SAE Shaft Taper Specifications - NB:   Boss taper will be longer than shaft to allow for correct pull up

While Kiwiprops™ smallest boss is bored 1" - they can be adapted to both SAE 7/8" and SAE 3/4" shafts by using an adaptor sleeve from Tacoma Propeller who also supply the required rectangular key to match the keyway on the shaft with the 1/4" keyway on the 1" Boss. Kiwiprops™ will supply the required 5/8" or 1/2'' UNC nuts.

IMPERIAL THREAD SIZES in TPI or Threads per Inch used on imperial shaft sizes.