[Brian FRF]

We need to broach some splined holes, about 1.23 ID bore, fine spline, so only 1.3" at Spline major on the female

Everything I can find says rotary broaches are limited to 1". Spline count is 30, so Im trying to determine a way to cut this spline without shaping each one.

Any way to use a rotary broach for this, or should I shape, or spend a fortune to get staged bottoming broach set made up.

Working in 4340 material, annealed or normalized. Only wanting a small run for now, 10 pieces. Depth is 1-1.5" of spline, and I can have a good amount of clear bore beyond the spline, up to an inch Id say.

[florida]

Brian,
With such a large diameter, you may be able to swallow a part of the rotary broach tool holder and reach deeper than 1". The critical dimension is the tooth height, or material removal per side. Less than .025" per side is ideal. We can make some modifications to the broach to help with the tougher alloy material. Do you already have a broach holder? Call me at Polygon Solutions for a phone chat.(Peter)