1084 heat treat

Jonnymichigan

Active Member
Hey guys. This is my first non intro post. I am a knife maker from northern Michigan. I do stock removal. I want to find out what everyone's recipe for heat treat on 1084 is. I use aldos 1084. Please include normalizing and Thermo cycles and temper.

thanks guys.

Jon

I normally do 1600/1500/1350 for ten min each and cool to black in the air

then 1485 for ten min and quench in parks 50. Temper 400 degrees for 2 hours x 2

I've also tried just 1375 for ten min for grain reduction as I am not do stock removal then 1485 for ten min and quench in parks 59 the. Temper 400 degrees two hours x2
 

EdCaffreyMS

"The Montana Bladesmith"
Normalize: 1600F, cool in still air to below 900F

Thermal cycle: 3X 1st@1500F, 2nd@1350F, 3rd@1350F. Allow to cool in still air to 900F or less between cycles.

Hardening: 1500F and quench. As quenched, you should see Rc hardness of 64-65. NOTE: 1084 is a shallow hardening steel. It requires a very fast quenchant. Personally I use Parks 50.

Tempering: Temper quickly after hardening to avoid stress risers/cracks. Tempering temps start at 350F, and depending on the knife/uses, may go as high as 450F. The majority of hunter/utility blades that I make of 1084 are tempering in the 375F-425F range I believe it is essential to temper for 2 hours, with 3 cycles, allowing the blade(s) to cool to room temp between cycles. (DO NOT try to cool blades quickly.....let them cool naturally, on something like a baking rack.)

NOTE: I am absolutely opposed to lengthy soak times at or above Austinitizing temps for blades in any step(s) of the process. With certain steel types soaks are necessary during the hardening process, but for the majority of what I would call "Forgable" steels (simple carbon steels, and some alloy steels). I can only guess that all the talk of lengthy soak times at or above austinitizing temps that I see being recommended have come from the mindset of "if some is good....more must be better". Nothing could be further from the truth! LENGTHY SOAK TIMES AT OR ABOVE HARDENING TEMPS CAUSE FAR MORE HARM THAN GOOD.

One final note..... remember that any specific action, that has a given temp associated with it..... the blade must be at that temp when the action occurs! What does that mean? The best example I can give is.... when quenching, you want 1084 to be AT 1500F when it contacts the quench oil. If your quench tank is very far away from your heating source..... and you heat the blade to 1500F....and have to walk 10 feet to the quench tank....the steel will be well below the required temp by the time you get there.
 

Chris Railey

KNIFE MAKER
Ed surely gave good advice above especially about the no lengthy soak times. 1084 does not require that at all. The best advice I can give you is this: Go to Kevin Cashen’s website and order his video guide to 1080/1084. Watch it until you understand exactly why you need to treat 1084 the way he says. I promise you your blades will benefit more for the $35 you spent on the video than any other $35 investment you make.
 

Doug Lester

Well-Known Member
Wait for the "shadow" from decalesence passes while heating and then quench if you don't have a regulated high temperature oven to austenize the blade in. Simple carbon and low alloy steels don't need a long soak. They just need to come up to temperature. If you don't have a high temperature oven to austenize in don't use steels that do need a soak to get the carbon from the carbides into solution. Trying to eyeball a ten minute soak in a forge is asking to overheat the blade and cause grain growth.

Doug
 

Jonnymichigan

Active Member
Hello Jon,

Since you have access to him, run any information you are curious about by Tim Z. and see what he thinks. That would be your best bet.
Of course. I try to do that as much as I can. I'm just seeing what others are doing as well. I do what Tim tells me. I learned that the hard way haha!
 

Jonnymichigan

Active Member
Of course. I try to do that as much as I can. I'm just seeing what others are doing as well. I do what Tim tells me. I learned that the hard way haha!
Also on a side note I seem to text and call him an awful lot I hate to bother him every time I have a question. Which is a lot. Everyday lol
 

Jonnymichigan

Active Member
Normalize: 1600F, cool in still air to below 900F

Thermal cycle: 3X 1st@1500F, 2nd@1350F, 3rd@1350F. Allow to cool in still air to 900F or less between cycles.

Hardening: 1500F and quench. As quenched, you should see Rc hardness of 64-65. NOTE: 1084 is a shallow hardening steel. It requires a very fast quenchant. Personally I use Parks 50.

Tempering: Temper quickly after hardening to avoid stress risers/cracks. Tempering temps start at 350F, and depending on the knife/uses, may go as high as 450F. The majority of hunter/utility blades that I make of 1084 are tempering in the 375F-425F range I believe it is essential to temper for 2 hours, with 3 cycles, allowing the blade(s) to cool to room temp between cycles. (DO NOT try to cool blades quickly.....let them cool naturally, on something like a baking rack.)

