MMC pin size for target fixture

[JoeBlock]

While certifying MMC pins I noticed some differences to what I've always used as a formula to calculate the size of an MMC pin. I learned take the minimum hole size allowed then just subtract the positional tolerance.

Like this: Diameter 4.5 +/-.25 TP 1.50m [-A-][-B-][-C-] would have a pin size 4.5 - .25 = 4.25 - 1.50 = 2.75

Does anyone have more info?

 

[dingy2]

Although the positional tolerances appear a bit heavy, you are correct in your math for the nominal pin size.

Do NOT think that all tool shops know GD & T, they don't. I think I would give them a call on this one.

Dave D.

http://www.qmsi.ca

 

[sunildk]

Yes your math is correct. Your pin size is equal to VC (Virtual Condition).

Sunil