Sorry. I never got any paperwork or info with it when I purchased it. I was only going on what a S&W rep said on the phone when I called about a problem. He said the cylinder was Titanium and the frame was that in an alloy (and the barrel was stainless steel). So...
At any rate, great customer service. I was able to take care of the problem myself. I purchased another S&W and they've done things to fix it on their dime (no fault of the gun...totally ammo related) including shipping...and they sent me spare parts to boot.