02-27-2018, 04:00 AM
(This post was last modified: 02-27-2018, 08:39 AM by doug tenney.)
This has nothing to do with the title of the thread, but... it was a pain figuring this out, so I figured I'd share it.
[Mr. Luciani, if you concur with these numbers, it might be good to put them somewhere... unless you already have.]
On the PTO side, Mc91x cranks use a Woodruff key defined by these numbers: SAE #213, ANSI #403, McMaster-Carr #98481A075. The slot in the crank is nominally 0.336" long.
(Mc92 and Mc93 cranks are 0.100 longer on the PTO side, and have LH threads, like Teddy said. The extra length was added when Space Chain came along. Without this extra length, the chain has to eat its way into the block for clearance.)
Older McCullochs (sorry, I don't know the cut-over) use a larger key on their PTO: SAE #3 = ANSI #404 = McMaster-Carr 98481A090. The slot in the crank is nominally 0.444" long.
WB610/WB820/US820 with the kart-type 5/8" - 9/16" stepped crank use a Woodruff key defined by these numbers: SAE #8 = ANSI #506 = McMaster-Carr 98481A120. Basically, same as Teddy said.
The ANSI 3-digit numbering system, defined in ANSI B17.2:
1st digit = width in 32nd's of an inch. 4/32 = 1/8".
2nd and 3rd digits = dia of the Woodruff key's "circle" in 8ths of inch.
[Mr. Luciani, if you concur with these numbers, it might be good to put them somewhere... unless you already have.]
On the PTO side, Mc91x cranks use a Woodruff key defined by these numbers: SAE #213, ANSI #403, McMaster-Carr #98481A075. The slot in the crank is nominally 0.336" long.
(Mc92 and Mc93 cranks are 0.100 longer on the PTO side, and have LH threads, like Teddy said. The extra length was added when Space Chain came along. Without this extra length, the chain has to eat its way into the block for clearance.)
Older McCullochs (sorry, I don't know the cut-over) use a larger key on their PTO: SAE #3 = ANSI #404 = McMaster-Carr 98481A090. The slot in the crank is nominally 0.444" long.
WB610/WB820/US820 with the kart-type 5/8" - 9/16" stepped crank use a Woodruff key defined by these numbers: SAE #8 = ANSI #506 = McMaster-Carr 98481A120. Basically, same as Teddy said.
The ANSI 3-digit numbering system, defined in ANSI B17.2:
1st digit = width in 32nd's of an inch. 4/32 = 1/8".
2nd and 3rd digits = dia of the Woodruff key's "circle" in 8ths of inch.