52100

Carbon = 1.00
Manganese = 0.35
Chromium = 1.50
Silicon = 0.25

This is just a reference, refer to the source/vendor for exact chemistry.

52100 is a bearing steel but it makes excellent knives. Proper heat treatment calls for accurate temp. control.

Heat treat;
1. Heat to 1475-1550 and soak for 5-15 min.. Lower temps. require longer soak times and higher temps. need less soak time.
2. Quench.
3. Temper twice for 2 hours each time. Temper between 325 & 450 depending on the application.

The above is just a starting point. You may need to adjust times and temps. to suit your equipment & needs.
I will add that Aldo's 52100 needs to be Normalized in order to fully harden. The following is what works for me and my equipment.

1. Heat to 1650, soak for 10 min., & air cool to black.
2. Heat to 1550, soak for 10 min., & air cool to black.
3. Heat to 1450, soak for 10 min., & air cool to black.

This refines the grain and the steel is now ready to harden.

Again, this is what works for me and my equipment. You may need to adjust times and temps. to suit your equipment.
 

Shane Wink

Well-Known Member
I do the same for Aldos 52100 and foil the blades when normalizing to prevent decarb. I believe it was Kevin that worked that out and that 1650 was needed to unlock the carbides to allow 66-67Rc. Parks AAA for the quenchant.

52100 has been referred to as the poormans O1. All in all I enjoy the lower price an would have a tough time telling the differance between the two in a blind cutting test. I also like the added Cr as it does keep the blade from rusting while looking at it!

The fine carbides that are capable really make for a wicked fine edge.
 
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kamikazej

Gold Membership
At what point would you put the steel in the oven ? Would you wait tell the oven came up to temp or would you put it in before hand ?
 

gnique

Member
Darrin: Your instruction set was quite clear and understandable and I believe that I have a very vague understanding of what the normalization process is. But if 52100 has about the same carbon content as O1, should not O1 be normalized in a similar way? I see a lot written about how very much 52100 needs to be normalized to allow it to achieve its full potential and nothing about O1. It seems to me that equal amounts of carbon would require an equal amount of normalization. I know that this thread is not about O1 and I don't in any way mean to redirect it. Thank you. Nicholas Jasper
 
Any steel in the annealed form will benefit from Normalization heats and thermal cycling to refine the grain. The reason it is so necessary with Aldo's 52100 is that it is highly Spheroidized, which means the carbon is all balled up in big balls for lack of a better explanation. Normalization and thermal cycling are necessary to refine the grain. So its not about the amount of carbon but how the carbon is distributed.
 

Shane Wink

Well-Known Member
Darrin if I am wrong please set my post straight but I understand the multiple cycles used for Aldo's 52100 inpart to having started at 1650 and to shrink the carbides that were released into solution at the higher temp. The Higher starting temp ,1650, Allows more carbides to be dissolved into solution or your hardness will be 63 or less but going that high is not needed because O1 already has enough free carbides in its spheroidal state.
 

Dan Pierson

Well-Known Member
I've got four blades (two chef, two smaller) of this 52100 profiled and drilled but not
beveled. Is there any reason that I can't wrap them together in one piece of foil for
the temp cycling? If so, should I extend the soak times a little, say to 15 minutes?
 

Mike Martinez

Well-Known Member
I've got four blades (two chef, two smaller) of this 52100 profiled and drilled but not
beveled. Is there any reason that I can't wrap them together in one piece of foil for
the temp cycling? If so, should I extend the soak times a little, say to 15 minutes?
I've been doing as such and have not seen any issues. Just make sure you also take into account that they will come down to black heat slower.
 

quint

Active Member
Ive been using basically this same process in my forge with aldo's 521 and have had excellent results. My temps are not as refined but basically the same idea. I quench in warm canola oil though. I only use it for this steel. I have been getting 66-67HRC pre temper repeatedly. Have had great results tempering at 400F for 2 2 hour blocks bringing it down to about 61-61hrc for thin little slicers and kitchen style blades.
 

scott.livesey

Dealer - Purveyor
does anyone have any idea what hardness the bearing manufacturers use? did a rebuild at the office and the bearing race was hard enough that it mushroomed and chipped my H13 punch(Rc50 or so)
the old sailor
 

quint

Active Member
Scott I read up a little and it looks like minimum accepted hardness for bearing components is 58HRC and are generally in the 60 to 64HRC which was listed as the optimum hardness for E52100
 

FORGE

Active Member
I forged a San Mai blade out of 416SS and 52100. I have made about 20 of these and never had a problem.
I heat treated it 1500 Deg F and tempered at 400 Deg F.
Everything was fine, I looked at the blade two days later and everything was fine on the 3rd day I decided to finish the blade.
When I picked the blade up the handle had split on the end about 2 inch back. The 416 did not spit from the 52100, but the 52100 spit right in half.
Has anyone ever seen this happen or can offer an explanation as to why it would happen ?

SPLIT HANDLE.jpg
 

Jon Buescher

Well-Known Member
I forged a San Mai blade out of 416SS and 52100. I have made about 20 of these and never had a problem.
I heat treated it 1500 Deg F and tempered at 400 Deg F.
Everything was fine, I looked at the blade two days later and everything was fine on the 3rd day I decided to finish the blade.
When I picked the blade up the handle had split on the end about 2 inch back. The 416 did not spit from the 52100, but the 52100 spit right in half.
Has anyone ever seen this happen or can offer an explanation as to why it would happen ?

View attachment 70875
I had this happen with 1084 and mild steel on a wrapped eye tomahawk build, I posted pics somewhere but it looks nearly Identical to what you show here
 
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