San mai by hand

Josh Rider

Josh Rider

Stuff maker
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Sep 2, 2014
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I've been thinking about trying some San mai without a power hammer or press. I've been making knives stock removal for a few years, but almost no forging experience. I started gathering wrought, but am reading that this has a high failure rate with my experience level. With forging temps for wrought being so high and all.

Would something like 15n20/1084 or 15n20/W2 be better to start off with?

I don't mind difficult, I just figure if I can increase my odds starting out, that would be more motivating.
 
Have you thought of mild steel/1084 to start? I did a few pieces last year, and found the nickel in 15n20 prevented some of the carbon migration effect we like to see. I used thinner stock, and got some bad welds/inclusions. If I did it by hand again, I'd go 1/4" 1084 and 3/16" mild on the sides. Heat the anvil to minimize the parasitic loss. Once welded, forge to shape.

Others with more experience can correct me as needed.
 
I get mine from metalsuperstores. It's 1018. Home hardware/lowes might be a36. A36 is recycled steel with unknown composition.
 
Willie71 said:
I get mine from metalsuperstores. It's 1018. Home hardware/lowes might be a36. A36 is recycled steel with unknown composition.
Click to expand...
A36 is a structural grade steel that is certified to a standard. Most hot roll steels are tested before and after rolling. It is often mis quoted as regular hot roll. 80% of steel produced in North America is made from recycled materials including 1018, ar400, 1144, 4140. They test the material while it in the ladle and add what chemicals are need to get the grade of steel they want.
 
203e looks really good too. I was thinking about getting some 1008 plate and cutting it into strips.

There's a Japanese super clean mild steel, but I can't justify the expense yet.
 
1"X6" pieces of 203-E and 1084 would be simple and fairly easy to weld up. Use the standard 1/4" 203E ( it is hard to find another size) and 1/8" core of 1084. By the time you weld it up and forge/draw it down into a flat knife size billet, it will be somewhere around .20". Forge the blade from that. The 203E will not harden so the blade will be extremely tough. Yu can HT the 1084 for a higher hardness than normal, since breakage isn't an issue., but also has 2% nickel, so it stays pretty bright.

1018 would also work fine.

After you get a few of those billets done, try 15N20 and 1084.
 
Thanks for the suggestions, I hadn't thought about mild steel.
I'll try that first then.
 
Dry welding, never had a failure with this method. As long as the pieces are clean before you MIG weld them together, it's hard to not get a good weld if you have enough heat. The advantage is that you don't ANY flux with this method. Yes, I weld all of mine in one of my Atlas mini forges, 20 PSI, with just a hammer and anvil.
 
Hello all. Been awhile.
Any thoughts on O1/15N20?
(Hope I'm not hijacking the thread...)

~billyO
 
Tyshoots said:
A36 is a structural grade steel that is certified to a standard. Most hot roll steels are tested before and after rolling. It is often mis quoted as regular hot roll. 80% of steel produced in North America is made from recycled materials including 1018, ar400, 1144, 4140. They test the material while it in the ladle and add what chemicals are need to get the grade of steel they want.
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A few years back, Ed Caffrey told me that he stopped using A36 for fittings, etc because he etched a piece and could actually see the faint shadow of a machine screw. ;)
 
O1 is a good steel but at forge welding temps it can get a tad tricky as it wastes to come apart and crumble. I destroyed a few bamascus Billets that way when forging welding in a O1 core. With all the great steels like 52100,15n20,1084,1095,W2,5160,a203e,304,316 exc I don't think it's worth messing with O1. Don't much care for the steel my self.
 
jdm61 said:
A few years back, Ed Caffrey told me that he stopped using A36 for fittings, etc because he etched a piece and could actually see the faint shadow of a machine screw. ;)
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It was probably junk hot roll material. Somehow A36 started being used as a term for all hot roll material. I'm not saying it could not happen but the chances of it being A36 are pretty slim. Everytime you drive over a bridge or see a large steel building it's made with A36 material, or A572 Grade 50. They are often duel certified at the Mill.
I am pretty new to knife making, but steel is what I do for my real job.
I plan on making it up to Ed's shop sometime soon and I'll make sure to talk to him about that.;)
 
I have read that account in the past and dismissed it. If people knew how a melt was done and the amazing amount of rolling reduction done to the original billet from the melt, it would be clear how impossible it is to have intact screws show up. Maybe Ed saw something that reminded him of machine screws, but it was not actual machine screws. I have always chalked this story up to an urban myth.
 
jdm61 said:
A few years back, Ed Caffrey told me that he stopped using A36 for fittings, etc because he etched a piece and could actually see the faint shadow of a machine screw. ;)
Click to expand...

So, this is something that bothered me for a while because I've seen you reference it a few times, and being that we consume about 2000 tons of A36 a year at work I thought it was a bit ridiculous, but...

qZNgtyH.jpg


This is some Grade 70 ASTM certified plate, that bolts either fell out of the roll mill or some other equipment and rode the plate through the rollers. They weren't forge welded in, but instead just imprinted the material. I could see how if this plate was drawn down further yet, something like the above could happen.

I know it's an old thread but I thought this a relevant update to have some photographic proof of heat tracked, certified plate with something similar to what was described.

A36 is not "36 different types of steel in a pot" or "made from nuts and bolts" or whatever nonsense, but now I have an example of how someone might be lead to believe it is.
 
That type inclusion is often misstated as being in the melt. It is almost always from something getting on the billet as it is rolled out to size starting at about 36" thick.It is still not a good thing, but not often from something in the melt crucible.

The fact that they are on the surface and clustered together supports the after melt scenario.
 
Starting to stray off topic, but a number of years back, one of my best friends who's been a blacksmith for about 40 years, had a couple of ball bearings come out of a piece of 1" square that he was forging under his 300# Chambersburg, ruining the piece.
~billyO
 
Josh, have you tried any laminated steel yet?
you may want to make your own for fun or whatever reason, but you could try out a bar of laminated steel for $40 or less.
the experience might further encourage you or the opposite :-)
 
HSC /// said:
Josh, have you tried any laminated steel yet?
you may want to make your own for fun or whatever reason, but you could try out a bar of laminated steel for $40 or less.
the experience might further encourage you or the opposite :)
Click to expand...

No I haven’t. That may be the route I go though since I haven’t been able to forge since a cervical surgery I had recently.
 
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