[jbranson]

Just heat treated my first piece of metal. It's a mandrel for expanding exhaust pipe for slip fits. Worked before but it was hard to push in and pull out because the pipe would grab hold of it pretty good, and it was starting to show some signs of wear.
Heat treated that baby and now a file slides on it like it's made of glass. It's 1" thick so I don't have to worry about it cracking...and it's not under any bending loads anyway.
Tried it on another mandrel...didn't work...then I noticed I didn't make the other mandrel out of "hardening" steel like the first one.

Just had to tell someone.
JohnnyB

 

[RookieGeorge]

One step closer to bending 350T headers, we all hope?

 

[jbranson]

I'm one lazy mofo.

JohnnyB

 

[parks61]

my mandrill is usually hard to push in and pull out at first too. those pipes do grab hold pretty good sometimes.
parks.

 

[jbranson]

I hate it when the mandrel goes soft before the job is finished.

JohnnyB

 

[joe c]

dont you mean man-drill?

jc

 

[craig641]

So JohnnyB, other than making your man-drill rock hard, could you use your heat treating capabilities for something like rocker arms for old Honda twins? Would it help them? I know megacycle does something like this but I'm not sure of the whole proceedure. And I'd much prefer sending my rocker arms to the Clever Dog Racing shop...
Craig

 

[jbranson]

Craig...unfortunately rockers need to be hard in certain places and not so hard in others. Pads need a hard surface...like chrome...but the rest needs to be "tough" like the tappet end. If you hardened the whole pad end...it would probably snap off eventually.

I'm trying to come up with race bike uses...but for the most part it's for making tooling to make race bike parts. Would work for valves spring base washers, gears (after tempering), any part that could stand to be a bit brittle and was susceptable to wear. Valve stem ends for instance....just the very end though.
JohnnyB

 

[Camelhairy]

quote:
I'm trying to come up with race bike uses...but for the most part it's for making tooling to make race bike parts. Would work for valves spring base washers, gears (after tempering), any part that could stand to be a bit brittle and was susceptable to wear. Valve stem ends for instance....just the very end though.
JohnnyB

JB,
I'm going to harden my rear axle spacers. They don't have much area where they contact the bearing race so wouldn't be prone to squashing down. I make the end that bears against the SA very large because it only contacts above and below the axle slot. I think it will make the SA a little stiffer.

FC

 

[jbranson]

Frank,
Real good point...I tend to do the same thing as far as putting a larger bearing area on the SA. Same deal..that slot makes me nervous. Course I usually make oversize aluminum spacers. Sometimes I'll put a hardened washer on the bearing side.
Yeah...wheel and bearing spacers would be a good use for hardened steel.
I could also go to a smaller chain size now, anneal the sprockets, do the machining, reharden it. Last time I tried to machine a hardened counter sprocket it didn't work out so good.
I also want to use a high temp oven to start melting some aluminum and casting some small one off pieces.
JohnnyB