will parkerizing effect threads on suppressor?

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will parkerizing effect threads on suppressor?

Post by mr fixit » Fri Oct 12, 2018 7:17 pm

Have a can in the works, tube and end caps are 4130 and 4140. It will be a welded can, but i have the mounting hole threaded. It's going to be a direct mount, 1/2-28" threads.

Do I need to cover the threads somehow, or will it not really matter?

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Re: will parkerizing effect threads on suppressor?

Post by Hannibalbarca » Fri Oct 12, 2018 7:26 pm

mr fixit wrote:Have a can in the works, tube and end caps are 4130 and 4140. It will be a welded can, but i have the mounting hole threaded. It's going to be a direct mount, 1/2-28" threads.

Do I need to cover the threads somehow, or will it not really matter?
I’d parkerize them to protect against corrosion but why use normal steel? Why not stainless?

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Fri Oct 12, 2018 11:46 pm

Like anodizing, there will be a tiny bit of material growth, but unless you're running interference thread fit already, it shouldn't be a problem. If you haven't cut threads yet, just go for class 2 (use GH2 or GH3 tap if not cutting single point).
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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Sat Oct 13, 2018 9:23 pm

Hannibalbarca wrote: I’d parkerize them to protect against corrosion but why use normal steel? Why not stainless?
I don't see that its needed. Stainless is heavier, and I think the corrosion issue is overblown.

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Re: will parkerizing effect threads on suppressor?

Post by yondering » Sun Oct 14, 2018 12:14 am

? Stainless is not heavier than carbon steel (not to the degree that you'd notice without careful measurements anyway, depending on alloy). Who told you that? Or do you just mean that you'd need to make parts thicker if you used something like 304 stainless?

Parkerizing won't have any effect on your threads, nothing to worry about.

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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Mon Oct 15, 2018 4:18 pm

yondering wrote:? Stainless is not heavier than carbon steel (not to the degree that you'd notice without careful measurements anyway, depending on alloy). Who told you that? Or do you just mean that you'd need to make parts thicker if you used something like 304 stainless?

Parkerizing won't have any effect on your threads, nothing to worry about.
Good to know on the parkerizing, thanks!
I read the info about stainless being heavier here, I think. I know it's not a big difference though. That, and I wanted a parked finish on the can.
Honestly, after fighting the 4140 on the lathe, I don't think I'll use it any more. No matter what I do/did I just can't get a nice finish. I've tried HSS bits and Carbide insert tooling, with rpms' from <75 to around 800. I've used Niagara tools slide rule to find speeds and feeds with little good. I honestly like 17-4 much better! All this is on a Logan 12" btw.

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Mon Oct 15, 2018 8:14 pm

mr fixit wrote:
yondering wrote:? Stainless is not heavier than carbon steel (not to the degree that you'd notice without careful measurements anyway, depending on alloy). Who told you that? Or do you just mean that you'd need to make parts thicker if you used something like 304 stainless?

Parkerizing won't have any effect on your threads, nothing to worry about.
Good to know on the parkerizing, thanks!
I read the info about stainless being heavier here, I think. I know it's not a big difference though. That, and I wanted a parked finish on the can.
Honestly, after fighting the 4140 on the lathe, I don't think I'll use it any more. No matter what I do/did I just can't get a nice finish. I've tried HSS bits and Carbide insert tooling, with rpms' from <75 to around 800. I've used Niagara tools slide rule to find speeds and feeds with little good. I honestly like 17-4 much better! All this is on a Logan 12" btw.
Stainless is 4 pounds heavier per cubic foot; 490 vs. 494

Annealed chromoly machines like crap. Get pre-hardened or bring your pieces up to a 35-40 Rc first. I do rough machining in the annealed state, harden & temper, then bring to final dimensions with a clean finish.
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Re: will parkerizing effect threads on suppressor?

Post by yondering » Mon Oct 15, 2018 8:46 pm

ECCO Machine wrote:
Stainless is 4 pounds heavier per cubic foot; 490 vs. 494
That's the kind of generic statement that spreads false information.

4140 weighs .284 lb/in^3

304 is slightly heavier than 4140 at .289 lb/in^3
440C is slightly lighter than 4140 at .282 lb/in^3
17-4 is even lighter at .280 lb/in^3

All three of those are stainless. It is false to just say "stainless is heavier". Some alloys are heavier than others, and that's true of carbon steel as well.

