Best source for 52100?

NickWheeler

NickWheeler

Joined
Dec 3, 1999
Messages
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Okay, I'm convinced that I've got to try 52100 as I'm moving from stock removal to forging.

I just got some round-stock from Admiral, any comments on the quality of what they carry?

I know Ed has mentioned moving from bearings to big round-stock, but where do you get it? With a press I'm sure I can knock it down ;)

Ed, in Knife Talk you mentioned Rick Dunkerley comparing a stock removal blade to his 52100 forged blade after the Oregon show at Wayne's... And later on that steels that out-cut the 52100 snapped like glass in the bend test. Which steels were they? 440-V, 3-V??? Very curious.

As sort of a side note here, I just wanted to say that Ed's book is a great read. It's the little things I've picked up reading it in the last 3 days that make me very glad I bought it. It's not only easy to read, it's fun to read.

Oh, and Ed, be sure that I'll have some triple quenched/tempered 52100 blades to get your opinion on this spring at the Oregon show. :D Even if I wasn't interested in the performance end of things (which I am) Rick showed me a photo of a 52100/stag hunter while we were bs'ing behind the tables at the MKA show this year, he said it was one of his favorite fixed blades he'd done...and man was it pretty!

Thanks!
Nick
 
Hello Nick: thanks for the kind thoughts about my book, they are appreciated. I have been working on and with 52100 for a long time, it is a very beautuful steel to work with. Things that you need to get along with your 52100 steel are a chemistry and a cleanliness statement. Also date of manufacture are important issues. You want to work with steel that you can get more of the same lot of, if it works out. The steel is very honest, and if you are working with steel from the same lot very consistent. There is an emence amount of information and research written about it. I have been buying mine from Rex Walter and very pleased with it. Rex Advertises in the classified sectioin of Blade.
We are dreaming about a custom lot of 52100 steel for knives. Should this come to pass, big things could be in the future. I don't have any practical experience with the many sources of 52100. I would gluess that many of them are good.

I worked with used ball bearings for over 10 years and learned a lot that is very helpful with this new steel. If you can work down a 5 1/2 inch bar of round stock, you have a great potential for good times and high performance knives. The whole trick is to work the steel down at low temp. 1625f is my upper limit. Grain won't grow below 1725 so the 1625 provides an adequate safety margin. I just heard about an outfit working 52100 at 1450f with good results. My article in Knives 2002 discusses the sugject in depth.

I am working on my 52100 cookbook that will have all the information I know included. Working with Rex has provided the scientific view to explain what I always figured was happening. New steel is absolutely better than old used stock. Your decision to use new steel is a very wise decision.

I bleieve that the larger the stock you start with the greater your potential to achieve higher levels of performance.

I warn you, the quest for high performace is addicting. The cost of your steel is insignificant when compared to the time you will devote to pushing it to the upper limit. The trick is to do nothing to detract from the potential of the steel.
 
As to the streels I have comparison tested to 52100, I would rather not mention them by name. I will say that the steel compared to was the best cutting stuff I have ever tested. It was a horse race neck and neck for cut. The comparison steel was very hard to shaprpen, taking over 15 minutes to sharpen, the 52100 was ready for another test in less than a minute on a fine India stone. Toughness was another story. I have probably easily doubled the cuttiing performance of 52100 since that test.
Don't know what their improvements consist of. We have achieved #14 and finer grain in 52100.
 
Ed, Thanks for posting such valuable info here for us. Would you tell more about grain sizes. You have achieved #14 grain size? Ive never heard that before, please expand on this subject. It is probally in the new cook book but I cant wait.
 
Bruce and all,
Grain size in steel is measured much the same as sand paper is rated i.e. so many grains per inch. Grain size in steel is rated by, x in one one hundredth of a square inch, (.o1 square inches.) when the system was divised fine grained steel had five to six grains per .01 square inches. Industry standard for fine grained steel is now six to eight grains per. .01, with very fine grained steel having 12 grains per .01.
Recent tests have shown that the knives that Ed and I make have a grain size of six to eight on the spine progressing to >14 in the cutting edge. In the exact words of Rex Walter, " we need to develop a better measuring system to measure the smaller grains in you guys' knives". Ed may wish to add to this post but that is my understanding of what we are achieving in our 52100 blades.

Bill B.????
 
Bill explained the subject of grain size very well. Achieving it comes from low temp thermal cycles and mechanical reduction. A 20 point reduction by forging provides top steel for industry. The best they can afford or wish to pay for. The blade smith who whises to push the window can go much further. From a 6 inch round bar we have the opportunity to achieve up to a 279 point reduction in the cutting edge and probably more than that. This sets the table for a well tuned heat treat to take the steel to its maximum performance potential providing we do nothing to detract from that potential. It means tending your steel very carefully, planning every hammer blow. Work it right and you can go into heat treat with a #10 grain. That is where the afterburners kick in and WOW! Unfortunatelty we have found no shortcuts, all take time, but it is time well spent.
 
Hi,
Have you noticed any difference in performance between hammering out round stock and taking it down to billet size with a press prior to hammer forging the blade? I am not as young as I used to be...Ken

PS: Get Ed Fowler's book. It is one of the few where you can see art with technology instead of art versus technology.
 
Hello Simmonsk; thank you for the kind words concerning my book, they are greatly appreciated. I have never used a press so can't compare, I believe that the performance develops with the number of thermal cycles as well as mechanical reduction. From a theoritical perspective I would suggest that if you used a press and worked it down slowly, a little at a time, and try to maintain somewhere around 20 low temp thermal cycles you could very well get there from here. I use flat dies to allow me to work the steel as much as possible. There has been a lot of debate on the subject, but I know of no emperical data. Good Luck
Take Care
 
Ed,

You mentioned forging at 1625 degrees. Do you now have a pyrometer on/in your forge? And are you still using the Mankel I saw in your video?

Ed and All,

I have used a Mankel but always have problems with hot spots and with having to heat up an entire blade to work on any one part of it. What sort of forges are others out there using and what is the best way to get one to run at a specific and known temperature, 1625 for example?

Thanks,

John
 
Hi John: I use an older version of the Mankel 3 burner forge. I installed valves on each burner to enable me to adjust them individually. It takes time, but you can get the job done. Then I insulated the inside of my forge with K wool and finally coated the k wool with some stuff the Bill Burke found that really made a difference. Once you have reached the operating temperature of your forge, take the time to reduce the overall volume of gas into the forge. It does not take much gas pressure 3 to 4 pounds on my pressure gauge. Then adjust air and individual burners until you get what you want. Glass blowers are the real professionals at adjusting gas forges, watch one next time you get a chance.

The 1625 f temperature is easily recognised by the formation of very fine to none scale on the blade when you take it out of the forge and start working it. If the scale is much heavier than snow flake material you may be too hot. If the scale is comming off in thick sheets you are definately too hot. I found the forging temp by watching scale and verified it with an optical pyrometer. Low temp forging takes more time, but with good steel it really pays off. To my knowledge there is no other knife steel with the data behind it like 52100. Reams of research available at you local lybrary.

Sometimes it is necessary to cool a part of the blade while forging another area, usually the tip gets too hot. I have my quench tank filled with Texaco Teyp A next to the forge. It doesn't hurt a thing to cool the blade between forging cycles, in fact it helps refine the grain. Just a 5 second quence will do the trick if you plan your forging sequences right.
 
Have any of you guys tried the Japanese forging technique of brushing water on the anvil and soaking the hammer head in a water bucket between heats with 52100? I guess that might throw off the ability to watch the scale size since it blows it off so hard...

I was reading about the quick quenches while forging to shape...will vet-grade mineral oil work or do you think it has to be Texaco quench oil?

Thanks! :)
Nick
 
Hello again Nick: I have not tried the water stuff, I like to keep track of the nature of the scale. With low temp there is not much scale.

Texaco type A is made to fine tuned specifications. You can purchase any oil as long is it is equivalent to Texaco Type A. Conoco and Moble also have it available in smaller quantities. If the Vet grate is the heavy grade it would work, otherewise may be too fast or slow?
 
Chevron also makes a type a equivelent. that's what I use. Ive tried the water thing and got some crackes in the blades. I haven't done any testing to find out why. the "stuff" that I put on Eds' forge was ITC 100 and then ITC 256. I am not positive about the last number but it was the stuff that was made to go over the top of the ITC 100 as a finish coat. When Ed says the size of snow flakes I believe that he means the little "wyoming" type snow flakes that blow all over and not the big heavy wet flakes.:D

Bill B????
 
Bill :

Grain size in steel is rated by, x in one one hundredth of a square inch, (.o1 square inches.)
Click to expand...

This defines the density but not the size. How large are the actual carbides? For reference iron carbide in tempered martensite is between 0.1 and 1 micron (its not spherical, more like chains). The larger alloy carbides, especially in highly segregated steels can be up to 50 microns. Due to the low segregation in the CPM steels, even with high alloy contents they can keep the carbide size down to 2-6 microns.

-Cliff
 
Hello Cliff: The measurement stuff comes from our man in the laboratory, Rex Walter. If you want to see the grain size, there is a photomicrograph in Knives 2002, page 56.
Take Care
 
Grain Size is measured several ways. The most common way is to count the number of grains per a given unit at x magnification.
I don't have my ASTM reference material handy but , I seem to recall that a grain size of 12 is about 2.5 microns.
Ed and Bill B, I left a copy of this spec. with you when I was out in Aug. I will not be able to access mine at work until monday.
Take care
Rex
 
Thanks for the info, I just order a copy of Knives 2002, I am sure it will make interesting reading.

-Cliff
 
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