Steels?

Keith Montgomery

Keith Montgomery

Joined
May 9, 2000
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When reading another thread a question came to me that I realized that I don't know enough about a certain area of forging. I was wondering if I could get some help.

There are many different steels that can be used for a forged blade. What are the good and bad points in regards to the use of these different steels? Which steels are prone to warping? Which one are hard to work? Which are the most forgiving? Which ones will tend to crack more easily if hammered when the steel has cooled a little below the proper working temperature?

What are the reasons that you don't see A-2 or S-7 used very much for forging? Why do I not see the W steels used as much as 10 series or 5160 or 52100?

Lot's of questions here and I do know some of the answers, but I would like to know a lot more about this aspect of forging a blade.

Thanks in advance to all those that wish to help me with answers to my queries
 
Some steels do not like to move much under the hammer, or tend to work harden while forging. This is the case with A2. A2 will work harden if you drill it too fast, so I imagine getting it red and hitting it with a hammer would not be much fun either. Don't know about S7.

As to the W series of steels, I imagine you don't see much more of it being used due to availability. It's getting really hard to find a source of W2, and W1 is not much different than 1095, except a little more carbon.
 
Some Steel's just are not made for Forge work i will grant you they can be Forged just very close on temp's and all so many maker's don't forge them , Take D-2 it can be forged if you are willing to watch the Temp's very closely and Pre warm the Anvil and Hammer face a little , most guy's don't want to be bound to such precise work and 1/2 times you Pound it a little too cold and it can shatter so all of the hard work was in vain . Some Stainless forges well if you can keep it hot enough .:)
 
Keith,
Some very good questions. Here are a few things I've found out in my
shop over the years on a few different steels that I use.

52100 and O1 are prone to crack if you hammer them too cool. However their edge retaining abilities are awesome. They both are good for damascus steel making. 52100 does not move as well as O1 when hammered. It's a little more tough to forge. Glad I have power hammers for this steel.

The W steels and 10 series steels are very forgiving and are NOT prone to cracking when hammered cool. You'd see more use of W2(my first choice with Vanadium content) and W1(no vanadium) if it were more readily available to knifemakers in bar stock. These steels are usually found in round stock from my experience. I just purchased a large amount of W2 and you will be seeing me use this a lot in my future knives. It has 1.03 carbon percent and .22 Vanadium for better edge retention. These are all Very good steels for damascus welding.

5160 and 6150 are very forgiving steels to forge but with the chromium content can air harden and sometimes give problems when draw tempering spines and tangs if it is turned orange in color because it can then air harden. They are both good for damascus welding.

A2 gave me lots of trouble trying to make good clean consistent damascus welds and it's not as forgiving to forge I believe because of its higher chromium content. Makes a good knife when stock removed.

S7 is a good steel for making punches and hammers. It can take a fair amount of impact abuse. I've not tried to make damascus with it. I have forged tomohawks with it and it forges well and is fairly forgiving when hammered cool.

As far as warpage, any blade of any steel can warp when heat treating if ground uneven. A properly normalized blade is less prone to warp during the quench from what I have experienced. I've not noticed one steel over the other to have more warpage characteristics. The thinner the blade the more prone it is goig to be to warp when heat treating.

This is not all carved in stone, it's merely what I have experienced in my shop and I hope this helps a little.
 
One more steel. How could I have left out the major steel I use for contrast in damascus. 15N20. It is a 10 series steel with nickel content. It's basicly 1075 with a few points of nickel percentage. There is no chromium in 15N20 like L6 which is a cousin to 15N20.

15N20 is very forgiving. Makes a good knife all by itself too. I like it so well I have over 6,000 pounds of it right now.
 
Ron, how would W2 and 15N20 be as a damascus mix? Are they too far apart in heat treating specs to work properly?
 
What steel most knife makers usually use it what they learned to use and what is available. The characteristics of the steel will be learned by using and from others that use the same steel. Availability of the steel and its reputation will determine whether it will be of widespread use.
Danbo: It looks like the W steels and the 15N20 would work very well together.

The characteristics of the steel is pretty much as Ron said about working it. I like the 52100 because I get to rest more often between heats. :) The 15N20 band saw blade also makes a good kitchen knife for the wife with very little work. :)
Ron: How thick is the 15N20 you have?
One of the requirements of forging is the ability to normalize and anneal the steel when done forging. Some of the steels that can be forged to shape, are very difficult to anneal so that shoulders can be filed and holes drilled and tapped.
 
Danbo,
W2 and 15N20 is an excellent damascus blend. In fact I am going to veer away from the O1 and 15N20 damascus blend I've been using and go to primarily the W2 and 15N20 mix. Here's why: By eliminating the O1 (which is about the same carbon content as W2) I will not have to spherodize anneal my damascus any more and the W2 is much more forgiving than the O1. I basicly will have the same type performance damascus but will have more freedom in the forging and annealing processes.

