigHead fixing. The results clearly show that resistance welded fasteners can accommodate a 66% higher tensile load than equivalent clinched fasteners. The superior performance equates to an additional 200 Kgf of loading before the product may physically fail. Clinched samples failed above 3.3KN and bigHead samples failed above 5.2KN.
Fig. 1 and 2 below show both clinched and resistance welded fasteners after testing. Both fastener groups have been tested to destruction by the application of a tensile load applied axially to the stud.
The example selected for test was a low carbon steel fixing with a diameter 30mmx1.2mm head and M6x12 centrally affixed stud.
Fig. 1: clinched fasteners after tensile testing
Fig. 2: bigHead fasteners after tensile testing; note that material has remained attached to the stud, having been torn away from the head; the bigHead benchmark test….see below
Tensile loading to destruction is the benchmark test method used by bigHead for each and every production lot. It ensures every fastener they produce is of maximum strength and quality. Contrary to many people’s assumptions a bigHead resistance weld is also the strongest part of the fastener and is actually a point of strength and not of weakness. Indeed, one of bigHead’s pass/fail criterion for the tensile load test carried out on each lot is that the weld does not fail before the steel itself.
