Maximum clamping force thread size for aluminium sheet metal

[TMcRally]

I have been looking a chart or similar for choosing a thread size for taping into 5000 grade aluminium sheet. I can find "rule of thumb"type information from 1x to 2x the thread diameter for thread depth but this is not specifically for sheet metal with only one option for thread depth. I'm assuming 2x is for resistance to striping the thread and will not give a maximum clamping force. i.e I expect to find if I have 5mm sheet, an M2.5 will not give me the clamping force of an M4 or M5.

 

[SnTMan]

One source is Machinerys Handbook. It has calculations for thread engagement between dissimialr materials. No doubt there are others. The usual approach is to develop (or exceed) the full strength of the fastener.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand