General comment on V-belts and V-belt nomenclature. Fractional horsepower belts (those with an Industry part number beginning with the numerals 2, 3, 4 or 5 and with the second character being the letter "L") should not (often cannot) be interchanged with those with part numbers beginning with the letters "A" through "E". The latter are heavier belts intended for use where the load requires two or more belts in parallel. They are called "Multiple V-belts". The only Atlas application that used multiple V-belts were the cabinet model 12" which used two A42's on the spindle. With FHP belts, the first digit is the nominal outside belt width in eights of an inch (except for "5" which is 21/32"). The digits following the letter L on the FHP belts are the nominal belt length at the OD in tenths of an inch. So a belt with a part number ending in "330" would be approximately 33" in outer circumference. Multiple V-belts have their lengths specified at the pitch diameter (roughly the midpoint between the ID and the OD) and the part numbers are only rough indicators of the pitch length. For example, the nominal pitch length of an A42 is 43.3".
Robert D.