I want to have a barreled action finished with the black nitride (ferritic nitrocarburizing) treatment, which from what I read involves heating the steel to around 1000 degrees. The barrel has a front sight ramp that was silver soldered/brazed on and I'm wondering whether that will affect the process/finish? I have an email about this into the company that offers the service and am still waiting to hear back. I recall that the Remington 700 bolts are brazed together and I suppose 700s get finished with black nitride at times.

Just wondering whether anyone here has already been down this road already and whether the brazed joint had to be removed and cleaned before treatment or was it unaffected by the process or did the sight ramp (or whatever part) come off the gun? Thanks in advance!

This reminds me that I sent a question via email to H&M more than a month ago. Still no reply.

I'm also interested to learn more about your inquiry.

Thanks, Dinny

I’ve sent hundreds of them out to be nitrided. The answer is, it depends. If the joint was properly fitted and brazed they’ll stay on with no issues, silver solder melts at 1250deg IIRC. If they are poorly fitted and brazed I’ve had them come off. A poorly brazed sight ramp may stay on under normal conditions for decades with one tiny point of contact actually brazed but the extreme heat and expansion of the nitride process may make it pop off. The only way to really tell is to do it.
If everything is good it shouldn’t. If not and they come off we just learned to deal with it. Sights that came off I’d usually drill and tap them back on with a screw hidden under the dovetail and a good epoxy under the ramp. Bolt handles I’d clean up and TIG weld before sending back in to be treated again. Not much else to do. I’d say normally your odds are %95 or better of no issues.

Dinny, It's not the first email to them that's gone unanswered (although I sent this one Saturday so I'm not expecting a reply until tomorrow at the earliest), but emails seem to be generally overlooked by a lot of companies. I keep trying to do it because of hearing problems using the phone. I can hear pretty good in print . I'll try to remember to post back when I get a response. I may also throw caution to the wind and call them today!

TheKid, thanks for the reassurance. I'm fine with reuniting the ramp and barrel with the screw and epoxy; do you know whether epoxy is stronger than Loctite Black Max? I have some of that as well.

Just heard back from them this morning and was told that if the solder joint on the ramp gives up while it's in the tank they can't recover a part that small, so I will remove it first. I think it was put on with Brownell's low-temperature silver solder anyway.

I sent two last week. Should be getting them back next week. I've heard nothing but good about their process. (QPQ)

Address or email on the nitride company thanks

blacknitride.com
H&M Metal Processing
1414 Kenmore Blvd.
Akron, OH 44314

They also have a facility in Arizona.

They also opened one in Florida recently.

Jacob Coons is the receiving manager at H & M and the one who kindly answered all my questions.

I got mine back today and they look nice. You can't tell the difference between the stainless barrel and chrome moly receiver.

If you're worried about the braze failing due to process temp, another option is to go with the DLC process. It is a gas plasma nitriding process that has similar mechanical properties and looks very similar to QPQ nitriding, but is done at much lower temperature. The other advantage of DLC is it can be applied to any metal, not just steel. The only downside is it's a "line of sight" process that cannot be applied inside the bore, so if part of the reason you wanted to go with QPQ was for additional wear-resistance inside the bore, DLC won't give you that.

Would soldering on after nitriding destroy the finish? To messy?

What is the approximate cost for getting the black nitride finish on a barreled action?

I've never done a gun, but the guys in this link said $150 for a barreled action

https://www.24hourcampfire.com/ubbt...rue/re-h-m-nitriding-review#Post15859797

We've done it for industrial parts in a high wash down (caustics and acids weekly, humid environment daily) that we couldn't source in stainless. It has always held up well.

I had H&M do a muzzleloader for me and it's great. My "covid project" M70 will be back from JES soon and will need new metal finish. I'm on the fence about either having H&M nitride it or Mahovsky's Metalife (hard chrome) it. Similar price for both but they can't nitride the aluminium trigger guard. Guess it boils down to if I want black or silver. Thought about Cerakoting but can't justify spending more money for a less durable finish.

Heating a bolt action receiver to 1000*F will ruin the heat treat and make an unsafe rifle. 1000*F is glowing red hot.

Wow, an armchair metalurgist here. There are thousands of guns so treated every year. 1000⁰ doesn't even come close to the tempering heat used. I've never had an issue other than sometimes reduced performance in the bore

1000 is showing color.
Glowing red would be close to, but under critical, 1300 maybe.
Approaching quench, 14-1500, depending on steel type

Tempering heats would be lower.
Under 1000 for spring.

