Vent linners

[Ga.Smokey]

Has anybody ever nitrided a vent linner?
I have access to amonia nitriding.
Supper hard and durable.approaches 90 rc used in the power plant industry for harsh abrasive conditions to combat wear in high preasure situations
Can be applied to carbon steel

 

[MrTom]

I think most vent liners are hardened steel to begin with.

 

[ElDiablo]

Or tungsten carbide

 

[Ga.Smokey]

Or tungsten carbide

Tungsten would be nice.
The nitride is even harder
Wipes out carbide cuters in a single pass.

 

[Ga.Smokey]

I think most vent liners are hardened steel to begin with.

The ones I saw were 35 rc

 

[jsteurrys]

Or tungsten carbide

Just go with the bushing as they have proven to be superior to vent liners. I switched over to bushings when the first came out except for a couple of Knight MK-85s which use vent liners. Those get used very little.

 

[michiganmuzzy]

If you can get a ventliner done cheap then definitely try it out. I have a bunch of VL and would love it if they were a lot harder.

 

[Ga.Smokey]

If you can get a ventliner done cheap then definitely try it out. I have a bunch of VL and would love it if they were a lot harder.

If I got them done at work I'd just throw them in a run of nitralloy
It's a huge system 100 pieces wouldn't take up any room.

 

[Bowanna]

If I got them done at work I'd just throw them in a run of nitralloy
It's a huge system 100 pieces wouldn't take up any room.

Pm me an address and I'll send you 3 or 4 to throw in, hell, somebody gotta go first.

 

[ljc]

How much is it going to reduce the hole?

 

[michiganmuzzy]

Nitriding should not reduce the hole any measurable amount. It just changes the surface of the metal.

 

[michiganmuzzy]

If I got them done at work I'd just throw them in a run of nitralloy
It's a huge system 100 pieces wouldn't take up any room.

I’ll send you a few and you can keep one for your trouble. PM me your address.

 

[Ga.Smokey]

How much is it going to reduce the hole?

That's the big question.
So my thought is to drill some in steps 31/32 33/34/35/36
And see which one comes out at 31 32
With some parts we see a growth of up to .0015 .0023
On all surfaces.
The process is not like salt batch nitride that we see on guns.
It's much harder.....
Not black in color
Like I said before once it's done you can't touch it with carbide cutting tools.
We have to Burry a tool and try and get underneath it.
Usually takes .04 diameter to cut it out of the way.

Somewhat of a pucker factor when you only have .06 of stock to hit a .0005+/- tollerance.
I've seen shafts nitrided that were in service 10/15 years at exstream heat and pressures that have lost but a few 10ths on there wear surfaces.
That being suspect as the conditions of metrology are not identical.
The second question is thread clearance in the breach plug.
There should be enough but it's going to be interesting to measure over wires or pitch mic before and after process.

 

[Ga.Smokey]

Nitriding should not reduce the hole any measurable amount. It just changes the surface of the metal.

That in theory should be correct.
And in my experience is with salt bath nitride we see in gun use it generally is accepted.
This process is much different in that it uses a furnace and ammonia and nitrogen gasses.
My view is that the heat expands the metal and the process locks that dimension at the chemical quench.
So it's material dependent.
Salt bath is not near as hard as this process.

 

[michiganmuzzy]

Im thinking that something as small as a vent liner won’t expand much with the heating. .001” or .002” change(larger or smaller) in the hole size at most, which shouldn’t be noticeable to 98% of users.

 

[Ga.Smokey]

Im thinking that something as small as a vent liner won’t expand much with the heating. .001” or .002” change(larger or smaller) in the hole size at most, which shouldn’t be noticeable to 98% of users.

I'd agree
It is there though and being a precision machinist it's hard for me not to hit the number lol....
What I don't know is what the performance would be if it closed up to say .028 from .031 ??

 

[Ga.Smokey]

I'd agree
It is there though and being a precision machinist it's hard for me not to hit the number lol....
What I don't know is what the performance would be if it closed up to say .028 from .031 ??

I've got the tooling on the way to make some from grade 8 screws.
There pretty tough as is 36rc

 

[DannoBoone]

That ".028" measurement is vaguely familiar. Seems as though someone on Doug's years ago, prior to 2010 was using liners with that size hole. But I don't recall how well they worked.

 

[Ga.Smokey]

That ".028" measurement is vaguely familiar. Seems as though someone on Doug's years ago, prior to 2010 was using liners with that size hole. But I don't recall how well they worked.

Kinda why I'd like to stay in the .031to .035 range know results.

 

[ElDiablo]

What I don't know is what the performance would be if it closed up to say .028 from .031 ??

I doubt you’d see any difference in .028 vs .030

I’m using .030, .035 and .040 bushings and can’t discern any difference in reasonable temps. Maybe a little more back pressure with the .040”. And…small grain powders like N120 will fall right through a .040 bushing.