What should the hole tolerance for a .375 DIA. dowel pin be in order to be a slip-fit? 1

[MrFrench24]

Hi,

I have an alloy steel dowel pin of .375 DIA. that I am inserting into an aluminum housing. Can someone help me with the hole tolerance that is needed in order for it to be a slip-fit? Any reference (URL, book, etc.) of where you found your answer is always welcome. Thank you very much!

 

[desertfox]

Hi

Try this link

http://www.cobanengineering.com/Tolerances/ISOHoleandShaftBAsisLimitsAndFits.asp

 

[tbuelna]

MrFrench24,

A slip fit under what conditions? Obviously, due to the CTE mismatch existing between your steel pin and aluminum bore, the fit condition will change with temperature.

As a general rule, it is usually easier to control the tolerance of a ground steel pin than a drilled/reamed aluminum hole. So bias your tolerance allowances accordingly.

 

[MrFrench24]

desertfox,

Your post helped a lot! Thanks!


tbuelna,

It is under normal room temperature conditions, ~70 Fahrenheit. Yes I understand that it is easier to control the tolerance of the ground steel pin, thank you!

--

 

[desertfox]

Hi

Your welcome.

Desertfox

 

[ornerynorsk]

Depends how critical the application, of course. A rough rule of thumb in the machine shop is to use a 0.3760 reamer for a 3/8 dowel pin. The pin should actually measure ~0.3752.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.