It was me not paying attention to the dates of the last post. The bandsaw
axle sort of got my attention. I bought a DoAll model C-80 out of the
scrap yard for 400 bucks a while ago and had to make new spindles for it.
The bearings had spun on the axles and they had to be replaced as well as
the bearings. The metal I used was from some of the scrap of the pins I
made of the 4140. I still have a barrel full of the out of tol. pins
accumulated over the years. I just used another piece today to make up a
lathe chuck wrench. By the way to get a good finish on the metal you have
to take at least ten thou. per side and turn at least 300 ft/min.


John

Is that the 4140 without sulfur? It's been so long since I've turned that
alloy that I can hardly remember it.



I switched suppliers after that bad batch and had no more problems with
cutting the metal. We had to supply certifications so I kept an eye on
the sulfur content and made sure it was always on the high end of the
limits. It ran on the high end of the permitted amounts, I only machined
it and didn't weld on it. I think the percentage ran about .18 At that
percentage it would run well at those speeds. The part we ran required
holding +/- .0005 in. on 6 inch turn and once the machine stabilized it
ran all day with almost no scrap. The only problem was the air chuck
would sometimes not hold the piece properly and it would slip if we had
the feed or rpm running too high. I made thousands of those parts.