Black Nitride finish is EXTEREMLY hard.

[AbitNutz]

Brother, I just tried to smooth down a Wilson #4 barrel link to fit in RIA C/P 22tcm barrel. It had been in with a batch of 1911 parts that was finished in Black Nitride by H&M Metal Finishing. I could not get even my killer Grobet file to cut it. I tested it on a non-treated #5 Wilson stainless barrel link and it cut on it like cheese. Unfortunately, that link was too long and the slide wouldn't lock up.

After quite a round with the link and my best aluminum oxide sandpaper on a ceramic tile, I managed to polish it enough to get it to go in the barrel channel. This finish it HARD.

I love the Black Nitride finish, especially over stainless steel. Not too fond of shiny guns. But man, that is the last time I try to fit a part after it has been treated.

[bangerjim]

There are several ways to do nitride coatings. One of the most popular in general industry is dissociated ammonia. Under heat/pressure, NH3 gas breaks down into it's components and forms a beautiful matte black finish on clean steel & alloys. The chemical change that occurs on the surface is tough and very resistant to wear and rust/corrosion. I used to sell D-A analyzers to the aerospace industry locally for just that chemical analysis reading to allow them to provide repeatable coatings to critical jet engine parts.

[AbitNutz]

I'm hard pressed to think of a downside to this type of finish. It's a finish, right? Not a coating? Finish and coating may be a difference only in my mind.

Anyway, for $200 bucks and 1 day turn around time, this is a no brainer.

[lefty o]

nitride is not a finish, its a heat treatment. same as melonite, tenifer, etc.

[bangerjim]

It is a "finish" created by/resulting from a specialized heat treating process in a controlled % nitrogen-rich atmosphere.

So yes......and yes.

[DougGuy]

Try to crown or ream the throat in a barrel that has been through any of those salt bath type treatments, they are a SONOFABOOGERBEAR buddy let me tell you! This is not just a surface finish either. If the barrel stays long enough in the hot bath, the hardening goes all the way through the steel, this is how Glock makes their barrels.

I had to design, draw up, and custom order TiALN coated carbide reamers made to my specs at several hundred dollars APIECE to throat these hardened barrels.

I did a glock 19 barrel for a guy and the CARBIDE cutter I use to cut crowns, shined it up! SHINED??? That's ALL???? Yup, barrel laughed at it and had to crown it in the lathe.

When reaming the barrel throats the reamer's flutes don't cut a curl or draw a chip like a machine tool does, it cuts and the scarf comes off as a dust not much different looking than cutting cast iron.

This is a whole 'nother ball park that these barrels are in, I have had to raise my rates on all the barrel work and add a surcharge to the cost of hardened barrels JUST to try and recoup the cost of the tooling and it will be a LONG TIME before these reamers are even paid for.

On the good side, I am still able to offer my services on hardened barrels at an affordable point. It's either this or go buy an aftermarket barrel that can be made cast friendly because so few are, but the LW and the KKM are a breeze to throat with conventional HSS tooling and they shoot lights out afterwards..

[AbitNutz]

H&M Metal Processing in Akron does almost all the treatment for the OEM's. When I drop off my various projects, there are just rows and rows of parts, barrels, slides, receivers, you name it...ready to be run through. Many of the folks that claim to do this themselves really just send it to these guys. H&M does no gunsmithing. You have to take it apart and reassemble it. There's no fitting afterward as no dimensions have changed...but if you have to alter the part afterward...good luck.

I love this finish. If you run a stainless steel part through it, it comes out a beautiful black and is about as indestructible as a piece of metal can be. I believe they can treat almost any kind of ferrous metal. Aluminum and the like, are not candidates. I expect they would just melt.

[John Taylor]

Just talked to another smith that tried to thread a barrel for a brake, said HSS did not even touch it.

[bangerjim]

H&M Metal Processing in Akron does almost all the treatment for the OEM's. When I drop off my various projects, there are just rows and rows of parts, barrels, slides, receivers, you name it...ready to be run through. Many of the folks that claim to do this themselves really just send it to these guys. H&M does no gunsmithing. You have to take it apart and reassemble it. There's no fitting afterward as no dimensions have changed...but if you have to alter the part afterward...good luck.

I love this finish. If you run a stainless steel part through it, it comes out a beautiful black and is about as indestructible as a piece of metal can be. I believe they can treat almost any kind of ferrous metal. Aluminum and the like, are not candidates. I expect they would just melt.

Al - - totally different molecular structures. You use hard anodizing with Al alloys. It give a very hard surface. Same principal - different molecules.

[bangerjim]

Just talked to another smith that tried to thread a barrel for a brake, said HSS did not even touch it.

That is why I use carbide tooling for everything. HSS just will not cut it (pun intended!) Even have most standard <1/2" NF/NC (running) taps in carbide. Amazing what you can find at the scrap yards! And sales in heavy industrial areas.

banger

[AbitNutz]

I'm hard pressed to find a reason I wouldn't have a firearm finished in Black Nitride.