View Full Version : ~!@#$%^&*() Gates belt nomenclature

02-06-2012, 05:40 PM
Made up a little machine with two sheaves. Bought a 48" belt at the auto parts store, was a bit too long. I figured it needed about a 46" belt. Went on ebay - aha, a Gates B46, only 5 bucks free shipping. Ordered it. Took 2-1/2 weeks to get here, only to discover that for Gates, a B46 belt isn't 46 inches long. Oh, no - that would be too simple! It's 49 inches long.

Today I drove down to Grainger and bought a B43 46" belt. Fits.

Dag nabbit.

Moral of the story is, never trust belt nomenclature again.


02-06-2012, 08:32 PM
Was there a mention of outside or inside length?

02-06-2012, 09:47 PM
I believe the confusion arises from the switch by belt manufactures to now use datum diameter instead of outside diameter or pitch diameter.
Except for fractional HP belts....I think.:D :confused:

02-06-2012, 10:35 PM
A funny thing happens with multi V belts. I run one on my South Bend on regular flat belt cone pulleys. The belt is a very different length depending on which side is out.

Edwin Dirnbeck
02-06-2012, 10:37 PM
Not to hijack your thread, but for years I have been cursing the sizes of pins used in mold making .Example a 1/4 inch core pin is a c17,yes exactly one number higher than the number of 64 ths of the pin size and a 15/64 pin is ,you guessed it a size 16.And they have sold millions of these things.Maybe their buisness plan is to sell more pins because people order the wrong ones and then are too lazy to return them. Or maybe DME started out as a saw mill where the finished product such as a 2x4 is defined by the ruff cut size. WEW, rant over . Edwin Dirnbeck

02-06-2012, 11:45 PM
Years ago, the Gates fractional horsepower belts were labeled with a 4 digit number, the first digit indicated the width in 1/8ths (4250 was a half-inch belt, 25 inches around the outside). The Industrial belts, however, were labeled A, B, C and a number, the letter indicating the width and the number indicating the circumference along the centerline of the belt about halfway between the 'top' and the 'bottom') If that is still the case, it may explain your problem.