These wretched things are driving me up the wall ...
I want to pin a Hostaform gear to a 8mm S.S. shaft. Not what you might call particularly heroic, been done before I'm sure.
I have a kit of roll pins, all sorts of sizes but NO INFO. re: dimensions.
So I have no idea whether they are supposed to be Metric, Inch or a mixture ..
Just squandered about 2 hours of my remaining days on Earth measuring the damn things. Well, some of them.
The only conclusion I can draw is, unless some are 64
ths they are metric. But not dead to size.
BUT .... here's the clever bit .. IF I assume they are in increments of 0.5mm AND are 6% oversize they seem to make sense.
ie. 2mm = 2.12mm ; 2.5mm = 2.65mm etc. etc.
This does seem the hold true up to 6mm. ( Didn't bother any further. Even I can work out a 8mm hole through a 8mm shaft is not likely to work too well ).
So, the question is this:
Would it be correct to ream a 2mm hole through the gear boss and shaft and then stick the 2mm roll pin in?
Is that why the apparent 6% oversize is there ?? Dunno ...
I cannot seem to find ANY real info. on the net ... bugger ...
I did find this:
https://www.engineersedge.com/roll_pin.htmBut the dimensions given, even allowing for the tolerances, don't match up.
Dave