Steels for forging.

K

Karoo

Joined
Jan 26, 2017
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I am about to venture into knife-forging, having graduated from stock removal.
Regarding steel choice, it is often said "stick to commercial, well-known steel and leave the unknown."
However, I live in a rural area and have little access to commercial steel. I do, however, have lots of old iron lying around, such as leaf springs from old vehicles (even animal drawn) and mower blades, not to mention files and rasps.
Secondly, I would get more of a kick out of forging a knife from such steel, as opposed to bought steel.
Question: Is there anything to indicate whether or not the above steel is adequate?
Advice is appreciated.
 
You can learn how to spark test the steel to get an idea of how much carbon it has. It won't tell you much more than that, and it takes experience to know what you are seeing. Using some known steel as a guide/comparison to what type sparks are made is a good idea.

Mower blades are almost surely not knife steel.
Leaf springs from old vehicles will work, but the exact alloy will be unknown. Most folks treat them as if thy were 5160.
Old springs from wagons and buggies are often 1075 to 1090 … and make good knives.
Axles from old buggies are often 1070.
Hay rake dumps and the old spiral type harrow rakes are good - 1070 to 1090. They are really good because they are already a reasonable size.
Old coil springs are usually 1090 - 1095.
Old files are usually in the 1090 to W2 range. Farriers rasps may be good, but some were case hardened.

None of the above is a guarantee, though. You can have fun with forging these steels, but get a blade with a poor edge or one that won't harden sufficiently.
No one who can post on this forum is in a place so remote that can't get good steel. If you have internet, you almost surely have mail. Every knife steel supplier will ship steel to you.
Aldo, at New Jersey Steel Baron, USA Knifemakers, JANTZ, Texas Knife Supply, etc. I suggest buying some 1084 or 1075 and learn how to forge blades from that. Then when you start using your found steel you will have an idea how it is supposed to work.

Most important of all - HAVE FUN!
 
I get the allure of repurposing materials on hand.
As Stacy said you can start by looking at spark tests. After that you need to forge some coupons(just shape several pieces down to say 2”x1”x1/8”) and heat treat them to test for harden ability then snap them and observe the grain structure.
 
Thanks Stacey and 3Fifty for the advice.
A clarification is that the mower blade I am referring to is really a tractor-drawn slasher for alfalfa, etc., and not a lawn mower. The blade looks to be similar to leaf spring and nice and thick.
I live in South Africa and yes, I could order off the internet for local steel, but then it is not too far removed from stock removal, I think.
 
Keep doing some google searches. I remember seeing a list of different tools and the typical steels they were made of in an older issue of the Hot Iron News (the newsletter of the NWBA, the archives which are all on their website). This list is over 20 yrs old, and things most likely have changed since then, but it might be a good starting point.
 
Forging w1 or silver steel drill rod,which most engineer suppliers have or a version of,is nothing like stock removal I can tell you :D
Karoo said:
Thanks Stacey and 3Fifty for the advice.
A clarification is that the mower blade I am referring to is really a tractor-drawn slasher for alfalfa, etc., and not a lawn mower. The blade looks to be similar to leaf spring and nice and thick.
I live in South Africa and yes, I could order off the internet for local steel, but then it is not too far removed from stock removal, I think.
Click to expand...
 
There must be some industrial or farm suppliers that will sell high carbon drill rod in South Africa. Here in Canada, we have Ackland’s Grainger, Fastenal, and a few others selling carbon steel. W1 and O1 seem to be most common, with some supply of 1085 or 1095 spring steel, typically in small wire or shim stock.
 
Another way to find good steel would be to contact the purchasing agent at a machine shop in your country. I would think they would oblige you with their sources.
 
John mc c said:
Forging w1 or silver steel drill rod,which most engineer suppliers have or a version of,is nothing like stock removal I can tell you :D
Click to expand...
I take your point.
Thanks for the tips, All. I will go into it, but still look forward to forging with old steel that has been lying about the ranch since my great-grandfather's day.
 
As to the mower blades:
As a general rule, mower blades are made from tough steel. They don't require, and often don't want, hard steel. Lower carbon alloys are normally used. You can find out what steel the blades are made of by going on the manufacturers site and seeing what the alloy is. If it can't be found that way, a phone call to the distributor, or tech services for the manufacturer will give you the exact alloy. You want at least 60 points of carbon to make a knife from it.
 
I like the idea of forging out of vintage steel for authenticity. Especially good steel from 1800s or even from samurai swords 1000 years old. There is a beauty in it.

Having just started to forge knives myself, I can see how laborious a process it is. It takes 2 hours to make a knife to shape as opposed to what I can do in 10 minutes with stock removal. If I have precision ground 1/8" stock already, forging really has no role. It's just for fun. The advantage of forging is that I can do a hammer finished look and make integrated handles onto the knives.
 
Not all mower blades are created equal. John Deere advertises their blades as made from automotive spring steel. Don’t know if they have John Deere in that part of the world though. I’ve used John Deere blades with good results, but I’ve also tried other general mower blades and not had suitable results with any other brand.

Bigger blades like bush hog blades are also different animals. I’ve had success with these blades. I’ve found people calling them 5160, but unlike John Deere I haven’t found official documentation to say so. They heat treated well though. I like to forge a piece thin and test quench in water and try breaking then try quenching in oil and try breaking to get a feel for hardenability. The problem with big bush hog blades is I’ve run into a lot of stress fractures in the steel from their hard life.
 
cotdt said:
I like the idea of forging out of vintage steel for authenticity. Especially good steel from 1800s or even from samurai swords 1000 years old. There is a beauty in it.

Having just started to forge knives myself, I can see how laborious a process it is. It takes 2 hours to make a knife to shape as opposed to what I can do in 10 minutes with stock removal. If I have precision ground 1/8" stock already, forging really has no role. It's just for fun. The advantage of forging is that I can do a hammer finished look and make integrated handles onto the knives.
Click to expand...
1/8” stock is not meant for forging. If you are starting with that stock, yes you are better cutting down to shape. The value of forging beyond it being fun (which it is) is that you can “grow” the steel up to shape. Stock removal requires the shape (including any curves/bends) to all fit within the starting bar, and you must waste steel if you have lots of shaping. A 1/4” thick 6”x1.5” bar can be drawn and forged to be a 1/8” thick chef knife with an 8” blade over 2” tall at the heel with a full tang handle. You need a starting piece with some thickness so you can draw things out how you want (and not have it just want to fold up when forging the profile preform).
 
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