H BUSHED BORE SINGLE GROOVE PULLEY Brand new. Fractional HP, single groove, cast iron pulley. Use with a H-type split taper bushing (sold separately). For use with type "A" and "B" belts. Fully balanced. (Click here to see the corresponding H bushings)
Outside Diameter 7.75"
Belt Type A (1/2") Datum Diameter 7.00"
Belt Type B (5/8") Datum Diameter 7.40"
Shpg. 5 lbs.
Outside Diameter Diameter measured at the outside of the pulley.
Datum Diameter The datum diameters are an industry standard reference point used for calculations such as center distance and belt length. The datum system replaces the pitch system for classical belts and pulleys to compensate for differences in manufacturers construction of belts.
I am replacing an air compressor pump. The new pump has a different dia. pulley. According to the formula for sizing and the speed of my motor I need to use a 7.5" pulley. Should I get one based on actual outside dia. or the Datum dia. to turn the pump at the proper rpm?
A: If using 5/8" (B) belts; use the o.d. of the pulley for calculation. If using 1/2" (A) belts; add 0.375" to the datum diameter for the o.d. where the back side of the belt will ride.