One thing that has caused me to walk away from the 1084 steel is the fact that more and more poor quality 1084 bar stock is hitting the market with inclusions in the steel. This has been a long on going problem with 5160 and has now creeped into the 1084. Too bad our Q.C. requirements at the steel mills are not more stringent.

Ray, as far as my 15N20 it varies from .070" to .090". It is all Swedish Udeholm steel.
 
Thanks to all that have posted to this thread so far and a special thanks to Ron for bringing up spherodize annealing. Though I basically knew what this meant, I wanted to know more and so I started looking around the internet for a good explanation. I found quite a few that were more technical than I wanted, but then I came across a great article by Kevin Cashen on swordforum.com. Reading this article gave me a lot better understanding of the heat treating processes.
 
Ron, since you posted your reply I have been taking a look at W-2. It looks very interesting, but how can a maker get consistent results with a steel that can have such a huge variance in carbon content?
 
Keith,

Good question. A short story before I get to the W2 question.

Steel manufacturers in the U.S. are not held to stringent repeatable steel batch analysis standards when making different batches of steel. In the early 80's I worked for Alcoa Aluminum in the Smelting Division and learned that not every batch of metal is identical.

So batch A poured on Monday may have a slightly higher percentage of Carbon than batch B poured on Friday at the mill.

However there is a necessary percentage range(Key Word) of different elements in a steel to make the steel fall into a category called AISI Type O1 tool steel for example. This AISI Type O1 category requires that the steel must have:
Carbon range of .85-1.05%
Manganese 1.00-1.40%
Silicon .15-.40%
Chromium .40-.60%
Tungsten .40-.60%
Vanadium .15-.30%
As long as a manufacturer falls within these percentages he is allowed to call his steel AISI Type O1 Tool Steel.

Having said all that. W2 is no different when it comes to percentage of element requirements. The large quantity of W2 I just purchased came with Chemical Analysis Documentation when the steel was poured in 1998. I have the Manufacturer name, batch number, heat number, trace number, serial number, and of course the chemical makeup of the W2. The amount of Carbon in my W2 is 1.03%. In all of it. Because it all came from the same batch.

I forged a 10" test knife from my new batch of W2, 2 weeks ago and documented my heat treat method and temperatures used to perform my knife tests. The tests were very satisfactory(and even better than my tests on 52100 I might add)

As long as I repeat the same heat treat recipe I can be assured I will get the same performace from several hundred blades that will be made from this W2 batch. If I ever get a new batch of steel which can very well have different percentages of elements, I will need to make a new test knife and see how it performs. If a new batch in the future doesn't get as hard as the old batch I may need to alter draw temperatures.

This is the best way I can explain how I get consistent results from a steel over and over again.
 
Thanks Ron. Actually that explanation makes complete sense.

Another question. I often hear of the W steels being referred to as simple steels. Looking at the chemical composition of these steels, they look like they are anything but simple. They have rather large numbers of alloys, albeit in fairly small amounts. Why do I see these referred to as simple steels? Are these statements in error?
 
Keith,
I've been searching for several years for the origination and coining of the phrase "simple steels" but have not found the accurate origination. There are some text books that give slight mention to simple alloyed steels.

I think "simpler" steels would be more appropriate. You're right that many of the so called simple steels are not so simple. The 10 series and W series steels are simpler when compared to 52100 and O1.
 
I am just amazed that any steel that has: chromium, manganese, molybdenum, nickel, silicon, tungsten and vanadium could be considered a simple steel.

So is W-2 a good choice for a big knife? Say a Bowie with a 12" blade.
 
Keith,
12"? Sure. I've been given orders to pound one out into a 14" blade as my next project. That will be one big bowie. But this guys loves big knives. Who doesn't?
 
Ron, would it be safe to say that basically any of the mid to high range carbon content steels can be made to perform well? I notice alot of variety among top bladesmiths regarding choice of steels. In my short time, I have tested 1084, O1, and 5160. Once I had my draw temps worked out, they all performed well.

I have heard alot about L6 and the W series since 1084 is becoming scarce. Where are you getting the W2? Any thoughts on L6?? Sorry so many questions but this thread sparked alot of interest for me.

Thanks in advance, Brett
 
Anyone ever try the Hitachi carbon steels, like white #1, #2, #3, Shirogami 1, or Blue Super Steel? These seem to very pure and consistent steels. I realize that these steels are not American made and for this reason may not be popular, but some of them seem like they would be great for forging.
 
Brett,
Sure most of the steels used by bladesmiths can be made to perform well. Some steels perform longer between sharpenings and take more abuse.....these are the steels I seek out. I passed my journeymansmith test with 5160 but it is not very high on my list.

To answer your W2 question: I bought out a stock pile of W2 from a warehouse that's had this since 1998.

Keith,
I beleive the steels you mentioned are found in Murray Carter's kitchen knives. He visited my shop a couple years ago and gave my wife a kitchen knife made from one of the white steel series. #1 I believe.


I hear the steels are very pure. I don't doubt it since the Japanese Quality Control Smelting standards are quite stringent.
 
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