Strange discoloration after hand sanding

Looks like auto hamon to me too
Prob left too thick before hardening at that point
Is it a kitchen knife?
Doesn't look to go to edge so should be ok but they do look ugly on a blade
 
John mc c said:
Looks like auto hamon to me too
Prob left too thick before hardening at that point
Is it a kitchen knife?
Doesn't look to go to edge so should be ok but they do look ugly on a blade
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Yes sir. Chef's knife. I did grind bevels pre heat treat but the stock was less than 5/32" thick. It's still 1/4" away from the edge. Hoping it will survive.
 
killthelights said:
Yes sir. Chef's knife. I did grind bevels pre heat treat but the stock was less than 5/32" thick. It's still 1/4" away from the edge. Hoping it will survive.
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1095 needs a really fast quench, parks 50 works best. I’ve quenched full thickness 1/8” stock without issue, but if your thinking of trying a different steel Pops Knife Supply just started carrying 8670 in house, it’s a high nickel carbon steel used for saw blades in industry. It is a very tough steel, about 5 times tougher than 1095 at the same hardness. I’ve experimented with it and done a few knives that I’ve left at 63hrc and it holds a great edge, it’s also a deep hardening steel so you don’t need the fast quench oil and it’s a bit more forgiving on heat treating versus 1095. There stock comes at a very fine grain and is ready to quench without thermal cycling. I hot stamp my makers mark so I thermal cycle anyway and it is easy to get a really fine grain again.
 
Joshua Fisher said:
1095 needs a really fast quench, parks 50 works best. I’ve quenched full thickness 1/8” stock without issue, but if your thinking of trying a different steel Pops Knife Supply just started carrying 8670 in house, it’s a high nickel carbon steel used for saw blades in industry. It is a very tough steel, about 5 times tougher than 1095 at the same hardness. I’ve experimented with it and done a few knives that I’ve left at 63hrc and it holds a great edge, it’s also a deep hardening steel so you don’t need the fast quench oil and it’s a bit more forgiving on heat treating versus 1095. There stock comes at a very fine grain and is ready to quench without thermal cycling. I hot stamp my makers mark so I thermal cycle anyway and it is easy to get a really fine grain again.
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I used Park's 50 and went straight into the oil in less than a second. Who knows. I had already decided I was done using 1095 and based on your suggestion I'll try some 8670. I had read about it somewhere then forgot the steel and where I read about it(I'm going downhill fast haha). I'm pretty sure this was it though. Thanks!
 
killthelights said:
I used Park's 50 and went straight into the oil in less than a second. Who knows. I had already decided I was done using 1095 and based on your suggestion I'll try some 8670. I had read about it somewhere then forgot the steel and where I read about it(I'm going downhill fast haha). I'm pretty sure this was it though. Thanks!
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Fast move from oven to oil is good thing , always . BUT you need to understand what and way is important ............In less than second for 1095 steel .......MEAN that oil must cool down steel to a certain temperature /search that/ in LESS then second , not to move blade from oven to oil in less then second :thumbsup:
 
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Natlek said:
Fast move from oven to oil is good thing , always . BUT you need to understand what and way is important ............In less than second for 1095 steel .......MEAN that oil must cool down steel to a certain temperature /search that/ in LESS then second , not to move blade from oven to oil in less then second :thumbsup:
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Natkek parks 50 is a commercial oil over here that has an initial cooling rate of water so it is fast enough to properly quench 1095 assuming the oil was in its working range of 50-120 degrees Fahrenheit and the blade was left in the oil for atleast 5-6 seconds fully submerged and agitated to ensure a vapor jacket didn’t form. Also it’s important that there was enough oil for the size of the blade. I use 5 gallons of parks 50 and can quench a blade up to 16” long in my current container and there is enough oil to properly cool the material.
 
Is it possible to salvage this blade by re-heat treating it? I've seen a few threads about HT problems where the conclusion seems to be "throw that one away", but I always wonder about that. Why not re-do the normalization and quench and temper processes?

If warping is a concern (because of post-HT beveling), there are ways to try to straighten the blade. If the warp is unfixable, you haven't done that much more work prior to giving up on the blade. And you might salvage it.

