The Home Machinist!

Ref: http://www.advanced-armament.com/pdf/ma ... 4-1000.pdf

Scroll down where it says Flash Hider Material

What is High Temp SS?

Ref: http://www.advanced-armament.com/produc ... 29#pid=119

Their description says it is a "high strength corrosion-resistant aerospace alloy"



I've also heard it is some type of prehardened SS.

Any idea what it is? What type of tooling to machine it on a lathe and mill?

Thanks X

Exodus wrote:What is High Temp SS?

Usually 321 or 347. But not guaranteed.

I'm familiar with iconel, like it says they use for the silencer material. We used in in the diesel exhaust water scrubbers for the float valve in underground coal mining machines we built, primarily because it is highly corrosion resistant.
It's also excellent for high temp applications, and is very expensive. Seems I remember a piece of 1/4"NC x 8" inconel all thread was about $120.00, and that was over 20 years ago. Biggest reason for that I think, was the stuff was not machining friendly. We built some prototype parts out of the stuff in house, and it work hardens real easy & real fast. I remember unkind words out of the machine shop.
If I remember right it was Inconel 625 we were using. Not sure what the difference is between that & the 718.

High Strength, High Temp and Aerospace alloy are just buzz words. The finish would have more to do with corrosion resistance than the base material and all cres is pretty heat resistant.

As I recall, 321 and 347 cres are weldable but not heat treatable but it has been a long time since I have specified materials.

I have got to scrape out some of those cob webs

Best regards, Jack

Cob webs??? Good....it's not just me.... I feel better now

http://www.specialmetals.com/products/index.php

Check these guys out. Mfg of all the Inconel stuff.

Hey Dieter....Isn't 321 a mix of 304 & a dab of titanium? Seems like I remember that..... or suffering from more cobbs.....and their evil little tangled webs....

warmstrong1955 wrote:Hey Dieter....Isn't 321 a mix of 304 & a dab of titanium? Seems like I remember that.

If you don't mind me jumping in here, you're pretty close to being correct. Analysis of the two materials indicates that the only difference, aside from the titanium you spoke of, is the percentage of nickel has a different allowable range. With 304, it's 8.00/10.00, and for 321 it's 9.00/12.00.

347 is the same, although they add columbium and tantalum instead of titanium. The purpose in both cases is to overcome the dangers of intergranular corrosion.

None of the 300 series stainless alloys are hardenable by a heat treating process.

Harold

Got some more info.

It is probably NOT INCONEL™ 718. A finished product, roughly 1" X 2 1/8" retails for $59 which pretty much rules out 718.

Some of their other literature suggests 17-4PH.

Thoughts?

Well..... you made me do a little searching on the net, as I'm not really familiar with 17-4PH.

http://www.specialtysteelsupply.com/17- ... -steel.php

Reading the propaganda on the M4-1000, it's talkin' about temps of 800, and looking at the specs..... 17-4PH is not recommended for temps over 572 F.

http://www.azom.com/details.asp?articleID=967

I think Dieter is right about 321 being a good choice..... My use of various types of SS has been in applications involving corrosion problems, not temperature applications. That's how I learned about Inconel. I think I'd do some searching on the net, and maybe a phone call or three....

Just a bit curious if the gun's barrel is stainless too? If it is then I could see the reasoning for the same/similar metal. If it isn't then why not use the same as the barrel? Going to take a long time to wear out the "attachment" under normal usage. When you do, you can make another if you didn't make spares at the time of the first and it would still be cheaper than using an exotic alloy

Pete

Inspector wrote:Just a bit curious if the gun's barrel is stainless too? If it is then I could see the reasoning for the same/similar metal. If it isn't then why not use the same as the barrel? Going to take a long time to wear out the "attachment" under normal usage. When you do, you can make another if you didn't make spares at the time of the first and it would still be cheaper than using an exotic alloy

Pete

The barrel is stainless and the flash hider will at times live inside a silencer, where heat can be rather high. The flash hider will also act as a QD adapter.

Here is a couple examples: