Steel for a corkscrew

[lyuv]

I forged my first corkscrew (wine bottle opener). On my first attempt to penetrate a cork, the "screw" got twisted.  

Made it from an unknown mild steel (probably equivalent to A36). The screw had a 3.0-3.3mm wire.

Is this normal that mild steel  is too soft for a corkscrew? If you use hardenable steel, do you harden it?

[JustAnotherViking]

Yes - too soft

No - doesn't need to be heat treated

[Koek]

I made one from mild steel but shaped it like a medieval auger (a twisted strip), works well but you need to sharpen the tip like you sharpen a drillbit. 

[Zeroclick]

I used mild and it is holding up ok but then I made it quite short and a bit thicker.

I have used it a fair bit and had no problems, but I agree with JustAnotherViking, if you want a finer cork screw use a higher carbon steel.

[ThomasPowers]

I'm betting that the "doesn't need to be heat treated" means leave it normalized---which is a heat treat, letting it cool from critical temperature in air.

[Will W.]

And why not just harden it and temper it to blue? If youre going to buy high carbon steel, use the carbon! Lol. 

[JustAnotherViking]

Without a proper tempering oven, I'd say that would be quite difficult to do? 

Given the torque a corkscrew can be under, I don't think hardened would be wise. You'd want a bit of spring in it, so air annealed plays it safe? 

It was Mark Aspery who said it didn't need heat treated in one of his videos, so I'd take it as good advice. 

[Will W.]

It wouldnt be too bad, just hit it with a torch or hold it over your forge until its blue. Do that twice and it would be pretty hard to break it.

But i dont make corkscrews, so im just speculating. 

[Frosty]

A toaster oven will do a fine job of tempering a cork screw. It's not like a high impact tool or a pry bar. Just draw it down to purple say if it's a middle high carbon steel like 5160 and it'll be good.

Frosty The Lucky.

[Ranchmanben]

I use coil spring and let it normalize. Doesn’t take long once drawn out. 

[JustAnotherViking]

Not high impact, but under quite a bit of force. 200 - 400 newtons when pulling the cork out of the neck.

[Steve Sells]

16 hours ago, JustAnotherViking said:

Without a proper tempering oven, I'd say that would be quite difficult to do?

where did you get that idea ?  read the Heat Treat stickys for more info

[JustAnotherViking]

I assumed that taking it up to a blue (over 500f) would be tricky enough without loosing the hardness to the point it was worth doing in the first place?

i.e. hard to stop the temper at that point by flame, and ovens don't tend to get hot enough?

I shall go and read.

[Steve Sells]

that is only 260 C

[JustAnotherViking]

Is that not right around the tempered martensite embrittlement realm? (please excuse my ignorance, genuine question)... I was (most likely incorrectly) under the impression that once you go that far, it's borderline needing to be heat treated again because it's quite easy to dip past the point of no return at those temperatures, hence the comment about a controlled heat treatment oven rather than eyeballing it by color? (I suppose a lot depends on the alloy in question also)

[Frosty]

Reality check time here guys. 200-400 Newtons? Martensite embrittlement . . . realm?

This is a cork screw, if you're not sure draw the temper down farther. I've never known spring steel to be particularly brittle drawn to purple but that's just me and I can't eat even 200 Newtons at once, a box lasts me a week at least. Sorry, couldn't help it. Yeah I know what a Newton is but I couldn't resist, it's a Curmudgeon thing.

You're not building space craft, painting the Mona Lisa, or such. Heck it's not even a Claymore just a cork screw.

Blacksmithing is about estimations, approximations and eyeball measurement, NOT lab equipment. If we were measuring to that scale the smith would be sitting in an air conditioned control room, wearing a suit and tie, monitoring comp screens and sipping a Jolt Cola. 

Frosty The Lucky.

[BIGGUNDOCTOR]

JOLT, there is a name I have not heard in awhile. And I prefer the original Newtons.

For a corkscrew I might use a straightened out valve spring. Heat to critical , quench, then draw to a purple. As to stopping the color running - a bucket of water works great.

[TwistedCustoms]

Garage door coil springs are nice for smaller projects that require more carbon. They make short work of screwdrivers and such because the diameter is pretty much there to begin with. If you harden your cork screw and draw it to blue it should hold up. Make a test piece and after you temper it screw it into a piece of balsa wood or soft white pine, really give it a workout. Once you're satisfied that you wont brake it give it a go on your favorite Cabernet!

PS If you forge a tapered square lug on the handle end (like a brace bit) and punch a square hole in a forged, ornamental handle you can join the two pieces with a little peening and have a T handle model without much sweat. If you have suitable material to make a cork screw, ie spring steel, then you also have what you need to make some square punches if you don't already have a bunch!

[Will W.]

1 hour ago, Frosty said:

I can't eat even 200 Newtons at once, a box lasts me a week at least.

Were all thinking it, and Frosty just says it .

Seriously though, its just a corkscrew. If your going to use hardenable steel, seems to me you might as well harden it and temper according to its intended use. Otherwise, why waste the metal that makes good blades/tools etc? When you could just use mild. 

[anvil]

Frosty,,, you are outrageous !!! And right on the money!  A big thumbs up!