None of this is a serious suggested solution by me - I'm far too new at this to have a meaningful opinion. It's more me wondering why I don't see this suggested more often. Maybe there's some good reason why this wouldn't work at all - if so, please let me know.

Thanks,

-Tyson
 
Joshua Fisher said:
Natkek parks 50 is a commercial oil over here that has an initial cooling rate of water so it is fast enough to properly quench 1095 assuming the oil was in its working range of 50-120 degrees Fahrenheit and the blade was left in the oil for atleast 5-6 seconds fully submerged and agitated to ensure a vapor jacket didn’t form. Also it’s important that there was enough oil for the size of the blade. I use 5 gallons of parks 50 and can quench a blade up to 16” long in my current container and there is enough oil to properly cool the material.
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I understand that . Reading his post I was under impression that he mean on moving speed from oven to oil not on oil cooling speed of steel ?

killthelights said:
I used Park's 50 and went straight into the oil in less than a second.
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Joshua Fisher said:
Natkek parks 50 is a commercial oil over here that has an initial cooling rate of water so it is fast enough to properly quench 1095 assuming the oil was in its working range of 50-120 degrees Fahrenheit and the blade was left in the oil for atleast 5-6 seconds fully submerged and agitated to ensure a vapor jacket didn’t form. Also it’s important that there was enough oil for the size of the blade. I use 5 gallons of parks 50 and can quench a blade up to 16” long in my current container and there is enough oil to properly cool the material.
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That last part is interesting. i just have one gallon in a container that's just a little over a gallon. That might be part of it.
 
Tyson A Wright said:
Is it possible to salvage this blade by re-heat treating it? I've seen a few threads about HT problems where the conclusion seems to be "throw that one away", but I always wonder about that. Why not re-do the normalization and quench and temper processes?

If warping is a concern (because of post-HT beveling), there are ways to try to straighten the blade. If the warp is unfixable, you haven't done that much more work prior to giving up on the blade. And you might salvage it.

None of this is a serious suggested solution by me - I'm far too new at this to have a meaningful opinion. It's more me wondering why I don't see this suggested more often. Maybe there's some good reason why this wouldn't work at all - if so, please let me know.

Thanks,

-Tyson
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I don't see why you couldn't but with this particular knife i'll just finish it and use it in my kitchen.
 
Joshua Fisher said:
I believe the OP said he heat treated it in an even heat oven.
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Ah, yeah I see that. It looked like the tang acted as a heat sink, typical of a 2 brick forge heat treatment. Since it was an oven, beats me! Were you able to get the whole knife handle and all in the oil, or just the blade?
 
Did I miss the heat treat this knife went through? Did you soak at target temp after your oven was equalized?
 
Ok this is not uncommon for NJSB. It’s actually quite common. And no it’s not ok, I would email them and have them replace it or refund you. That spot will not harden no mater what you try. Here are a few pictures showing a few of the blades I have come across that had this issue. So don’t feel bad a have a folder full of customers that got bad steel from NJSB, your not the only one.

Photo%20Nov%2006%2C%202%2045%2036%20PM.jpg


Photo%20Dec%2031%2C%209%2007%2041%20PM.jpg


Photo%20Nov%2024%2C%2010%2011%2029%20PM.jpg
 
Don’t get me wrong, I’m not trying to bash NJSB. But I would rather pull my finger nails out then trust any of their 1084-1095 & W2. I do buy from them but I limit it to 80CrV2 as that has not had any of these issues.
 
E.Carlson said:
Ah, yeah I see that. It looked like the tang acted as a heat sink, typical of a 2 brick forge heat treatment. Since it was an oven, beats me! Were you able to get the whole knife handle and all in the oil, or just the blade?
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All of it except between an 1/8" to 1/4" of the tang.
 
Josh Rider said:
Did I miss the heat treat this knife went through? Did you soak at target temp after your oven was equalized?
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Standard heat treat. Using an Evenheat oven I put blade in at 1300 ramp as fast as poss. to 1475, soak 10 min, quench in Parks 50.
 
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