400ish for a blade.

But, I won't begin to claim to be a metalurgist.
Only with the help of spell check do I dare try to spell it.

H&M quoted me $250 plus return shipping of about $35.

By the way, are there steel parts that shouldn't be nitrided? H&M says no springs, titanium or aluminum. I'm thinking here of scope ring screws, assembly & pivot pins and tiny setscrews. I want to get all of the visible (and most of the internal) parts treated so it's uniformly the same color and smooth up the action in the process. Seems like there's not much reason to harden scope ring screws with the treatment, but maybe I'm missing something.

Huh, in the Video H&M guys say that they do the corrosion protection bath after the nitride bath.

Just heard back from H&M about the small parts: "Do not nitride the firing pin unless you know the material and the hardness." But they said all the other small parts were fine (except springs). Here's hoping my action will be almost as smooth as a Krag when they get through with it

My guy in Phx does mine for $60

Care to share?

Phoenix Heat treat

I think you have to do off in person

I see they offer "gas nitriding". How is the finish compared to the salt bath QPQ process?

Most guys charge 60 bucks just to tear down and re-assemble a firearm these days... so I’m assuming you sent him parts.

Interesting that Nitriding is normally done after stress relieving, and then it does add a 1/2 a thousands according to this link .

https://www.metlabheattreat.com/nitriding.html

You don't know what you are talking about.

I see from the link above that they are really heating the part enough to ruin the heat treat. For reference, the correct temperature to draw a spring is about 750*F. A tumbler is drawn to about 450*F. Depending on the exact alloy a 4140 receiver would be drawn to a temperature somewhere in-between those figures. Heating a receiver to 1000*F and cooling it slowly would result in a dead soft state. When fired the locking lugs would set back making it impossible to open the bolt. I would not let them touch my rifle on a dare.

For items that are not heat treated, like pistol slides and frames I see no issue.

You should really stop talking out your a$$ while you can. We are not making springs. 1000⁰ F does not make steel " dead soft" I've been making knives and guns for many years. To make steel dead soft you have to heat it until it reaches critical temperature. This is the point at which it quits being magnetic. Depending on the steel 1800-1900⁰

I called and talked to Glen Harrison ( Defiance machine- Phoenix machine at the time) he told me it was ok to salt bsth his action to 1000⁰. His temper was about 1070⁰ f. The added hardness of the surface would make up for a lost point in temper draw back.

With 4340 or similar Chrome- molybdenum steels this is fine. I have nitrided dozens of actions. I disassemble them and only send the parts i want treated. No springs or pins. They come back tougher than he'll and corrosion resistant.

ALL Glock slides are nitrided. I suspect they know something about metallurgy.

I don't like what it does to the bore. I've had 2 barrels that shot poorly after nitriding. I won't do any more barrels.

Ok, springs I get. Are most pins already hard enough because they're made out of something like drill rod stock and heat treated to begin with?

I beg anyone who is thinking about heating an action to 1000*F during a nitride process to contact the manufacture of the rifle before they proceed.

Per the heat treating chart for 4140 steel heating to annealing to 1000*F severely weakens the yield and tensile strength. This is serious stuff, if an action fails you can die.

https://www.practicalmachinist.com/...-special-application-4140heat_strain.jpg


https://www.snipershide.com/shooting/threads/to-nitride-or-not-to-nitride.6252625/
Where the nitriding becomes relevant is that in this instance, as in: When you step on your crank and make a mistake like this, the action does not merely split apart and lock up the bolt. It goes BOOM and gun parts become shrapnel.

I'm sure glad that you don't want yours done. One more out of the waiting line. Yes, I started having this treatment done about 20yrs ago and ain't had a problem yet.

Literally millions of guns have had this treatment.

Yep, he's a liberal for sure- worried about everything

Noting like being insulated by a stranger who does not have a clue what he is talking about.

Fact, not a liberal........

Fact rifle actions are heat treated for specific properties such as strength and durability. The heat treatment temperature are specific to the alloy.

Fact, the nitride process is a newer form of case hardening. The the high heats involved changes the manufacturers' heat treatment of the bolt and action. It can create a much harder core that originally intended my the manufacturer. It depends on the steel used it make it in the first place. If you do have a failure, say due to a bad reload, a brittle action can grenade and kill you. A a brittle bolt can shed it's lugs and kill you.

Check with the original manufacturer before you do this. That is all I am saying. This is not some obscure theory I pulled out of my ass. It is basic knowledge that anyone worthy of the title "gunsmith" should know.