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Mon Oct 15, 2018 10:33 pm

yondering wrote:
ECCO Machine wrote:
Stainless is 4 pounds heavier per cubic foot; 490 vs. 494
That's the kind of generic statement that spreads false information.

4140 weighs .284 lb/in^3

304 is slightly heavier than 4140 at .289 lb/in^3
440C is slightly lighter than 4140 at .282 lb/in^3
17-4 is even lighter at .280 lb/in^3

All three of those are stainless. It is false to just say "stainless is heavier". Some alloys are heavier than others, and that's true of carbon steel as well.
Averages do tend to be generic in nature, and OP didn't cite a stainless alloy that was a contender to be specific. Carbon steel weights are generally calculated at .284 lbs/cu in. Stainless is calculated .286, which splits the difference between averages for austenic and martensitic alloys.
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Re: will parkerizing effect threads on suppressor?

Post by yondering » Tue Oct 16, 2018 2:43 am

Your averages are meaningless when the numbers can be completely reversed depending on alloy. The intelligent conclusion is that the weights are so close as to be nearly the same, not that "stainless is heavier". That's where people like the OP end up with bad information, because people like you spread it out there.

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Tue Oct 16, 2018 1:11 pm

yondering wrote:Your averages are meaningless when the numbers can be completely reversed depending on alloy. The intelligent conclusion is that the weights are so close as to be nearly the same, not that "stainless is heavier". That's where people like the OP end up with bad information, because people like you spread it out there.
They're not "my" averages. Industry standard for weight estimation calculations.

If it's such a pet peeves of yours, post a chart of all the stainless, carbon, chromoly, nickel, etc alloys and their respective weight per unit. Much more useful than sardonic pedantry in a thread with no such content indication in the topic.
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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Tue Oct 16, 2018 4:05 pm

Thank you gentlemen for your input. Let me further explain that what I read, and I do believe it was here that I read it, lead me to understand that heat treated 4140 and 4130 would actually be much stronger than an easily acquired stainless tubing and round stock and would have the additional benefit of being lighter. The strength was my biggest take away.

My thoughts at the time of planning were:
1.Corrosion is not as big of an issue as most people seem to believe,
2. 17-4 and 316 stainless are more than adequate strength wise,
3.untreated 4130/4140 is about equivalent in strength to 17-4 and heat treating brings the strength up tremendously above that,
4.being able to parkerize the tube might make the finish a bit easier to maintain.
All the above may be in error, but those were what I had in mind when planning

looking back.....untreated 4130/4140 sucks to machine at least for me so far, and what 17-4 I have worked with cut like a dream with a great finish. These 2 facts alone make me not want to use the 41xx steel again. However, I have it, and likely will use it since I have it on hand.

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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Tue Oct 16, 2018 4:08 pm

By the way, I'm going to bite the bullet and show some pics of this build soon. I'm not proud of the machine work, due to finish. The accuracy of parts I'm ok with if that makes sense.

The parts look like crap, but are to spec.

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Tue Oct 16, 2018 9:44 pm

mr fixit wrote:
My thoughts at the time of planning were:
1.Corrosion is not as big of an issue as most people seem to believe,
It can be. Introduce moisture (condensation) and untreated carbon steels or unanodized aluminum can suffer massive corrosion very quickly. I've seen significant pitting of unanodized 7075 baffles in my prototypes just a few days after running wet without cleaning afterward.
mr fixit wrote: 2. 17-4 and 316 stainless are more than adequate strength wise,
17-4 and 316 are in completely different leagues. 316 is austenitic (not heat treatable) with a tensile yield strength of 42 KSI. 17-4 has a TYS of 145 KSI annealed and 200 KSI in H900 condition
mr fixit wrote: 3.untreated 4130/4140 is about equivalent in strength to 17-4 and heat treating brings the strength up tremendously above that,
Annealed 4140 has a TYS of only 60 KSI, tempered will range from 130-200 KSI. Carbon, nickel & chromoly steels derive most of their strength from the heat treat, are often no stronger than A36 in annealed condition.
mr fixit wrote: 4.being able to parkerize the tube might make the finish a bit easier to maintain.
Maybe, depends what finish you were considering for stainless. I generally Cerakote, so it matters not whether the tube is carbon steel, SS, Ti, Al.
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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Wed Oct 17, 2018 10:58 am

