I have finally finished some 4HP adjustable pulleys. See attached photos.
The pulley and the outer locking nut is machined from K1045 steel. The inner nut is made from high tensile 4140.
The drilled holes in the pulley are square to the pulley face, as originally made.
The nuts are 9/16" x 10TPI Whit form, left hand thread.
I have 3 pulley for sale but have more inner and outer locking nuts which I can sell separately.
The mainshaft in the photos is for photographic purposes only (not for sale).
Contact me via private message if you are interested and I can give you more details.