Clearance holes diameter

[APH]

I need to know what the clearance hole size is for screws that is arranged in 3 by 3 matrix. Is there something like this on machinery handbook?

thanks
APH

 

[haggis]

What to you mean by a 3 x 3 matrix? Clearance holes for screws are usualy 1/32" larger than the screw.

 

[APH]

Haggis,

I meant I have 9 screws in 3 rows and 3 colums. I'm afraid that the hole clearance for each screw is not big enough If I use 1/32" x OD of the screw.

Hope this'll be a little more clearer..

Thanks

APH

 

[ivymike]

You mean that you've got a couple of parts that are being screwed together, and you want to make sure that the screws going into holes in part (a) have clearance to pass through holes in part (b), considering tolerances, etc?

 

[MadMango]

Hole clearance is one thing. Positional tolerances between your prime 9 holes and your 9 secondary holes are the issue, coupled with what acceptance/rejection level you are willing to live with during inspection.

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Popular Mechanics, forecasting the relentless march of science, 1949
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[APH]

Ivymike,

You got it. That's what I want. I thought we have something like that in the machinery handbook?

thank
APH

 

[diamondjim]

If you can hold .007 true position
of the holes 1/64 clearance would
be acceptable. If you need .015
true position, then use the 1/32
clearance holes. The smaller holes
create stonger parts but greater
accuracy is needed.

 

[APH]

Diamond,

Would this depend on the size of the screw also?

APH