NOTE: I am absolutely opposed to lengthy soak times at or above Austinitizing temps for blades in any step(s) of the process. With certain steel types soaks are necessary during the hardening process, but for the majority of what I would call "Forgable" steels (simple carbon steels, and some alloy steels). I can only guess that all the talk of lengthy soak times at or above austinitizing temps that I see being recommended have come from the mindset of "if some is good....more must be better". Nothing could be further from the truth! LENGTHY SOAK TIMES AT OR ABOVE HARDENING TEMPS CAUSE FAR MORE HARM THAN GOOD.

One final note..... remember that any specific action, that has a given temp associated with it..... the blade must be at that temp when the action occurs! What does that mean? The best example I can give is.... when quenching, you want 1084 to be AT 1500F when it contacts the quench oil. If your quench tank is very far away from your heating source..... and you heat the blade to 1500F....and have to walk 10 feet to the quench tank....the steel will be well below the required temp by the time you get there.
Ed are you leaving the blade in for ten min during each of the thermo cycles?
 

EdCaffreyMS

"The Montana Bladesmith"
NO! When you're dealing with simple carbon steels, the only thing that long soaks can do, is cause harm! Unless I specifically state an amount of time, all you do is bring the steel, to the temp, perform whatever the action is, and move on.

I have to ask.....why are you doing a 10mins soak on 1084? Maybe because of the 1485F temp?

I harden at 1500F..... so the blade is brought to 1500F, little to no soak (less than 1 min), and quenched.
 

Kevin R. Cashen

Super Moderator
Jon, like I said, run everything you hear by Tim, see what he says, one day I am sure we will talk as well. The people who have impressed me the most over the years are the ones that double checked even what I said and came away with a full picture. Tim will always back up his opinion with hard data and facts, just as I would, that is VERY important.
 

KenH

Well-Known Member
when quenching, you want 1084 to be AT 1500F when it contacts the quench oil. If your quench tank is very far away from your heating source..... and you heat the blade to 1500F....and have to walk 10 feet to the quench tank....the steel will be well below the required temp by the time you get there.
Ed, that is a GREAT comment, and one I had not really considered when HT'ing metals. Even with the quench tank right there at the oven the blade is going to drop temperature a bit, you can see the color of the blade changing as it's removed from oven, then turn, and put in oil. I suspect that's why I've found it to work better when I use a tad (25°F?) higher temp for HT'ing. That's simply giving the blade a change to actually have the required temp when it hits the oil (or quench plates).

I LOVE IT when Ed or Kevin comment - and there are other very knowledgeable folks here also.

Ken H>
 

EdCaffreyMS

"The Montana Bladesmith"
I came about that from trying to help others with with their heat treating issues. You'd be surprised at how many people have their forge/heat source on one end of the shop/work place, and the quench tank on the other end. The first time I it realized this might be a trend, was helping a young fella who was not getting the hardness he was expecting when quenching. We went over and over his process on the phone, and all at once it dawned on me to ask..... "Where is your quench tank in relationship to your forge?"...... his response was "Oh....about 15 feet away." DING! We figured it out. Since then when someone requests help with their processes. one of the first things we talk about is where things in their shop are located, in relationship to other things. :) Thanks for catching onto that Ken.
 

Jonnymichigan

Active Member
NO! When you're dealing with simple carbon steels, the only thing that long soaks can do, is cause harm! Unless I specifically state an amount of time, all you do is bring the steel, to the temp, perform whatever the action is, and move on.

I have to ask.....why are you doing a 10mins soak on 1084? Maybe because of the 1485F temp?

I harden at 1500F..... so the blade is brought to 1500F, little to no soak (less than 1 min), and quenched.
I do it cause a known maker is my mentor and I was just trying to see why other people do to compare my notes
 

Jonnymichigan

Active Member
I came about that from trying to help others with with their heat treating issues. You'd be surprised at how many people have their forge/heat source on one end of the shop/work place, and the quench tank on the other end. The first time I it realized this might be a trend, was helping a young fella who was not getting the hardness he was expecting when quenching. We went over and over his process on the phone, and all at once it dawned on me to ask..... "Where is your quench tank in relationship to your forge?"...... his response was "Oh....about 15 feet away." DING! We figured it out. Since then when someone requests help with their processes. one of the first things we talk about is where things in their shop are located, in relationship to other things. :) Thanks for catching onto that Ken.
Mine is right in front of my kiln
 
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