Author Topic: Machining 01 steel  (Read 888 times)

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7573
  • Barrie, Ontario Canada
Machining 01 steel
« on: December 03, 2022, 01:34:22 AM »
I have a question regarding 01 steel. I have a camshaft and cam all made from one piece of 01 steel. I heated the camshaft to cherry red, then dumped it into a can of oil to harden it. Worked great, piece is now harder than the devil's horn. Today I discovered that it has to be changed---more machining. I THINK that it can be returned to the relatively soft state by heating to cherry red, then letting it air cool, but I'm not certain of that. I have to put in a couple of #4-40 threaded holes and I don't want to break a tap. After the threading is completed, I want to heat it cherry red again and drop it back into the oil to reharden it. I haven't done this before, and I'm working from very old memories. Can someone confirm that this is the way to go about it please.---Brian

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Machining 01 steel
« Reply #1 on: December 03, 2022, 02:18:48 AM »
Some temp info here:

https://www.groundflatstock.com/News/ArtMID/1382/ArticleID/10/O1-Tool-Steel-Heat-Treatment-Information

And that temp range would correspond to between dark red and cherry red. You would want to cool slowly, so air cooling would be rapid for a small part compared to cooling in a furnace, or buried in a bucket of wood ashes.
« Last Edit: December 03, 2022, 02:34:34 AM by vtsteam »
Steve

Offline steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12697
  • Central Massachusetts, USA
Re: Machining 01 steel
« Reply #2 on: December 03, 2022, 03:12:26 AM »
Hi Brian,

0-1 in full hard condition is quite hard. (Harder than woodpecker lips is the last definitive specification I'm familiar with,  60+ Rc )   If there is any possibility to do something other than trying to tap it  I would do that.    Annealing will probably distort it .

You might be able to get a hole in it with carbide, but I wouldn't try to tap it conventionally.   Do you know someone who can do EDM?

Dave
« Last Edit: December 03, 2022, 03:51:00 AM by steamer »
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12697
  • Central Massachusetts, USA
Re: Machining 01 steel
« Reply #3 on: December 03, 2022, 03:38:11 AM »
Plus 1 for burying in some ashes or perhaps hot sand to let it cool slowly  Maybe vermiculite?

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline john mills

  • Full Member
  • ****
  • Posts: 417
Re: Machining 01 steel
« Reply #4 on: December 03, 2022, 10:16:29 AM »
years ago i worked where they annealed and re shaped tools made in tool steel it was annealed buy heating in a gas muffle furnace
then covered in a tub off i think it was lime and left to cool it was soft enough to file .ground stock would always be hardened and tempered
never just hardened . often for high strength and toughness tempered back to 48 RC and often 52 RC.
John  l

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7573
  • Barrie, Ontario Canada
Re: Machining 01 steel
« Reply #5 on: December 03, 2022, 04:43:53 PM »
I just put the cam shaft in my vice and heated it to cherry red, and I'm leaving it to air cool. I don't have any vermiculite. ---I do have another unhardened piece of 01 steel, so if I need to I can make another camshaft. After this one cools, I will let you know how much success I had threading very small holes in it.

Offline internal_fire

  • Full Member
  • ****
  • Posts: 204
  • Punta Gorda, FL
Re: Machining 01 steel
« Reply #6 on: December 03, 2022, 05:01:45 PM »
The "book" says to cool at 50 degrees F per hour. No way that can be done for a small part in air or buried in anything. A controlled furnace would be the only way to achieve that rate.

Gene

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7573
  • Barrie, Ontario Canada
Re: Machining 01 steel
« Reply #7 on: December 03, 2022, 07:35:07 PM »
And the story is---No, it didn't work for me. The part is still very hard. I could turn a bit off the o.d. with a carbide cutting tool, but no way was I going to be able to drill and tap it for #4-40 threads. That's okay. I have lots of unhardened 01 to make a new cam shaft, and I've learned something today.---Brian

Offline crueby

  • Full Member
  • *****
  • Posts: 18554
  • Rochester NY
Re: Machining 01 steel
« Reply #8 on: December 03, 2022, 07:44:07 PM »
Brian, as I recalled you had built a small heat treat furnace, just looked back for it...
https://www.modelenginemaker.com/index.php/topic,10328.0.html

Wouldn't that work for doing a long heat followed by a slow cool down?
Chris

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7573
  • Barrie, Ontario Canada
Re: Machining 01 steel
« Reply #9 on: December 03, 2022, 09:12:57 PM »
Chris--I don't really know. I had heard that 01 steel could be returned to its soft state by heating to cherry red, then letting it air cool, but like a million other things, I don't really believe it until I've tried it. There may be a way to return hardened 01 to it's soft state with a heat treating furnace, but I don't know about it. It really isn't a big deal--I can remake the camshaft and cam in about two hours, and I have the material. I have heard of so many ways of doing so many things, that when they've laid me out in my coffin I'll be wondering "Hmmm---I wonder if this method or that method really works?"  There are literally hundreds of "old time machinists tricks" that I will probably never live long enough to prove or disprove. I never forget anything I've heard, seen, or read about, but I take all of this with a grain of salt until I've actually tried it myself.---Brian

Offline crueby

  • Full Member
  • *****
  • Posts: 18554
  • Rochester NY
Re: Machining 01 steel
« Reply #10 on: December 03, 2022, 09:42:11 PM »
If you google 'Annealing O1 Steel' there are a couple of the early entries that show up from commercial suppliers that give the temperatures and times that they use.  Here is one from Hudson steel:
Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1425 -1450°F (802-816°C), and hold at temperature for 1 hour per inch (25.4mm) of maximum thickness; 2 hours minimum. Then cool slowly with the furnace at a rate not exceeding 50°F per hour (28°C per hour) to 1000°F (538°C). Continue cooling to ambient temperature in the furnace or in air. The resultant hardness should be a maximum of 212 HBW.
 

Offline steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12697
  • Central Massachusetts, USA
Re: Machining 01 steel
« Reply #11 on: December 04, 2022, 02:15:29 AM »
tough to follow a process like that with little more than a torch..  unfortunately.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline mcostello

  • Full Member
  • ****
  • Posts: 84
  • Lancaster, Ohio
Re: Machining 01 steel
« Reply #12 on: December 04, 2022, 05:45:13 PM »
Wonder if a piece of pipe filled with dry sand and capped off would work?

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal