San mai on small rolling mill

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Natlek

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What do you think about that ? Welding two steel together is more about right temperature not pressure ? I m talking about making one piece of san mai steel , just for one knife at time ? Say core steel 1.5mm and from side say 0.5 , 1 , 1.2 mm........ stainless . This is jewelry rolling mill but just looking at that thing I think that could be good for this ? They can be find cheap enough so I don t think that is worth wasting time to make one ....and they look very ,very solid ?
@ Stacy E. Apelt-BladeSmith must have one of this :)
 
The rollers will suck the heat out of the billet too fast for it to weld. The rolling mills that do welding are hydraulic controlled with lots of pressure and are power driven to run the steel through fast. They are about 30 times heavier than a sheet/wire rolling mill. I have several 300 pound plus rolling mills that are powered by 1HP motors and gear reduction chain drives. They have pretty heavy (6" rollers) ... they roll sheet and wire for jewelry just fine ... but they won't roll damascus.
 
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I think a while back there was an video posted on here of a rolling mill that someone made for damascus. It was FAST!

The billet went through the press and back out in under a second, if I remember right... It's definitely not a small, jewelers type mill, it's specialist equipment for sure!!
 
Stacy E. Apelt - Bladesmith said:
The rollers will suck the heat out of the billet too fast for it to weld. The rolling mills that do welding are hydraulic controlled with lots of pressure and are power driven to run the steel through fast. They are about 30 times heavier than a sheet/wire rolling mill. I have several 300 pound plus rolling mills that are powered by 1HP motors and gear reduction chain drives. They have pretty heavy (6" rollers) ... they roll sheet and wire for jewelry just fine ... but they won't roll damascus.
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Watch this Stacy and @ A.McPherson ...this don t look that heavy build and lot of pressure used ?

 
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Stacy E. Apelt - Bladesmith said:
The rollers will suck the heat out of the billet too fast for it to weld. The rolling mills that do welding are hydraulic controlled with lots of pressure and are power driven to run the steel through fast. They are about 30 times heavier than a sheet/wire rolling mill. I have several 300 pound plus rolling mills that are powered by 1HP motors and gear reduction chain drives. They have pretty heavy (6" rollers) ... they roll sheet and wire for jewelry just fine ... but they won't roll damascus.
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I don t want to roll damascus Stacy .Just to weld three piece steel together .Not to thin them from one inch thick to 1/8 inch ....? Why should be there lots of hydraulic pressure ? Size/Dia. of rollers , distance between them and thickness of passing steel dictate how much pressure will go on hot steel ? Why should we need hydraulic here ?
Al I want is to laminate steel ,nothing more ?
 
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Just weld it by hand. As you say, it is a very simple process.

Or, get that mill and roll all the san-mai you wish. Let us know how it works.
I have two powered mills and at least three hand crank mills that I could sell to the san-mai guys.
 
Tracy, Why the difference in a rolling mill for San Mai vs Damascus just for setting the weld? Both require setting the weld before any drawing out is done. It's my understanding it doesn't take that much pressure to set the weld, I've read about using a manual vise to clamp and set the weld. Drawing out would take much more pressure would be my thinking. Would either of your presses draw out San Mai? OR, just set the weld?

Natlek, from the videos above there is no way to tell how much pressure is being used. There is an hydraulic ram below that's pushing the bottom roller up and that could be LOTS of pressure, or a small amount. Looking at the frame of either rolling mill it looks like they are built much like a hydraulic press and able to hold LOTS of pressure.
 
Both of those appear to be McDonald rolling mills with foot pedal actuation. (You can see the guy's knee in the first video on the right kicking down the pedal) They're not developing huge tonnage.

I think the problem with setting welds in a rolling mill is likely going to be too much deformation causing delamination on the end not currently in the roll. With a full perimeter MIG weld around the seams, that may be prevented. Otherwise it's no different than trying to set welds in a hydraulic press with round drawing dies. You can to it, but it's a lot harder than with nice big flat dies and even pressure.

Drawing evenly once welded, to thicknesses very hard to accomplish with a press, seems to be a rolling mills biggest usefulness.
 
kuraki said:
Drawing evenly once welded, to thicknesses very hard to accomplish with a press,
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Interesting comment - I did not realize a press was not good for drawing out a billet. Is that why folks have both power hammer and a press? I've never used a press, nor even seen a press used in real. I've only seen a power hammer and used it for a few strokes on a billet so I know NOTHING about using either.
 
Ken H> said:
I did not realize a press was not good for drawing out a billet.
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(Feel free to correct me here, John.) I don't think John's saying that a press isn't good for drawing out a billet, but rather that it's harder to get a specific thickness on a press than a rolling mill (which is what these are designed for, if I'm not mistaken).

In my experience, a power hammer (adequately sized, of course) will be able to draw out a billet much faster than a press. But it's easier for me to get a uniform thickness under a press than a power hammer, because it's slower. My mentor, who has 30+ years of using his #300 Chambersburg, is just as accurate with his hammer as I am with a press, and he's a lot faster.
 
Yes, those look like McDonald rolling mills. IIRC, they run the billet through FAST. Pressure is pretty high due to mechanical advantage. The designer came up with a good safety feature that has the billet come out of the mill toward the billet holder. This prevents the chance of tongs or handles getting pulled into the rollers. It also means you can roll the billet with a handle welded on ( or not have to let go of the tongs).

As to rolling to set the weld, you may create a problem by the fact that no matter how light the squeeze is, the billet will be elongating. The force isn't straight down, but is longitudinal to some degree. This may shear the weld as it makes it.

