How to read a pulley/sheave number

[Bill D]

I can not remember how to read the numbers on a vee belt pulley. All I find are about cogged belt timing pulleys or measuring groove wear with a gauge. I looked at several makers web sites and could not find this information just cross reference look up links or contact us.
The makers are even unclear on the distinction between pulley and sheave. I thought sheave was a vee belt wheel while a pulley was for rope and transmitted no torque.

I know the first number and letter is belt size after that I get lost. I know diameter is in there somewhere. Reminds me of decoding insert nomenclature.
Bill D

 

[Doozer]

I am not sure if belt pulleys have an industry standard numbering system.
Like an 1157 is a tail light bulb.
Most casting have mold numbers. Maybe that is what you are seeing.
Like core box revision and date code.

-Doozer

 

[seiner]

left to right?????

 

[4GSR]

Some sheave manufactures years ago would list them by pitch diameter as part of the part number.

Yeah, they were all right handed.

 

[millwrong]

Usually the first number relates to the number of grooves. Then belt cross-section, and then pitch diameter. So a 3B 82 means three groove, B cross-section and 8.2 inch pitch diameter. However since power transmission products have been "outsourced" both quality and nomenclature has certainly degraded!

 

[Bill D]

Millwrong I think you have it. More reasearch says you are correct leading number, if any, is groove count, belt size then pitch diameter. Problem with pitch diameter is it can be one two or three digits. Single digit is diameter in inches.
Two digit is diameter in inches or inches plus 1/10". So you need to know if it is more then 10 inch diameter.
The three digit diameter may be cm? Not really sure on that.
Letters at the end for mount type. I think plain bore is no letter.
Bill D

 

[metalmagpie]

One good trick is to stop the machine before trying to read those numbers. Otherwise your head will spin.