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GarethW
29th Nov '11, 14:55
I'm designing a part with lots of M3 tapped holes. Basically it's an aluminium block 20mm thick with lots of M3 holes on one face.

What's the minimum pitch between M3 holes? Is there a standard somewhere? I have 2 annoying holes that need to be super-close!

mvalenti
29th Nov '11, 15:41
I think its more of a function of the hardware going into it as well as tool clearances. You dont want to have an assembly where screw heads, nuts, or washers overlap. And the assembler will further curse you if he/she cant get a tool in there. Hope this helps.

GarethW
29th Nov '11, 16:14
I think its more of a function of the hardware going into it as well as tool clearances. You dont want to have an assembly where screw heads, nuts, or washers overlap. And the assembler will further curse you if he/she cant get a tool in there. Hope this helps.

In this case it doesn't matter about the hardware going in to it. Not all holes will be used at the same time. I just need to add all the possible options.

GarethW
2nd Dec '11, 23:00
Supplier came back to me with a recommended pitch of 4.5mm. Seems reasonable to me.

tonycro
3rd Dec '11, 20:54
I would look for 2x the hole diameter as a guide - but I'm normally looking at much bigger holes. so although 4.5mm is encroaching my golden rule an M3 hole is not going to put a massive load on the aluminum block.

so, yes 4.5mm seams reasonable :)


tony

GarethW
3rd Dec '11, 21:12
I would look for 2x the hole diameter as a guide - but I'm normally looking at much bigger holes. so although 4.5mm is encroaching my golden rule an M3 hole is not going to put a massive load on the aluminum block.

so, yes 4.5mm seams reasonable :)



tony

Thanks for the feedback Tony