Why Through Hardening Matters

[BLR]

I would not want to make a slide out of Inconel. The Nickel content makes it gummy and not a very good material from a tribological perspective, at least in every grade I have seen in use. However, it has great oxidation resistance and strength at temperatures that turn Carbon Steel into Play-Dough. I guess you could coat it with some voodoo special coating from Bill to improve its properties.......

Perhaps Bill will correct me.... I have never tried to make something work with it below a thousand degrees F or so.

The copper helps with the gumminess.

This was a true metallurgical defect. It is, 1mm from the area, not registering on the C scale. I had to use the b scale. 2mm from the site, its right as rain. The problem was likely entrapped air in the casting that the bar stock was made from.

Disclaimer: I'm just a wealthy tinkerer, and I dont know how to make assumptions when it comes to kinematics and materials.



Then again, beer and pretzels!

[KevinB]

I would not want to make a slide out of Inconel. The Nickel content makes it gummy and not a very good material from a tribological perspective, at least in every grade I have seen in use. However, it has great oxidation resistance and strength at temperatures that turn Carbon Steel into Play-Dough. I guess you could coat it with some voodoo special coating from Bill to improve its properties.......

Perhaps Bill will correct me.... I have never tried to make something work with it below a thousand degrees F or so.

It oxides in a great black matte when heated to around 375 for an hour.
We work with a bunch of inconel for suppressors and muzzle devices -- I was more kidding about the Inconel - that stuff work hardens like a Mo-Fo leading to nasty scrap rates from broken tools

[Spr1]

Suppressors are a great application for Inconel (I would guess I600 or I625).

Tool related...... Years ago a new guy in our tool room was trying to make a test fixture part out of some grade of Inconel..... After creating a complete mess, his comment was "what is this s#%¥????"

[tomr]

This was a true metallurgical defect. It is, 1mm from the area, not registering on the C scale. I had to use the b scale. 2mm from the site, its right as rain. The problem was likely entrapped air in the casting that the bar stock was made from.

Sorry to go on. I get a casting void within the bar stock, but how did it make it into a finished slide? Was the void just inside the last milled surface and not seen till the sandblaster blew that away? Nothing funny looking before blasting? Was the wear/failure on the locking surface visible before the blasting?

[abu fitna]

Dumb question. Why mess with rebuild and not just swap slides? This is a nearly disposable item. There are a few modern sidearsm that might deserve retirement for ocassional viewing at end of useful life out of mere accumulated memories, but would not go out of the way to keep in service when replacement is easy. Nostalgia is for the gun safe, not the holster.

Unless I am missing something here.

[BLR]

So is there a reason he could not send it back to Glock (along with an eye test chart for their workers and inspectors)?

It is a customized gun. The customization played no role in this, nor Glocks choice of starting materials and use of finish, as much as I disagree with surface hardening over through hardening. The title of the thread is a bit misleading, in retrospect. You can't harden a massive inclusion. And the more I look at it, the more I think the little pocket is actually a void.

Let me be clear on this: this is a fluke. I'm not in any way shape or form criticizing the manufacturer.

In all likelihood, what happened is that when the foundry was cast the ingot that was used to make the bar that the slide was cut from, an air or slag pocket remained in that area. That happens.

The real lesson to learn here is this: Detail strip and inspect your guns periodically. This gun exhibited significant locking surface setback on the slide as a result of lack of effective bearing surface. I promise, this isn't the only gun out there like that. It's fun to have filthy dirty guns, and I'm guilty too. But this was a bit of nasty waiting to happen, and Glock is (liability wise) lucky it played out like it did.

[BLR]

Dumb question. Why mess with rebuild and not just swap slides? This is a nearly disposable item. There are a few modern sidearsm that might deserve retirement for ocassional viewing at end of useful life out of mere accumulated memories, but would not go out of the way to keep in service when replacement is easy. Nostalgia is for the gun safe, not the holster.

Unless I am missing something here.

Wasn't a stock gun. Was a very expensive custom one.

[Jaywalker]

Do I understand that the surface nirocarburization is the only hardening the slide gets?

[Alpha Sierra]

I've read many times that the Tennifer finish treatment is very hard but once compromised, their metal is not. Truth or fiction?

Tenifer, like all nitrocarburizing processes, is a surface hardening process. The metal under the case will be as hard as it was before it was nitrocarburized.

The hardness of the base metal is typically chosen based on the fatigue resistance properties desired out of the part in question and is achieved via a through hardening process if the material is not hard enough in its mill form.

The above is a gross oversimplification as heat treatment is a wide subject and can be done in many different ways.

[TR675]

Wasn't a stock gun. Was a very expensive custom one.

Silk purse/sow's ear.