Once the billet is welded solid by hand or press, the rolling mill will be able to elongate the hot metal without shearing the weld.

Some of the advantages of a rolling mill in drawing out the billet (after welding) are:
Rollers are totally directional. The strip gets longer, but not wider.
The thickness is exactly the same throughout the billet.
There is a much smoother surface.
Rollers can be patterned to create ladder and other patterns.


I find a press the simplest method of setting the welds.

Natlek's questions have me thinking about changing the gear ratio on one of the rolling mills and seeing how it works for drawing billets with the speed increased.
 
Stacy E. Apelt - Bladesmith said:
Just weld it by hand. As you say, it is a very simple process.

Or, get that mill and roll all the san-mai you wish. Let us know how it works.
I have two powered mills and at least three hand crank mills that I could sell to the san-mai guys.
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It s indeed simple process .Maybe two years ago I do that . 3.5mm 15n20 in middle and two 3mm 52100 from side . Perimeter weld , heated to welding temperature and in my vise....works on first try .It laying somewhere in my shop , it is about 4 inch long and about inch and half wide .....clean and temperature is two major factor for success..I don t waste my time hanging on bladeforum , you can learn are lot :)
Now , I have hydraulic press /50 T home made/ right outside of my shop , but is it hand operated ......and work only in one way..down .
I doubt that you talk from personal experience about this topic .....You should know that it is not easy to work on cold silver .In that video that small press is move silver easy .I don t think that to weld san mai i need that much pressure so i THINK that this jewelry press should work .I don t intend to make hundreds ...just one now another one maybe next summer , I do this for fun don t forget that .You say that the rollers will suck the heat out of the billet too fast ? How ? Did you try that so you know ? I don t think so ...sorry ! Contact between rollers and steel is very small at first and steel MOVE ......And because of that small contact surface pressure on steel is high ,depend on opening of rollers and dimension/thickness of steel which goes between them ....
Look , I have make roll press for my service more then 30 years ago , but it has three rollers because i use it for work on leaf springs ............
I like this idea of rolling mill because it is quiet , i live in very urban environment .
What i want to do is this ..................1.5 or 1.8 mm 1.2519 steel as core and 1mm stainless on sides .....to get something like this on picture ,clean line between steel and even/centered core thickness when you look in spine so that s why I think mill is right tool ?
l5tz1RB.jpg

I found another video......leaf spring

 
Yeah, I have no experience rolling metal beyond the 40+ years I have done it. I roll mokume, silver, and gold regularly. As I said, I have multiple rolling mills. I have used a press many times to weld a bilet up. You control the "bite" by the foot pedal.Press just enough to set the weld. The speed of a knifemaking press is usually about 1.5IPS. Slower will work, but the loos in weld time is a lot. I can weld up a 6X2X2" billet in one heat on a press.

But do your own thing. Have fun doing it and post your results.

I'm gone.
 
When I write that I doubt that you talk from personal experience about this topic I mean on using one of your jewelry press to weld sanmai steel .Maybe I should ask that as a question to you ....
Once again , I don t want to make it longer , not wider or thinner. I want to weld it with minimal change in dimension ...if it is possible .
 
Well, the whole rolling mill sounds great at first. In fact, I'd be surprised if some of the laminates out there aren't made on a rolling mill. But I'd bet those rolling mills won't fit in your average work shop. Kuraki and Stacy are correct. The weld would be constantly sheared as the core elongated entering the roll and the jacket elongated directly in the center of the roll.
 
Stacy E. Apelt - Bladesmith said:
You clearly don't understand how a rolling mill works.
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Of course that I understand how rolling mill works Stacy .........that is reason why I open this thread to ask if that would be possible ...but we start to arguing about other things irrelevant to subject . My idea was this ............ knowing that there is no need to very high pressure , force to weld two metal , my thinking is to try something like this ....say IF steel thickness is 4mm , set rollers opening say on 3.9mm so almost no deformation on steel , or very little ? Just enough pressure to weld steel .....Bullet welded all around perimeter of course , maybe some spot weld in middle to help keep pieces together ... Moving rollers slow maybe would help , to . I hope that someone was tried this and that is way I ask here ....

http://www.yourarticlelibrary.com/m...als-process-and-principles-with-diagram/95556
The material is fed in between two rollers, called working rolls, that rotate in opposite directions. The gap between the two rolls is less than the thickness of the starting material, which causes it to deform. The decrease in material thickness causes the material to elongate.
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In rolling, the metal is plastically deformed by passing it between rollers rotating in opposite direction. The main objective of rolling is to decrease the thickness of the metal. Ordinarily, there is negligible increase in width, so that the decrease in thickness results in an increase in length.
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tkroenlein said:
Well, the whole rolling mill sounds great at first. In fact, I'd be surprised if some of the laminates out there aren't made on a rolling mill. But I'd bet those rolling mills won't fit in your average work shop. Kuraki and Stacy are correct. The weld would be constantly sheared as the core elongated entering the roll and the jacket elongated directly in the center of the roll.
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I don t know............... what is happening when we rolling steel is this ......the material is pushed in the reverse , towards thick side ,BLUE arrow on picture ? Welding is happening outside of rollers/ and between rollers pass already welded steel ??? How that can shear/ delaminated weld ? Why I think that pressure is just in right place to weld ? I m just loud thinking .....
XKWWK4e.png

One more note .I think that jewelry roll mill is better for this because both rollers are driven by motor or handle whatever is ....that must make difference ?
 
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