Weld Nut Projection Height Engineering 2

[fgarver]

I need to find any engineering data relating to the height and size of weld projections on weld nuts. Specifically, the relationship between weld projection size/height and torque-off or push-out requirements. The OHIO WELD DATA GUIDE from The Ohio Nut and Bolt Company does not have this information.

 

[TVP]

The best source of information on weld nuts that I have seen is the following standard:

DaimlerChrysler Corporation Process Standard No: PS-1804, WELD NUTS - PROJECTION WELDING

I can probably give you some numbers if you provide some additional details:

What type of nut are you interested in using? hex vs. round, pilot vs. non-pilot, how many projections, etc.

 

[fgarver]

The nut in question is GM #11503319 M8X1.25 Thread. There are three weld projections per nut. Each projection has a radius and each nut has a pilot for hole location.

 

[TVP]

I could not find that particular weld nut in my GM catalog, so I am guessing it is an older part number for the hex-style, type E weld nut. Anyway, the data that I have for push-off strength or torsional strength requirements of a weldnut is given as a function of mating material thickness, not projection height. Obviously one would use the longer projection height when welding into a thicker sheet material. For an M8, the following should be considered minimum requirements:

Push-off strength
metal thickness from 0.76-1.27 mm : 3830 N
1.30-1.85 mm : 5960 N
1.88-2.44 mm : 8010 N
2.46-3.28 mm : 10320 N
> 3.30 mm : 12460 N

Torsional strength : 113 Nm

I hope this helps.

 

[fgarver]

Correction. The nut in question is a M8 X 1.25 thread square nut with four radius projections and a pilot. Using the PS-1804<S> standard from Daimler Chrysler, what is the class, i.e., A, E, EE, F or G? Thanks.

 

[TVP]

I think it is a type A, but I don't know for sure. If you have access to the DCX standard fastener catalog, you can check actual weld nut drawings, which has the type listed at the top.

 

[CoryPad]

fgarver,

Perhaps it is too late for changes, but I would recommend against the square four-projection nut. The main reason is that three points define a plane, so the fourth projection is routinely not touching the mating component, and therefore has a deficient weld. GM does not recommend using those anymore, instead they prefer the round, three-projection weld nuts. For the M8x1.25 size, the GM part numbers are 11517412 (plain) and 11517413 (with thread masking).