MEMBER ITEMS FOR SALE
Custom Knives | Other Knives | General Items
-------------------------------------------
New Posts | New PhotosAll Photos



Go Back   The Knife Network Forums : Knife Making Discussions > Custom Knife Discussion Boards > Knife Making Discussions > The Newbies Arena

The Newbies Arena Are you new to knife making? Here is all the help you will need.

Reply
 
Thread Tools Display Modes
  #1  
Old 06-02-2013, 05:35 PM
JawJacker's Avatar
JawJacker JawJacker is offline
Steel Addict
 
Join Date: Sep 2012
Location: Georgetown, DE
Posts: 139
Temper question

I waited a few days until I tempered a blade, was that OK?
Reply With Quote
  #2  
Old 06-02-2013, 06:15 PM
WynnKnives's Avatar
WynnKnives WynnKnives is offline
Steel Addict
 
Join Date: Apr 2012
Location: Wooster, Ohio
Posts: 242
Traditionally I think most would suggest to temper them within a day, some people cryo there blades so that takes time and such. I think I've heard the arguments and such about tempering them asap, but I can't recall the exact reasoning. I'm trying to figure out why it would make a huge difference (all outside effects that would come into play, rusting ect. not into the equation), I don't know what would make the crystalline structure (or why) change once it's been cooled to room temperature, which you do before tempering.

But I'm sure someone will stumble by that knows the scientific reasoning, or why it doesn't matter. I have a metallurgy book that I used for a class I took years ago about 15 ft. away, but honestly I'm just too lazy at this point in time.
Reply With Quote
  #3  
Old 06-02-2013, 06:44 PM
Ray Rogers's Avatar
Ray Rogers Ray Rogers is offline
Founding Member / Moderator
 
Join Date: Jun 2002
Location: Wauconda, WA
Posts: 9,840
It's best to temper immediately after the quench as a rule of thumb but, in fact, it can vary with the steel in question. Tempering is done partly to soften the steel so that the blade is durable but also to relieve stresses in the steel caused by the quench. Many steels can quite literally tear themselves apart in a few hours if left untempered. Usually, this is very visible and obvious but it is possible that small cracks form that might not be visible until the blade fails at some later date after being made into a finished knife . I watched one of my untempered blades split lengthwise into 3 thinner blades (more or less) on one occasion. Again, it depends on the steel. Oil quenched steels are very likely to crack if left too long but air quenched steels probably wouldn't. Thin blades are probably less likely than thick ones. O1 can be used at full hardness (not as a knife though) but S3V can't and so on ....


__________________

Your question may already have been answered - try the Search button first!






Reply With Quote
  #4  
Old 06-02-2013, 07:24 PM
WynnKnives's Avatar
WynnKnives WynnKnives is offline
Steel Addict
 
Join Date: Apr 2012
Location: Wooster, Ohio
Posts: 242
That's what it was, I knew it was something obvious I just couldn't remember. Sometimes the most important things are forgotten and quenching a chunk of steel that is close to 2000, is probably the most stress that a blade will ever see.
Reply With Quote
  #5  
Old 06-03-2013, 06:53 AM
Crex's Avatar
Crex Crex is offline
Moderator
 
Join Date: Sep 2002
Location: Acworth, GA and/or Hanging Dog, NC
Posts: 3,583
As Ray replied all kinds of things to consider that might effect the quenched blade, geometry, composition, carbon content, etc. If you don't know for sure why chance it? Plan ahead and have your tempering oven up to heat and ready. Out fit it with a timer/cutoff so you don't have to babysit. If you don't have time for the number of tempering cycles you think you need or prefer, at least get the initial first cycle done. Then you won't find out the hard way that you shouldn't have waited. Pretty much a no brainer in my book.
Some steels will fool you. You wouldn't think some of them would be all that picky but other factors (above) come into play. Thicker blades with substantial curves, for example. The thicker section may feel reasonably cool to the touch but is still stabilizing and "moving" internally while the edge is set. This can cause micro cracking along the edge due to changing stress factors and with steels you wouldn't expect. Did a himalayn farm knife out of 5160, stalled on the tempering cycle for a day (everyone "knows" 5160 isn't prone to cracking), didn't really check it closely and finished out the blade later ....... two 1/16" micro cracks right along the working curve showed up in the final etching. "Aw crap" moment for sure.
Bottom line, you lose nothing by planning ahead and just doing it.


__________________
Carl Rechsteiner, Bladesmith
Georgia Custom Knifemakers Guild, Charter Member
Knifemakers Guild, voting member
Registered Master Artist - GA Council for the Arts
C Rex Custom Knives

Blade Show Table 6-H
Reply With Quote
  #6  
Old 06-03-2013, 03:45 PM
JawJacker's Avatar
JawJacker JawJacker is offline
Steel Addict
 
Join Date: Sep 2012
Location: Georgetown, DE
Posts: 139
Well the only thing that may help me is, this was the blade I had to re- HT after the the decarb to hot deal, I'll just continue to final grind and see what it looks like. Thanks lesson learned.
Reply With Quote
  #7  
Old 06-03-2013, 05:25 PM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,612
One thing that you could do if you are short on time to do a full tempering of the blade is to stick it in the oven for an hour at about 350? to relieve the stress then do a full tempering when you have the time.

