Tips on choosing steel thickness for a san mai

[FatFrumos]

Hello. When picking steel thickness for san mai, is there some sort of golden ratio of core material thickness to jacket thickness that people adhere to? If we look at it as left jacket > core > right jacket, is it 1>1>1 or .5>1>.5 or something else? I'm planning to use it for a kitchen knife, if it makes a difference.

Thank you!
Luka

 

[HSC ///]

I like the 1:1:1

 

[FatFrumos]

I like the 1:1:1

Thank you!

 

[Richard338]

You can think about it in terms of the look you want. I bought some with a relatively thin core. After grinding, that places the transition very close to the edge. That might be what you want with a stainless jacket, but I was hoping for more like the look that HSC achieves with the transition higher up the bevel.

 

[HSC ///]

You can think about it in terms of the look you want. I bought some with a relatively thin core. After grinding, that places the transition very close to the edge. That might be what you want with a stainless jacket, but I was hoping for more like the look that HSC achieves with the transition higher up the bevel.

Just FYI, When the transition is higher up on my bevels it’s actually not desirable for me, it’s not what I prefer or want.

 

[Richard338]

Just FYI, When the transition is higher up on my bevels it’s actually not desirable for me, it’s not what I prefer or want.

Understood. I did stock removal, so the result was a straight transition very close to the edge. It made sense once I thought about the geometry, but I guess I had visions of a more interesting look.

 

[Natlek]

Hello. When picking steel thickness for san mai, is there some sort of golden ratio of core material thickness to jacket thickness that people adhere to? If we look at it as left jacket > core > right jacket, is it 1>1>1 or .5>1>.5 or something else? I'm planning to use it for a kitchen knife, if it makes a difference.

Thank you!
Luka

on first picture san mai is 1,2mm +1.5mm +1.2 mm
final thickness 3,7 mm

other one

 

[FatFrumos]

Thanks, that's very helpful.

 

[weo]

It depends on both the look you want for the final blade and the method of getting there.
For examle: If you are planning on forgewelding the billet yourself and if you haven't forged many blades, I'd suggest starting wirh a 2-1-2 because you'll probably go(burn/grind) through a lot of the outer layer.
Basically, the more forging you do, the more of the steel you wil lose to scale and oxidation, and this is from the surface.

 

[tiguy7]

This William Henry B-15 Titan looks to be 1:1:1.View attachment 1887866View attachment 1887865

 

[DevinT]

The percentage thickness of the core to the overall thickness will be the percentage of the core showing from the edge to the height of the grind.

2:1:2 = 1/5 or 20% = 20% of the core showing from the edge to the top of the grind.

1:1:1 = 1/3 or 33% = 33% of the core showing from the edge to the top of the grind.

The math works if you look at it. Some things like edge thickness, type of grind, material loss etc. will affect it some so slight adjustments should be made.

Hoss

 

[Richard338]

The percentage thickness of the core to the overall thickness will be the percentage of the core showing from the edge to the height of the grind.

2:1:2 = 1/5 or 20% = 20% of the core showing from the edge to the top of the grind.

1:1:1 = 1/3 or 33% = 33% of the core showing from the edge to the top of the grind.

The math works if you look at it. Some things like edge thickness, type of grind, material loss etc. will affect it some so slight adjustments should be made.

Hoss

Yep, I just checked the math and for a FFG you scored 100%. That's a good way to think of it and a nice starting point if you consider other grinds.