I truly appreciate your input and help, please don't take what I'm about to say as adversarial. Just my thoughts. When I first read your post, I got some 'builders remorse', then I read a bit closer and thought about it.
ECCO Machine wrote:
mr fixit wrote:
My thoughts at the time of planning were:
1.Corrosion is not as big of an issue as most people seem to believe,
It can be. Introduce moisture (condensation) and untreated carbon steels or unanodized aluminum can suffer massive corrosion very quickly. I've seen significant pitting of unanodized 7075 baffles in my prototypes just a few days after running wet without cleaning afterward.
I never considered shooting it wet. Plus, any condensation will be burned off by shooting it a few times to warm it up
mr fixit wrote: 2. 17-4 and 316 stainless are more than adequate strength wise,
17-4 and 316 are in completely different leagues. 316 is austenitic (not heat treatable) with a tensile yield strength of 42 KSI. 17-4 has a TYS of 145 KSI annealed and 200 KSI in H900 condition
Completely different leagues, yes but that has no bearing on the truth. Obviously 316 is adequate, since manufacturers use it as well as several F1 builders on this site.
mr fixit wrote: 3.untreated 4130/4140 is about equivalent in strength to 17-4 and heat treating brings the strength up tremendously above that,
Annealed 4140 has a TYS of only 60 KSI, tempered will range from 130-200 KSI. Carbon, nickel & chromoly steels derive most of their strength from the heat treat, are often no stronger than A36 in annealed condition.
You made my point. From the comment above, 316 has a TYS of 42 KSI. As was stated, 4140 has a TYS of 60 KSI. Since 316 is adequate, annealed 4140 is stronger and therefore also more than adequate.
mr fixit wrote: 4.being able to parkerize the tube might make the finish a bit easier to maintain.
Maybe, depends what finish you were considering for stainless. I generally Cerakote, so it matters not whether the tube is carbon steel, SS, Ti, Al.
I was looking at a simple paint over park finish. If the paint cooks off, the park remains.

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Wed Oct 17, 2018 12:51 pm

mr fixit wrote:I never considered shooting it wet. Plus, any condensation will be burned off by shooting it a few times to warm it up,
The condensation happens when it's cooling off.

mr fixit wrote:Completely different leagues, yes but that has no bearing on the truth. Obviously 316 is adequate, since manufacturers use it as well as several F1 builders on this site.,
What truth? I never said 300 series alloys weren't strong enough (with enough wall thickness), you just alluded to 316 and 17-4 having similar mechanical properties. They don't.
mr fixit wrote:
You made my point. From the comment above, 316 has a TYS of 42 KSI. As was stated, 4140 has a TYS of 60 KSI. Since 316 is adequate, annealed 4140 is stronger and therefore also more than adequate.


Yes, of course it's adequate (again, with proper thickness). You were making a case for it being superior in mechanical properties to 17-4. They're similar in a heat treated state, but 17-4 is 2.5 times stronger in the annealed state.

All that said, the reason for using stronger materials is that you can go much thinner, ergo save weight. .035" wall 17-4 H900 is able to contain more pressure than .120" wall 316.
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Re: will parkerizing effect threads on suppressor?

Post by fishman » Wed Oct 17, 2018 1:25 pm

All this complicated commotion even before bringing titanium alloys into the mix. Dont worry, I'll save the day:

OP, you should use titanium. It's more better.
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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Wed Oct 17, 2018 4:34 pm

ECCO Machine wrote:
mr fixit wrote:I never considered shooting it wet. Plus, any condensation will be burned off by shooting it a few times to warm it up,
The condensation happens when it's cooling off.

mr fixit wrote:Completely different leagues, yes but that has no bearing on the truth. Obviously 316 is adequate, since manufacturers use it as well as several F1 builders on this site.,
What truth? I never said 300 series alloys weren't strong enough (with enough wall thickness), you just alluded to 316 and 17-4 having similar mechanical properties. They don't.
mr fixit wrote:
You made my point. From the comment above, 316 has a TYS of 42 KSI. As was stated, 4140 has a TYS of 60 KSI. Since 316 is adequate, annealed 4140 is stronger and therefore also more than adequate.


