17-4 Ph and 17-7 Ph Stainless Steel for Armour

[Craig Nadler]

The only company that I could find that has MIG wire for 17-7ph is Washington Alloy. The quote that I got from one of their dealers is:

17/7 PH .030” 30# spool: $87.12/# - $2613.60.
17/7 PH .030” 10”# spool: $88.45/# - $884.50

Anyone know of any other sources. It looks like I may be able to get a 2 pound spool seeing as it still meets the minimum order size.

[Craig Nadler]

I found another dealer who would sell me the same 10 pound spool for $450 or the 30 pound spool for $1200. The 2nd dealer said that the material is mil-spec certified, that is why it costs so much.

[Baron Alcyoneus]

Have you tried cutting off a "stick" and using it for welding rod?

[Craig Nadler]

This is MIG wire not TIG rod. In general it is far easier to get speciality alloys in TIG rod then MIG wire.

[Scott Martin]

Hi Craig

at those price points I'd look at what a TIG welder would cost - same inert shielding gas, better welds and no issues about getting specialty wire (use thin strips of scrap as filler instead)

A decent TIG is in the ~$1500 range which isn't a whole lot of MIG wire at those prices.

That said, I'm not planning on doing much welded construction with the 17-7: currently working on a pair of gauntlets to see how much more durable they are than the 304 series I prototyped most recently. If 18 Ga 17-7 work hardened is suitably tough I may stop there, or look at 20-22 Ga with a 1050 heat treat. if this isn't tough enough then I will look at heat treating the 18 Ga.

Scott Martin

[Craig Nadler]

I just finished this pair of mid to late 14th century spaulders made from 0.035"/20ga./0.9mm 17-7ph stainless steel heat treated to a TH1050 condition. IMO, the dent resistance of the heat treated 17-7ph stainless steel is at least as good as 0.090"/13ga./2.3mm 304 stainless steel.

[Scott Martin]

I can believe that - I have started a pair of gauntlets using 0.050" (18 Ga) 17-7PH in annealed condition, and my normal method to cut out the complex arts of the plates is to use a jewelers saw. I used about a dozen blades on the last gauntlet (made from 304 and 430 stainless)

The 17-7 is INSANELY tough - I wear out a saw blade in less than 1" of cutting, so for the primary mitten plates I have used almost two dozen blades already, and will use a similar number AGAIN when I trim these plates to articulate smoothly, and this doesn't count the blades that I will need to use on the wrist assembly - which I am considering making out of 304 now!

I will again note that this is ANNEALED - hardened I anticipate that the teeth of my saw blades would just slide off. On the plus side, once polished, this material should be very hard to scratch.

Craig, have you done any hot working, or has this all been cold? if I'm fluting this, I anticipate that I may need to work it hot, and the orange range is "touchy" - I need to repeat my experiment and see what heat range makes it "bubble". I also need to work harden a piece to failure, and evaluate whether this is likely to be a concern. I do tend to clean up edges on stainless to a polished finish, which significantly reduces the tendency to crack, but this may be less of an issue on the 17-7

Neat stuff, I'll be grabbing a bit more today!

Scott Martin

[Craig Nadler]

Scott Martin:

I have not tried to hot work 17-7ph yet. I don't really do much hot working to begin with.

I dished a pair of 0.050"/18ga./1.3mm knee cops and a pair of 0.048"/18ga./1.3mm knee cops. There wasn't a huge difference in the amount of effort needed.

I'd like to try making a helmet out of 0.090"/13ga/2.3mm 17-7ph, but nothing seems to be selling lately. Between the spool of 17-7ph MIG wire and a 0.090"x36"x48" sheet of 17-7ph I'm looking at $700+ in materials.

One major benefit of heat treated 17-7ph stainless steel over 1050 or even 410 stainless steel is that if you screw up the heat treating on 17-7ph it realistically can't end up too hard, It will just be softer than you wanted.

[Caius705]

What style helm would you make?

[Craig Nadler]

A Sugarloaf or Visored Sugarloaf would be fairly safe choices. I could also make a Klapp visor basinet like this one: http://nadler.us/klapp_visor_bascinet.html . I did have the thought that I might make another one of the close helmets seen here: http://nadler.us/close.html . The visor with the vertical bars was for a type of 16th century foot combat tournament. For ACL/BotN I would need to add 2 or 3 horizontal bars welded on to the backside of the vertical bars. I'm thinking that I would blackened the horizontal bars to make them less noticeable.

[Caius705]

Out of curiosity, what price would you be looking at for a klappvisor done in 13 gauge 17-7 steel?

[Craig Nadler]

After thinking about it a while I'm going to stay away from the Klappvisor basinet as a first 17-7ph helmet. If anyone is interested in Sugarloaf or Visor Sugarloaf then please PM me seeing as this is not the Classifieds Forum.

[Craig Nadler]

More 17-7ph stainless steel armour. This is a early 15th century Italian style right pauldron made from 0.035"/20ga./0.9mm 17-7ph stainless steel heat treated to a TH1050 condition.

[Craig Nadler]

Blackened heat treated 0.035"/20ga./0.9mm 17-7ph stainless steel rondel.

[Baron Alcyoneus]

How did you blacken it?

[Craig Nadler]

I used Sculpt Nouveau Stainless Black:

http://www.sculptnouveau.com/Details.cf ... category=6

[Craig Nadler]

I received the sheet of 0.091"/13ga./2.3mmx36"x48" 17-7ph stainless steel that I ordered. I cut out the blank for half of a helmet top. Even with a B-3 beverly shear it was a real pain to cut, in this aspect it seemed to me to be similar to 0.109"/12ga./2.8nmm 304 stainless steel. I started dishing it and a very rough guess is that it takes the same amount of force to shape as 0.109"/12ga./2.8mm 304 stainless steel. When compared to 0.090"/13ga/2.3mm 1050 carbon steel the 17-7ph steel is much harder to work.

When I finish dishing the test piece I'll post another report.

[Craig Nadler]

I'm going to order a 10 pound spool of 0.030" 17-7ph stainless steel MIG wire. If I order 1 spool the price is $350 + shipping, for 3 spools the price per spool is $250 + shipping. This is by far the best price that I've been able to find. Anyone interested in buying one of these spools.

The source is: http://www.weldtool.com/

[Craig Nadler]

I just welded together my first 17-7ph stainless steel helm top. The metal thickness was 0.090"/13ga./2.3mm. This one will be used for destructive testing after it has been heat treated. The amount of force needed to shape the 0.090"/13ga./2.3mm 17-7ph stainless steel helmet halves seemed to be comparable to the force needed to shape 0.109"/12ga./ 2.8mm 304 stainless steel. Halfway though the shaping process the helmet halves work hardened to the point that they need to be annealed (1950F/1066C) in order to make any further progress.

The welder used was a Lincoln SP-170 MIG welder, amperage for the outside pass was set to 140. The shielding gas used was 98% argon and 2% oxygen. My initial plan was to see if the weld could be done in a single pass from the outside and without using a copper backing plate for the weld area.

The first thing that I noticed was that while welding the metal the weld did not pool very well and it seemed like the weld didn't penetrate as well as with 304 stainless steel. An inside weld pass was needed. I set the amperage to 170 for the inside pass had no problems with burn through on the weld. IMHO the spec. sheets for 17-7ph stainless steel were correct that it is difficult to weld. I think that with a copper backing plate for the weld area and the amperage set the 170 you maybe able to weld 0.090" 17-7ph stainless steel helmet halves in a single pass from the outside, but unless the helmet halves for perfectly butted together IMHO it is easier to use an outside and an inside pass.

Please note that it would be a good idea to re-annealed the helmet top and any parts that are welded on to it before the heat treating process. The reason for this is so that the final hardness after the heat treating is consistent.

[Baron Alcyoneus]

Did you use 17-7 wire for the weld? That is incredibly expensive.

[Craig Nadler]

Yes, I used 0.030" 17-7ph stainless steel MIG wire.Three 10 pound spools cost me $750 + shipping.

[Craig Nadler]

I heat treated the helmet top to the TH1050 condition for 17-7ph stainless steel. I verified that the hardness was Rc43 as expected.

The helmet top was set on a 6"x6" post with a base during the testing to maximize the amount of force delivered. A small 0.1"/2.5mm deep ding is the most that Jaye Brooks was able to do to the helmet top with the two handed steel axe that he used during the last BotN event. IMHO, this test should surpass the worst case scenario in ACL bohurt as far as the impact force form a weapon blow.

[Baron Alcyoneus]

Hell, it might be RPG proof. TH1050 is pretty much the optimum for toughness. You can get harder, but there is a bit more risk of cracking.