Doug


__________________
If you're not making mistakes then you're not trying hard enough
Reply With Quote
  #8  
Old 06-03-2013, 06:21 PM
Don Robinson's Avatar
Don Robinson Don Robinson is offline
Hall of Famer
 
Join Date: Jan 2003
Location: Brownsville, Texas
Posts: 4,873
Quote:
Originally Posted by Doug Lester View Post
One thing that you could do if you are short on time to do a full tempering of the blade is to stick it in the oven for an hour at about 350? to relieve the stress then do a full tempering when you have the time.

Doug
This is what I always do while my one and only electric furnace cools down enough to temper. I soak it in the kitchen oven at 350 for 2 hours. I usually cryo treat it overnight next, then temper the next day.
Reply With Quote
  #9  
Old 06-03-2013, 09:04 PM
piggy's Avatar
piggy piggy is offline
Steel Addict
 
Join Date: Oct 2012
Location: AZ, Like to party in Tombstone
Posts: 127
I am trying to understand this too. I read that the steel should stay slightly warm between HT and tempering. I also read to wash the knife off then I read not to but to wipe it off as best you can. If the knife is cooled all the way down is this where the risk of cracks become an issue? So is washing it bad?

Sorry JawJacker, this seems to go together so I didn't want to start a new thread.
Reply With Quote
  #10  
Old 06-03-2013, 09:13 PM
JawJacker's Avatar
JawJacker JawJacker is offline
Steel Addict
 
Join Date: Sep 2012
Location: Georgetown, DE
Posts: 139
The way I read it is, as soon as you can hold it, wipe all you can get off with a rag while its warm, throw it in the oven to temper.
Reply With Quote
  #11  
Old 06-03-2013, 09:33 PM
Ray Rogers's Avatar
Ray Rogers Ray Rogers is offline
Founding Member / Moderator
 
Join Date: Jun 2002
Location: Wauconda, WA
Posts: 9,840
What Jaw said. I wouldn't wash it. Most of the literature says the blade should cool to about 100 degrees or a little higher. That's just cool enough to be able to handle it without it feeling uncomfortably hot...


__________________

Your question may already have been answered - try the Search button first!






Reply With Quote
  #12  
Old 06-03-2013, 10:56 PM
Doug Lester Doug Lester is offline
Hall of Famer
 
Join Date: Sep 2006
Location: Decatur, IL
Posts: 2,612
I usually scrub the oil off with a wire brush, detergent and hot water. Don't be too quick to get the blade into the tempering oven or you will risk it not cooling low enough to finish converting to martensite. Wait until it's cool enough to handle with your bare hands.

Doug


__________________
If you're not making mistakes then you're not trying hard enough

Last edited by Doug Lester; 06-03-2013 at 10:58 PM.
Reply With Quote
  #13  
Old 06-04-2013, 05:36 AM
Crex's Avatar
Crex Crex is offline
Moderator
 
Join Date: Sep 2002
Location: Acworth, GA and/or Hanging Dog, NC
Posts: 3,583
Easy rule of thumb.....about the same heat as hot water from your tap (around 110 to 120). Ergo, clean with hot soapy water if you plan to stick in the wife's oven (and like sleeping inside). One of those soap holding pot scrubbers works really well and fast. They have a scotchbrite scrubber built in.


__________________
Carl Rechsteiner, Bladesmith
Georgia Custom Knifemakers Guild, Charter Member
Knifemakers Guild, voting member
Registered Master Artist - GA Council for the Arts
C Rex Custom Knives

Blade Show Table 6-H
Reply With Quote
Reply

Tags
5160, art, bee, blade, blades, easy, edge, etching, handle, heat, hot, knife, made, make, quenched, stabilizing, steel, temper, throw


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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 On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Temper after Heat Treat Question Aaron Banger Heat Treating and Metallurgy 5 02-20-2010 10:38 PM
Temper Question ? SKIVIE The Newbies Arena 4 04-25-2004 05:15 PM
temper Jeff Sorensen High-Performance Blades 4 11-30-2003 12:53 PM
Temper,Temper ,Temper,temper,Temper Gouge The Outpost 28 05-23-2003 09:10 PM
Do I have to temper? aslink The Newbies Arena 3 10-28-2002 01:39 PM


All times are GMT -5. The time now is 07:57 AM.




KNIFENETWORK.COM
Copyright © 2000
? CKK Industries, Inc. ? All Rights Reserved
Powered by ...

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
The Knife Network : All Rights Reserved