20210319

First chart shows tempering range and colors for temps.

Second shows effects of temp on hardness.
Notice temps in first for tempering.


Second is for drawing knives made of 1095 back from brittle hard
To the range of normal knives. Softened, but still hard.

No idea how nitriding affects a gun.
But there is some BS being thrown around here,

And Scota is not wrong in his talk of temps.

The wild card in this is the post treatment time and soak time.

In my younger years I worked for a metalurgist in spokane by the name of Bob Williams. Bob owned Pohl spring works and I did what I could to pry knowledge from his head.

While it is true that the 1k will potentially affect the draw, we don't know the potential carbon migration, chill slope....etc.

There's obviously some surface hardness increase but at what cost? If anyone is curious, treat a recoil lug and make varying depth of grind across one side. Smack it in the tester and see how much if any change in RC is had....and how deep.

I don't recall exactly what our time and temos were for drawing 4140, but 4 hours at 600 rings a bell. A rifle action is no where close to that hard.

I knew it would get a reaction

You are winning about a treatment that thousands use with no issues yet you persist to belittle us

Came across this thread on the Custom Rifles and Wildcats subforum:

https://www.24hourcampfire.com/ubbt...15874818/nitriding-question#Post15874818

The subject of getting the last of the salts out of the receiver/barrel interface comes up and there is discussion about whether to remove the barrel from the receiver. I specifically asked H&M about this and was told that I needn't remove the barrel from the receiver. I'm guessing they came up with a way to get all of the residue out of the barrel/receiver threads? Or maybe I need to call them about it?

Scotta45-70 NOTING??? INSULATED??????????????????????????????????????????????????????????????????

https://www.americanrifle.com/shop/product/mausingfield-bolt-action-2

About halfway down the page:

SAFETY AND TESTING

Read this section! You might actually find it interesting and entertaining.

...

An action needs to have a margin of safety to resist the dangerously high loads resulting from misuse. The margin of safety stems from both proper design and proper heat-treatment of the steel from which the action is made. Therefore, the Mausingfield action must never be subjected to temperatures above 400°F (204°C) for any reason, because doing so will significantly weaken it and compromise its safety margin. The Mausingfield must not be subjected to high-temperature surface treatments such as ferritic nitrocarburizing or salt-bath nitriding, because such treatments are conducted at temperatures ranging from 900-1200° F (480-650° C). These treatments are marketed under several trade names, including Nitrotec®, Tufftride®, Tenifer®, QPQ®, and Melonite®. While these finishes might be suitable for some firearms, they are not suitable for the Mausingfield and may not be suitable for other bolt actions either.

AND... the last paragraph on THE SAME PAGE that quote came from:


SURFACE TREATMENT

The Mausingfield is supplied with a salt bath nitride surface finish to harden and blacken its surfaces. The resulting finish effectively resists corrosion and reduces friction thus enhancing the smoothness of the action. The bolt head is coated with diamond-like carbon (DLC) surface finish. DLC is an extremely hard and wear-resistant layer on the exterior surfaces. This will reduce the friction between moving parts, thereby enhancing the smoothness of the action. DLC treated surfaces hold oil which enables them to resist corrosion reasonably well.

Check it out: https://www.americanrifle.com/shop/product/mausingfield-bolt-action-2

Whether or not salt bath nitride treatment is a good idea depends entirely on the specific alloy used, the geometry of the part, and the material heat treat condition prior to SBN.

Mausingfield changed their material used in the action and has since then offered salt-bath nitrided finish. The paragraph you quoted from above is old information from the first gen Mausingfield that they forgot to remove from the website. The current Mausingfield Gen 2 is suitable for salt bath nitriding and is offered with it directly from ARC.

Gas nitriding is a much lower temp process, and is usually a physical vapor deposition (PVD) process that has "line of sight" application, meaning that it won't deposit the coating on internal surfaces deep within narrow cavities or bores, as opposed to salt-bath nitriding that is submerged in a high temp cyanide salts bath, affecting all surfaces of the part exposed to the bath. Gas nitriding is also a deposited coating (albeit an extremely thin one) rather than a case hardening surface transformation like salt-bath nitriding, and it can thus be applied to a wider range of materials. Depending on the chemistry, gas nitriding can be black, and if so, it looks similar to salt-bath nitriding, but a wider range of colors and sheens are possible with gas nitriding.

Edited to add: DLC (diamond-like carbon) is an example of a type of gas nitriding/PVD. TiN (titanium nitride) is another.