Titanium 'Internals'. Why Not? (Sc/Ti models)

C

Commander Fan

New member
One of my co-workers was along while I ordered a new S&W 340PD on Tuesday. While giving him a little description of the design--trying to describe what makes them so light(and costly)--I brought up the fact it uses stainless-steel internal componants. He asked, "If they're trying to make it so light, why not use titanium in place of the steel parts also".

Thinking I knew what I was talking about, I stated that titanium is usually considered more 'brittle' than steel, and that given the same mass, is not as stong as steel.

Being an all-out NHRA drag racer, he quicky said, "BS...half my moter is built with titanium parts, including valves and valve-springs. Many of the 'high-dollar' competitors are running Ti axle-shafts and other drive componants. It is by NO means brittle, and is VERY strong."

Well, I was stumped. I had heard all the bad reports of Ti 1911 ejectors and extractors breaking due to their 'brittleness'.

So why doesn't S&W use titanium throughout? I'm just wondering what the metalurgists(self-practicing:) or other) here think.

BTW-This is my second AirLight model, with the first being the 342PD(.38+P). Of course, I traded it to finance my Kimber Pro Eclipse, and have missed it ever since. I got the chance to fire the 340PD version(scandium alloyed .357) on DPMS's newly aquired range last weekend and loved it. I put 3 cylinders of the .357 158gr Blazer through it before the owner made me give it back. Mine is expected to arrive on Wednesday. I've already replenished my .38/.357 supply, and dug out my old J-frame speedloaders and holster. Can't wait!

Oh ya, it was $579 for the 340PD, but I paid $40 more for the 342PD when it first came out.

Advanced thanks for any information on the usage of metals.
 
I believe Titanium alloys are too "soft" (too low Young's Modulus) to use on high-stress, wear critical areas like hammer and trigger (especially where they interface). The interface wouldn't hold the required edge for very long. In fact, I doubt that they are stainless, either, since good old high-carbon steel is usually used on the firing mechanisms, where wear would be trouble. They might be chrome-plated steel.

The beauty of titanium is that it's strength/density ratio is much higher than steel, so by replacing it on the frame and cylinder, the weight is greatly reduced for the same strength. In your buddy's hotrod, all the places where titanium touches other parts, you'll find a bearing or bushing seperating them, as Ti would wear too fast. Strong, but soft.
 
I know in certain situations "Ti" can flex too much. "Sc" has a more controllable amount of flex....its more "tunable" if you will.

Some "high wear" parts in guns are referred to as " Ordinance Steel" this is just another name for 4140 HT or "Chrome Moly", is used in alot of high strength-wear/low weight applications.

Stainless can be used in virtually the same applications, as there are literally 100's of stainless steels. You can case harden most Stainless Steels and make the surface wear as long as any other Alloy/Steel.

Hastelloy is an Stainless based alloy that has incredible strength/weight properties while retaining great resistance to chemical attack/breakdown. Just one example......

Shoot well
 
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C.Fan I also started with the titanium .38special +p from S&W, mine was a model-337, gave it to my brother last Christmas. I now own the model-386PD and model-360. I personaly am glad that S&W used some steel becouse at 12 oz. my model-360 is as light as I would want a .357MAGNUM to be! I love the light weight becouse I can were it on my leg all day and not even feel it, I could not do that with my SP-101. So light these guns have many applications.
In my view I think S&W did a great job designing these revolvers. A little pricey but worth every penny! ;)
I also want to complement you on your choice of the model-340PD, when I bought my model-360 the model-340 was not out yet, now I wish I would have waited.
 
Titanium is just plain soft compared to good, hardened steel.

This same issue comes up every so often with good knives. You can't make a good knife blade out of titanium because it won't hold a good edge for a reasonable amount of time. When Benchmade used to make a Ti-bladed knife, they had to put a hard coating on the edge--and that was actually what was sharpened.
 
I would love to have one of these new J frames but until S&W renigs on their agreement with the Klinton administration, I'll just have to keep using my fine old Model 60.

7th
 
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