Yes, of course it's adequate (again, with proper thickness). You were making a case for it being superior in mechanical properties to 17-4. They're similar in a heat treated state, but 17-4 is 2.5 times stronger in the annealed state.

All that said, the reason for using stronger materials is that you can go much thinner, ergo save weight. .035" wall 17-4 H900 is able to contain more pressure than .120" wall 316.



I did not mean to infer you were not being truthful, I hope it didn't come across that way.

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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Wed Oct 17, 2018 4:35 pm

fishman wrote:All this complicated commotion even before bringing titanium alloys into the mix. Dont worry, I'll save the day:

OP, you should use titanium. It's more better.
If I could weld titanium, that would be my first choice.

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Re: will parkerizing effect threads on suppressor?

Post by fishman » Wed Oct 17, 2018 7:44 pm

mr fixit wrote:
fishman wrote:All this complicated commotion even before bringing titanium alloys into the mix. Dont worry, I'll save the day:

OP, you should use titanium. It's more better.
If I could weld titanium, that would be my first choice.
Why can't you? Get some argon and go to town!
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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Thu Oct 18, 2018 9:31 am

fishman wrote: Why can't you? Get some argon and go to town!
I need to practice I guess. I have a rebadged Lincoln Econo Tig machine at home. Many years ago, I worked full time as a welder in a SS sheet metal shop making SS tables and kitchen fixtures. I've done SS and mild steel but I have never even tried to weld aluminum or Titanium.

Guess I need to make a purge chamber and practice.

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Thu Oct 18, 2018 9:53 am

mr fixit wrote:
fishman wrote: Why can't you? Get some argon and go to town!
I need to practice I guess. I have a rebadged Lincoln Econo Tig machine at home. Many years ago, I worked full time as a welder in a SS sheet metal shop making SS tables and kitchen fixtures. I've done SS and mild steel but I have never even tried to weld aluminum or Titanium.

Guess I need to make a purge chamber and practice.
You can also flood the HAZ, but that technique consumes a lot more inert gas, would generally be used for larger parts that don't fit in your chamber.

Also, Ti will weld fine without inert atmosphere, but the HAZ becomes oxidized, losing some strength. Not terribly different from the loss of temper in the HAZ with steel or aluminum alloys.

I use Ti tubes pretty much exclusively, and sometimes Ti mounts/caps, but typically make threaded mechanical connections.
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Re: will parkerizing effect threads on suppressor?

Post by mr fixit » Thu Oct 18, 2018 1:28 pm

ECCO Machine wrote:........
I use Ti tubes pretty much exclusively, and sometimes Ti mounts/caps, but typically make threaded mechanical connections.
What thread pitch and thickness tubes should I be going for if I thread the Ti?

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Re: will parkerizing effect threads on suppressor?

Post by ECCO Machine » Thu Oct 18, 2018 4:20 pm

mr fixit wrote:
ECCO Machine wrote:........
I use Ti tubes pretty much exclusively, and sometimes Ti mounts/caps, but typically make threaded mechanical connections.
What thread pitch and thickness tubes should I be going for if I thread the Ti?
Depends on what you're going for. My ultralight critters, the Phantoms, are .035" wall with 36 pitch threads. The medium duty Furtivus are .045" wall with 30 pitch. My heavy duty Valkyrie are .070" wall with 24 pitch threads.

I mentioned it in another thread, but I torture tested one of my Phoenix pistol cans with 300 rounds of full auto fire over an 8 minute period, and that included 60 rounds from the M16 and 25 rounds from the 13" .308 machine gun last. The Aluminum baffles were gone, but the .035" wall Ti tube with the same 36 pitch threads mated to a 17-4 stainless booster housing and front cap were perfectly in tact. I replaced the aluminum baffles and continue to use it.
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Re: will parkerizing effect threads on suppressor?

Post by fishman » Fri Oct 19, 2018 11:39 am

mr fixit wrote:
ECCO Machine wrote:........
I use Ti tubes pretty much exclusively, and sometimes Ti mounts/caps, but typically make threaded mechanical connections.
What thread pitch and thickness tubes should I be going for if I thread the Ti?
.065" 24-28tpi is what Ive done. If I wanted to shed weight, id turn down the center of the tube and leave the ends alone. Its already really light, there isn't much weight to save
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http://www.silencertalk.com/forum/viewtopic.php?f=10&t=141800&p=955647#p955647

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