Shop Floor Talk  

Go Back   Shop Floor Talk > Welding and Metalworking Forums > Blacksmithing & Forming

SFT Search:   
Reply
 
Thread Tools Display Modes
  #1  
Old 10-24-2007, 06:13 AM
clive's Avatar
clive clive is offline
 
Join Date: May 2007
Location: Western Australia
Posts: 1,897
Default Tempering chisel steel

I had an apprentice make, harden and temper a chisel today. He did what I have always done, after he had forged it he dressed it up on the grinder and then heated the end red, plunged 1/2 of it in water and then cleaned it with emery quickly and waited till it turned straw and plunged it in the water.
He had done a beautiful job of shaping it but when I looked at it there was a crack through, which subsequently broke off when I smacked it with a hammer.
I had done several chisels earlier by this method without any problem. The only thing I can think of is that when he was forging he didn't have it hot enough and kept hammering when he should have had it back in the heat. Plus the chisel could still have been a bit red when he plunged it a second time Any suggestions?
Clive
Reply With Quote
  #2  
Old 10-24-2007, 06:57 AM
OZWELDER's Avatar
OZWELDER OZWELDER is offline
Senior Member
 
Join Date: Mar 2007
Location: Mackay, Queensland.Australia
Posts: 634
Default

G'day Clive,

The steel is probably an oil quench rather than a water quench.

Ozwelder
Reply With Quote
  #3  
Old 10-24-2007, 02:09 PM
Brian C.'s Avatar
Brian C. Brian C. is offline
Director of Security
 
Join Date: Nov 2006
Location: Waverly, OH
Posts: 2,844
Default

Quote:
Originally Posted by OZWELDER View Post
G'day Clive,

The steel is probably an oil quench rather than a water quench.

Ozwelder

My thoughts exactly, but then again I am no metallurgist.
__________________
"Getting old aint for sissies"

Admit nothing, deny everything, demand proof

Millermatic 211
Harris oxy/act.
2 propane forges
147 lb. Peter Wright anvil
Reply With Quote
  #4  
Old 10-24-2007, 03:54 PM
EMF EMF is offline
Junior Member
 
Join Date: Sep 2007
Location: Las Vegas, Nevada
Posts: 32
Default

I learned that it was "high red', then oil quench when it got back to "wheatstraw"; no water involved; worked real well for the gad end and chisel end of mining picks. The blacksmith who was our teacher/mentor could stick a pick in the flank of an anvil and it would stay; we made and tested our own slag hammers the same way.
__________________
EMF - Messin' with stuff for some 60 years, or so.
Reply With Quote
  #5  
Old 10-24-2007, 06:02 PM
clive's Avatar
clive clive is offline
 
Join Date: May 2007
Location: Western Australia
Posts: 1,897
Default

Yes, I am leaning towards the oil quench too, I will have to experiment with it over the next few days.
Thanks
Clive
Reply With Quote
  #6  
Old 10-24-2007, 06:59 PM
precisionworks's Avatar
precisionworks precisionworks is offline
American Tools Keep Americans Working
 
Join Date: Oct 2005
Location: Benton, IL
Posts: 3,177
Default

Water quench is pretty violent, some steels are made to withstand the shock (W1 for instance), others need the more gentle oil quench. Some steels, like A2, are "quenched" in still air.

Oil is probably the safest medium.
__________________
Barry Milton - Please email or PayPal through PrecisionWorks.co
PM's are disabled
Reply With Quote
  #7  
Old 10-25-2007, 12:26 AM
ace4059 ace4059 is offline
Tender Member
 
Join Date: Dec 2006
Location: Wichita Falls, Texas
Posts: 819
Default

I have a question: It maybe stupid but what oil do you guys use.
The reason I ask is because it seems to me, some oils would burst into flames if you placed red hot metal in them.

-Ryan
__________________
Lincoln Pt 225
Lincoln PM 215
Lincoln Buzz Box

Hypertherm 600
HH125 EZ
MM 350P
TB 302



Quote:
Originally Posted by Shade Tree Welder View Post
Calling an illegal alien an "undocumented immigrant" is like calling a drug dealer an unlicensed pharmacist.
Reply With Quote
  #8  
Old 10-25-2007, 01:34 AM
Brian C.'s Avatar
Brian C. Brian C. is offline
Director of Security
 
Join Date: Nov 2006
Location: Waverly, OH
Posts: 2,844
Default

Many oils are suitable. Never use old motor oil Use in a container of sufficient volume and has a lid you can drop quickly to smother any flare ups
__________________
"Getting old aint for sissies"

Admit nothing, deny everything, demand proof

Millermatic 211
Harris oxy/act.
2 propane forges
147 lb. Peter Wright anvil
Reply With Quote
  #9  
Old 10-25-2007, 01:56 AM
Dave Lee's Avatar
Dave Lee Dave Lee is offline
Armchair Webbie
 
Join Date: Jan 2007
Location: near Philadelphia, PA.
Posts: 3,575
Default

When I first started in the tool & die shop, they had a 5 gallon can full of refridgeration oil that they used for quenching. I'm sure the only reason was because we manufactured water coolers (called bubblers or drinking fountains elsewhere), and we had the stuff in abundance. It worked but, there was always a little flame as the part was plunged into the oil. Later on, we got a production engineer in that, had a very good chemical background and suggested quenching oil would be much safer. There was no flame with this stuff. We only heat treated little, "hurry-up jobs" in house and quenched the parts down cool enough to handle. Then, polished them up and reheated them to show the oxide colors and quenched them again. I'm sorry, but, I don't know who made the stuff. Maybe, Shade Tree can help here. The guy who ran the shop before I took over loved his 0-1 because he could heat treat a lot of his stuff in house. I hated the stuff because it warped so much that you had to leave a lot of excess material on for surface grinding to final size. We switched to A-2 after he retired. Beautiful stuff. We also used D-2 if the die would run a lot of stainless steel. Nasty stuff to grind. One pass across and back and the wheel needed dressing. What a pain!

Dave
__________________
Hoocha Momma!, who chop-id-da cheese?

Last edited by Dave Lee; 10-25-2007 at 02:15 AM.
Reply With Quote
  #10  
Old 10-25-2007, 04:06 AM
clive's Avatar
clive clive is offline
 
Join Date: May 2007
Location: Western Australia
Posts: 1,897
Default

OK, I went back to the stores and asked what steel they got, they said "we couldn't get what you asked for so we got something else" my fault for assuming they would let me know of any problems. So I went to the supplier and it is AISI S1 which anneals at 760oC, hardens 860-900oC in "oil or hot bath 180-220oC" (quote). According to their chart it is tempered at 550oC for 2 hours.We have an electric oven which goes up to 1200oC so that is that problem solved I hope. I will try it in oil at 180oC next week.
Thanks for your replies they are appreciated.
Clive
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Web Search:

All times are GMT -5. The time now is 01:04 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.