Bar stock 1095 Warping

bike4fun919 OpbunchKnives

bike4fun919 OpbunchKnives

Knifemaker / Craftsman / Service Provider
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May 5, 2014
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Recently I’ve had two pieces of 1095 flat bar stock ~3/16” thickness. warp. After profiling the blade warped during grinding. I was able to bend most of the warp out before heat treating. The warp came back after quenching. Clamping right after quenching didn’t remove the warp. I tempered the blade and on the second temper used clamps to straighten the bade. It worked some what and I felt I could grind most of the warp out. During the finish grind the blade warped again.
Any thoughts or ideas why this is happening. Makes me not want to use any more of the 1095 I have on hand.
 
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Can't say why you are seeing that on your current 1095, but I started seeing it on 15n20, 1084, aebl, and spicy white (not all from the same supplier).
I expect it from used 15n20, aebl and spicy white but not from the xx84 and have not seen it in 1095 personally.
After reading several threads here regarding warping, I have started ht'ing before grinding and using quenching plates after ht. No more warps (as yet).
Hope you get it sorted out, it is aggravating and time consuming.
 
Normalize and stress relieve the steel prior to heat treat. That will solve 90% of the issues with simple carbon steels. That is assuming the grinds are even, belts were not super dull etc, as those issues need to be corrected first.
 
Grinds are even and new belts so that isn’t the issue.
I will normalize the next 1095 I do but per the supplier it should be good to go.
Thanks !
 
DanF said:
Can't say why you are seeing that on your current 1095, but I started seeing it on 15n20, 1084, aebl, and spicy white (not all from the same supplier).
I expect it from used 15n20, aebl and spicy white but not from the xx84 and have not seen it in 1095 personally.
After reading several threads here regarding warping, I have started ht'ing before grinding and using quenching plates after ht. No more warps (as yet).
Hope you get it sorted out, it is aggravating and time consuming.
Click to expand...
Thanks! I see stress relieving in my future;).
I used to do that when I first started out but the general consensus was for flat stock removal it shouldn’t be necessary.
 
bike4fun919 said:
Grinds are even and new belts so that isn’t the issue.
I will normalize the next 1095 I do but per the supplier it should be good to go.
Thanks !
Click to expand...

It’s not about steel condition, but about relieving the stress introduced when grinding the steel. Usually a sub critical anneal is good, but with some stubborn steels, normalizing is extra insurance.
 
Willie71 said:
It’s not about steel condition, but about relieving the stress introduced when grinding the steel. Usually a sub critical anneal is good, but with some stubborn steels, normalizing is extra insurance.
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Good advise. Rather spend time up front being proactive than loosing time when things don't go as planned.
 
bike4fun919 said:
Grinds are even and new belts so that isn’t the issue.
I will normalize the next 1095 I do but per the supplier it should be good to go.
Thanks !
Click to expand...
I don t say that not even grind is reason of wrap in your case ..but look this pictures .It is hardened HSS steel cut from circular saw...flat as it can be .......After precisely measurement I found why blade bend to right .I need to grind lot of steel here .....and blade will correct itself .
PtcZCB1.jpg

jSeHDAC.jpg
 
I am a little confused by this thread. The OP, i think, was talking about warping while grinding (before HT) as well as after HT, whereas some responses focused only on warping while heat treating (and normalizing to avoid that). Natlek shows an example of warping while grinding (not sure if before or after HT?). I am not sure if the take away here is to normalize but NOT harden prior to HT? I have been considering trying grinding before HT (to see how well belts last) especially for planned high rockwell heat treats) ... so this is really pertinent to me right now...
 
Cushing H. said:
I am a little confused by this thread. The OP, i think, was talking about warping while grinding (before HT) as well as after HT, whereas some responses focused only on warping while heat treating (and normalizing to avoid that). Natlek shows an example of warping while grinding (not sure if before or after HT?). I am not sure if the take away here is to normalize but NOT harden prior to HT? I have been considering trying grinding before HT (to see how well belts last) especially for planned high rockwell heat treats) ... so this is really pertinent to me right now...
Click to expand...

avoiding warping prior to heat treat is mostly about using sharp belts. Dull belts peen the steel, as well as cut, and generate heat, causing the warp.
 
Willie71 said:
It’s not about steel condition, but about relieving the stress introduced when grinding the steel. Usually a sub critical anneal is good, but with some stubborn steels, normalizing is extra insurance.
Click to expand...
Steel is always in tension , even after 2 x 2 hours temper .....how much depend from HT process ....most likely :)
Look in this picture, on left is unknown bearing on right is Japan made one . Both are cut with 1mm.thick cutting disk .
BViuFsD.jpg
 
Thanks for all the responses. Just to be clear I used new belts and kept the steel dipped between passes so the blade did not get overly hot. This was a thick blade and I wanted to do some pre-grinding prior to heat treat. The blade warped and I straightened it before I did the heat treating. The blade showed warping after heat treating - I clamped immediately after heat treating. During the second temper I straightened the blade again. The blade warped during the post heat treat final grinding. I'll accept user cause.
 
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