bigHead Weld versus Clinched - which is stronger?

 
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.

Comments

[stainless steel fixings]

A very interesting test with a clear winner in resistance welded fasteners. I guess it comes down to the industrial application and the likely level of tension load to which type of fastener you might choose, but it sounds like the safest option would be to go for resistance welded fasteners.

[welder145]

really informative article. I second the option of playing it safe and going with resistance welds.

http://millermaticmigwelderreviews.com

[S-Bond]

Interesting article. I think using resistance welds is a better choice. I've bookmarked your blog to read more later on.

[Mobile Welding]

I would have also thought welded fastners would be stronger. This post really makes sense. I am going to go post it on twitter so everyone knows.