What kind of steel are needles/safety pins?

[Leon Husock]

Anyone know? I'm thinking of making some canister damascus and I'd rather not have to then make a san mai out of it if I can avoid it. I know some of them are nickel-plated, but I imagine the plating is thin enough not to be too much of a concern.

 

[Stacy E. Apelt - Bladesmith]

Generally, sewing needles are some simple high carbon steel. Figure them as something between 1080 and 1095. Sewing needles are hardened.

Sewing pins are usually a softer steel. They may, or may not, harden fully, but would probably provide a pattern in the damascus. Sewing pins are usually not hardened.

Safety pins are usually similar to swing needles in being a simple carbon steel. Figure them between 1050 and 1080. Safety pins are usually hardened to some degree.

 

[Leon Husock]

Generally, sewing needles are some simple high carbon steel. Figure them as something between 1080 and 1095. Sewing needles are hardened.

Sewing pins are usually a softer steel. They may, or may not, harden fully, but would probably provide a pattern in the damascus. Sewing pins are usually not hardened.

Safety pins are usually similar to swing needles in being a simple carbon steel. Figure them between 1050 and 1080. Safety pins are usually hardened to some degree.

Great, thanks! Unfortunately it seems like it's hard to buy bulk quantities of sewing needles cheaply in the way I'd need for a canister weld, plus I already have a bunch of pins and safety pins. Maybe I'll do some break/spark tests on them both and see how they go. Thanks again, Stacy.

 

[Stacy E. Apelt - Bladesmith]

Simplest test would be to heat them in the oven to 1500F and then drop in a pan of oil. If they hardened, and break when bent, they will be fine.
Even if they are lower in carbon, there will be some increase in hardenability due to carbon diffusion/migration from the powder to the pins.

I see sewing needles on ebay for $1 for ma 30 pack of assorted sizes from China. They usually will gove a big discount for a bulk order. Ask them what 25 packs would cost.
Sewing machine needles are also on ebay in bulk packs of 100.

Tandy used to sell bulk packs of large sewing needles for leatherwork.

 

[Leon Husock]

Even if they are lower in carbon, there will be some increase in hardenability due to carbon diffusion/migration from the powder to the pins.

Unfortunately I'm hoping to use nickel-plated pins for that halo of silver effect that you get on nickel-plated stuff, and from what I understand nickel will inhibit the carbon diffusion. I just tried to do a break test with the pins I already have and they bent but didn't break, so it looks like anything I made with those will need a HC bit in it. I'll look into sewing machine needles, thanks.

 

[Stacy E. Apelt - Bladesmith]

The nickel plating won't probably stop anything. It is only a few microns thick.
Nickel sheet in thickness of a few thousandths will make a bright stripe in damascus, but I doubt there will be any visual effect from plating around pins.