Fit sizes
Fit sizes
(OP)
Can anyone help me find the hole fit sizes for standard dowel pins (ground .0002 over)? I am not a mechanical engineer and I find that using the machinery's handbook can be somewhat confusing.
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RE: Fit sizes
RE: Fit sizes
RE: Fit sizes
RE: Fit sizes
Arto recommended ANSI B4.1, but he did not tell you where to find it. Look in the Machinery's Handbook under Limits and Fits. There are several pages of tables with fit classes labeled in fairly plain English and described briefly.
I use FN1 fits to press-fit dowel pins. The RC class fits will provide the sliding fits you want. I do not know how precise you want to be. Probably, you should chat with your fabricator.
If you drill your holes after assembly, I do not see any problems. Otherwise, one of your sliding holes should be a slot. This accounts for the errors in locating holes.
JHG
RE: Fit sizes
A google search has a few billion hits, one that I thought interesting was this:
http:/
some shareware for $14 that you can try for free(?), says it references B4.1
TygerDawg
RE: Fit sizes
RE: Fit sizes
For super precise repeatability (1 micron or less), consult a mechanical engineer and have him design a kinematic coupling (only slightly more expensive).
Tom
RE: Fit sizes
Don't let references to things like H7/f6 bother you. These come from ANSI B4.2, which is described just after ANSI B4.1 in the Machinery's Handbook.
If you look at the limit and fit charts you will see these letters at the top of the column. For FN2, you will see H7/s6. For FN1, the shaft is not based on ASME B4.2.
Since you have no control over the size of a standard dowel pin, you will have to calculate tolerances from the column lateled "interference" or "clearance".
JHG
RE: Fit sizes
For Transitional fit use H7 hole, with an E9 for a Clearance hole.
RE: Fit sizes
http://www.driv-lok.com/Dowels%20Pins.htm
http://www.groovepin.com/pin-what.htm