Anybody knows the correct temperature to temper it to ~ RC 40-45 after
hardening?

This is 3/4" rod.

cheers
T.Alan

In article ,
says...
Anybody knows the correct temperature to temper it to ~ RC 40-45 after
hardening?

This is 3/4" rod.

cheers
T.Alan


You're off the charts, but 1100F would give you about Rc50. A2 is not
generally recommeded for use below Rc55-57 - if you need extra toughness
there are better choices.

Ned Simmons

Thanks, would oil hardening O1 be better?

cheers
T.Alan




You're off the charts, but 1100F would give you about Rc50. A2 is not
generally recommeded for use below Rc55-57 - if you need extra toughness
there are better choices.

Ned Simmons

In article ,
says...
Thanks, would oil hardening O1 be better?

cheers
T.Alan




You're off the charts, but 1100F would give you about Rc50. A2 is not
generally recommeded for use below Rc55-57 - if you need extra toughness
there are better choices.

Ned Simmons


Probably not. What combination of properties are you looking for?
Rockwell hardness is often not an end in itself, rather it's a
convenient indicator of the overall properties of a chunk of specific
material. For example, toughness and wear resistance will vary widely
between different materials of equal hardness.

Since you're asking about drawing back to Rc40-45, I assume you're
looking for something relatively strong and tough. In that case, 4140,
or a similar alloy steel, is a possibility. A socket head cap screw is
an example of alloy steel in this hardness range.

Ned Simmons

I am searching for some easy to get round stock that is dimensionally
correct without having to turn it, and is wear resistant enough to
accept a bearing while enduring heavy side loads. Something like an
axle. I'm aware of prehardened 4140 to RC 35-40 that is still
machinable, but I haven't been very happy with the finish I was able to
turn it to.

cheers
T.Alan

Probably not. What combination of properties are you looking for?
Rockwell hardness is often not an end in itself, rather it's a
convenient indicator of the overall properties of a chunk of specific
material. For example, toughness and wear resistance will vary widely
between different materials of equal hardness.

Since you're asking about drawing back to Rc40-45, I assume you're
looking for something relatively strong and tough. In that case, 4140,
or a similar alloy steel, is a possibility. A socket head cap screw is
an example of alloy steel in this hardness range.

Ned Simmons

In article ,
says...
I am searching for some easy to get round stock that is dimensionally
correct without having to turn it, and is wear resistant enough to
accept a bearing while enduring heavy side loads. Something like an
axle. I'm aware of prehardened 4140 to RC 35-40 that is still
machinable, but I haven't been very happy with the finish I was able to
turn it to.


If all you need is a straight shaft, Thomson shaft should do the trick.
It has a hard case and a tough core. The usual stuff is .0005-.0010
under nominal, but there are other diameter limits (Thomson call them
"classes") available. McMaster carries the standard class in inch and
metric sizes starting on p.988. The hard case is machinable with
carbide, or it's possible to spot anneal with a torch, though it's best
to do this only on the ends of a piece if you need to maintain
straightness.

Dowel pins are another possibility if you just need a simple pin.

If you need a more complicated shaft, "stressproof" will approach the
4140 prehard in strength/toughness, but is much nicer to machine. But it
will not be accurate enough as-is to use in a bearing. Look on the
bottom of McMaster page 3441.

Ned Simmons

Thanks Ned, good info.

cheers
T.Alan

If all you need is a straight shaft, Thomson shaft should do the trick.
It has a hard case and a tough core. The usual stuff is .0005-.0010
under nominal, but there are other diameter limits (Thomson call them
"classes") available. McMaster carries the standard class in inch and
metric sizes starting on p.988. The hard case is machinable with
carbide, or it's possible to spot anneal with a torch, though it's best
to do this only on the ends of a piece if you need to maintain
straightness.

Dowel pins are another possibility if you just need a simple pin.

If you need a more complicated shaft, "stressproof" will approach the
4140 prehard in strength/toughness, but is much nicer to machine. But it
will not be accurate enough as-is to use in a bearing. Look on the
bottom of McMaster page 3441.

Ned Simmons

Just as a comment, I've seen some pretty nice stuff turned (and milled) from
4140 Rc 35-40.
Perhaps a closer look at the tooling/setup/methodology you are using?? At
any rate, good luck!

Ace

"T.Alan Kraus" wrote in message
...
I am searching for some easy to get round stock that is dimensionally
correct without having to turn it, and is wear resistant enough to accept a
bearing while enduring heavy side loads. Something like an axle. I'm aware
of prehardened 4140 to RC 35-40 that is still machinable, but I haven't
been very happy with the finish I was able to turn it to.

cheers
T.Alan

Probably not. What combination of properties are you looking for?
Rockwell hardness is often not an end in itself, rather it's a convenient
indicator of the overall properties of a chunk of specific material. For
example, toughness and wear resistance will vary widely between different
materials of equal hardness.

Since you're asking about drawing back to Rc40-45, I assume you're
looking for something relatively strong and tough. In that case, 4140, or
a similar alloy steel, is a possibility. A socket head cap screw is an
example of alloy steel in this hardness range.

Ned Simmons