AJUN 740 by Skip Albright, on Flickr

so I have some older line shaft and pulley stuff, it's cool but puzzling.

none of the measurements are what I might call  'standard"

I really dont think they are metric, but they are odd.

pulley pictured is 12 and 1/16 in diameter  the width is dead on 3 inches, but the bore is  1.175, not quite 1 1/8

I guess some of the oddnes could be rust, but I have several different parts and all are not "quite" right.

Is this like the SAE bolt size thing from the 20's?

or were there proprietary sizes for different companies?

have you check the line shafts with a micrometer ???

check both ends & then somewhere where no pulleys were.

you might have to shim the pulleys.

1.175" bore is ~ 3/64" larger than 1 1/8", could be wear,
check top middle & bottom 3 places ~60deg apart. may need a shim ~1/64+ to fitup tight.
also it has a lock screw, so doesn't need to be press-fit, just center alignment to minimize vibration..

In the days of lineshaft drives, every manufacturer did his own thing his way, and bastard sizes were the rule rather than the exception.  If I'm making shaft and shaft accessories and you make a similar product, I do not want my pulley to fit your shaft, and you don't want yours to fit mine.  That way we each lock in our customers and guarantee future sales.

Then along comes a company called Browning who sell universal wood lineshaft pulleys and include half a dozen sizing sleeves with each pulley leaving the factory.  One size fits all.  Didn't take long for Browning to capture the industry.

It got even worse when ball bearings arrived and everything went to 1 3/16 diameter.  No more captive market for anybody.