Monday, 27 February 2012

Spot Welding Test Criteria.

Morning all,

Hope you're all well.

Sorry for the delay since my last update its been manic around here.

As with the laser welding post their is often confusion around spot welding, with heat zones, nuggets, nugget profiles and the test procedure itself.

The industry has chosen BS1140 for it's spot welding standards.

The most common question is about replicating manufactures welds?

Our answer to this is always. The industry has chosen BS1140 and it has set guide lines on heat zones and minium nuggets. If you have taken something off with a 8/10mm nuggets on 0.8/1mm material, replicating this is close to impossible. The reason for this is you have a maxium heat zone on 1mm material of 8mm and to produce a 8/10mm nugget you would have to exceed the maximum heat zone as set by British Standards.

Below is a quick brief outline of the standard and resposibilites. 


TEST CRITERIA




 Welding machine set on manual where possible. Welding clamps may be used.

 1                   Submission of weld tests



If a welder realises that for some reason the weld he has made is likely to fail the subsequent examination and testing, he shall have the option to withhold the test piece and make a second test weld. If the welder does choose to make a second test weld it is the second test piece that shall be examined and tested the first test piece being scrapped.



 2                    Criteria for making 1 mm  spotweld test



·         Indentation not to exceed 20% of each metal thickness = 0.2 mm.

·         Heat distribution  not to exceed 8 mm diameter.

·         Nugget size must be a minimum of 4 mm diameter when tested.

 3                   Criteria  for making 2 mm  spotweld test



·         Indentation is not to exceed 20% of the metal thickness =0.4 mm

·         Heat distribution is not to exceed 12 mm in diameter

·         Nugget size must be a minimum of 5 mm diameter when tested.


 Below is a brief explanation on how spot weld is performed.



As always we welcome your comments and feel free to contact us with any questions or feedback.
Hope you all have a busy week.

Regards

Andy


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