TLA Hardness Testing

[AxeHandle]

Had a forum member ask me about hardness testing of TLA innards. Would one of you guys with more knowledge in the area please elaborate a bit on this subject.

[squawberryman]

It's quite simple. Send the gun to a certainteed inspector who lives in Sorrento Florida.

[cubrock]

Grover was inconsistent about heat treating the lockwork on TLAs. Some of them are fine. Some aren't heat treated at all. And, you find everything in between. Keith DeHart told me that he wasn't heat treating in an oven under properly controlled conditions, but was carburizing each part by hand using Kasenit. When Grover expanded his shop and hired employees, he didn't make sure they knew what they were heat treating properly or that they were doing it at all. It is not uncommon to have a TLA with internals that are not heat treated.

Bottom line is that if you have a gun with improperly heat treated internals, the lockwork will grind itself out of time or even out of working in short order. This is especially true if you have on part (say, a hammer) that is properly hardened with other parts (say, a trigger) that is no hardened. The hardened part wears the non-hardened part down very quickly.

If in doubt, send the TLA to Alan Harton. He has fixed a number of them at this point. The reason so few of these were caught before the company went under is that a large percentage of TLA owners never shot/never shoot their revolvers much, if at all.

[bradshaw]

Dec 9, 2019 7:24:59 GMT -5 AxeHandle said:

Had a forum member ask me about hardness testing of TLA innards. Would one of you guys with more knowledge in the area please elaborate a bit on this subject.

*****


Stan..... a valid subject, too be sure. The subject of metallury & heat treatment receives all sorts of declarative misstatement in discussion. Manufacturers are aware of the syndrome and, abetted by the technical complexity of the subject, tend to avoid discussion. Nevertheless, the subject comes up.

Technical discussion aside, the subject is relevant to those who put firearms to hard use. The world of rifles, shotguns, auto pistols and revolvers is spattered with examples of poor, good, and excellent hardware encountered by those who burn enough powder. It takes shooting to learn strengths & weaknesses of a design and the hardware from which it’s made. Lee may be of some help here.
David Bradshaw

[bradshaw]

Dec 9, 2019 7:43:27 GMT -5 cubrock said:

Grover was inconsistent about heat treating the lockwork on TLAs. Some of them are fine. Some aren't heat treated at all. And, you find everything in between. Keith DeHart told me that he wasn't heat treating in an oven under properly controlled conditions, but was carburizing each part by hand using Kasenit. When Grover expanded his shop and hired employees, he didn't make sure they knew what they were heat treating properly or that they were doing it at all. It is not uncommon to have a TLA with internals that are not heat treated.

Bottom line is that if you have a gun with improperly heat treated internals, the lockwork will grind itself out of time or even out of working in short order. This is especially true if you have on part (say, a hammer) that is properly hardened with other parts (say, a trigger) that is no hardened. The hardened part wears the non-hardened part down very quickly.

If in doubt, send the TLA to Alan Harton. He has fixed a number of them at this point. The reason so few of these were caught before the company went under is that a large percentage of TLA owners never shot/never shoot their revolvers much, if at all.

*****

cubrock's take is clear & plausible. I've done or attempted to do trigger work on revolvers----not Texas Longhorn Arms----which lockwork lacked proper heat treatment, or any heat treatment at all. If soft steel was used on TLA hammer & triggers, the parts should benefit from case hardening. If the steel is like Ruger’s 4140, it it meant for through-hardening heat treatment, not case carburizing. Softer steels, such as Colt’s SAA, submit properly to case hardening. S&W hammers & triggers machined from drip forgings submit perfectly to case hardening; whether the parts would fare as well through-hardened, I don’t know. To stone engagement surfaces of the classic S&W hammer and/or trigger instantly defeat longevity.
David Bradshaw

[cubrock]

Dec 9, 2019 8:36:49 GMT -5 bradshaw said:

Dec 9, 2019 7:43:27 GMT -5 cubrock said:

Grover was inconsistent about heat treating the lockwork on TLAs. Some of them are fine. Some aren't heat treated at all. And, you find everything in between. Keith DeHart told me that he wasn't heat treating in an oven under properly controlled conditions, but was carburizing each part by hand using Kasenit. When Grover expanded his shop and hired employees, he didn't make sure they knew what they were heat treating properly or that they were doing it at all. It is not uncommon to have a TLA with internals that are not heat treated.

Bottom line is that if you have a gun with improperly heat treated internals, the lockwork will grind itself out of time or even out of working in short order. This is especially true if you have on part (say, a hammer) that is properly hardened with other parts (say, a trigger) that is no hardened. The hardened part wears the non-hardened part down very quickly.

If in doubt, send the TLA to Alan Harton. He has fixed a number of them at this point. The reason so few of these were caught before the company went under is that a large percentage of TLA owners never shot/never shoot their revolvers much, if at all.

*****

cubrock's take is clear & plausible. I've done or attempted to do trigger work on revolvers----not Texas Longhorn Arms----which lockwork lacked proper heat treatment, or any heat treatment at all. If soft steel was used on TLA hammer & triggers, the parts should benefit from case hardening. If the steel is like Ruger’s 4140, it it meant for through-hardening heat treatment, not case carburizing. Softer steels, such as Colt’s SAA, submit properly to case hardening. S&W hammers & triggers machined from drip forgings submit perfectly to case hardening; whether the parts would fare as well through-hardened, I don’t know. To stone engagement surfaces of the classic S&W hammer and/or trigger instantly defeat longevity.
David Bradshaw

His lockwork was made with soft steel. Alan Harton has done Rockwell testing on a lot of TLA internals and has provided me with a lot of his data. Some of the untreated parts were down in single digits on the RC scale.

[potatojudge]

Do you know if Alan through hardens the internals or if he surface hardens them?

[cubrock]

Dec 9, 2019 10:38:58 GMT -5 potatojudge said:

Do you know if Alan through hardens the internals or if he surface hardens them?

I think he surface hardens them, but you'd have to ask him to be sure.

[kings6]

I am not sure what process Alan does but every TLA I own has been sent to Alan for heat treatment and every one of the dozen or more have needed the internals hardened. I have my last one down there right now for that exact reason. Alan will send a record of the numbers for the parts when he returns the gun and the invoice.

[mike454]

It would be interesting to know what steel Grover was using for the internals.

[cubrock]

Dec 9, 2019 11:28:03 GMT -5 mike454 said:

It would be interesting to know what steel Grover was using for the internals.

I may have that in my notes somewhere. I can't remember, off the top of my head.

[mhblaw]

Thanks Robb, that is good news for the two I acquired from you. I am a shooter more than a collector so these get used.

[jared]

I know on my TLA the numbers were all over the place. The softest was the trigger. He was concerned with longevity of it so he welded the contact surface up with a tool steel rod and recut it.