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« on: January 16, 2010, 08:13:06 PM »
I have cut Ti every day at work for the last 25 years. We use only carbide tooling because HS doesn't hold up long. In the long run you will spend less on tooling with carbide. If you cut a lot of Ti, stay with carbide tools. HS drills work fine with it. Most of the time I like to grind drills so the point isn't perfectly centered so the drill cuts oversize a little. This goes a long way in making your drills last longer. Sometimes a standard drill will get dull and you will swear it got squeezed down as it gets melted down in diameter. Hand grinding a new drill will give it just enough run out to cut down on this problem. Tapping Ti is best done with special taps made for it. Standard HS taps don't tap it worth a darn. I wouldn't plan on reaming it unless you use carbide reamers.
As far as catching on fire goes. Thick chips around .002 thousandths thick or better are really hard to catch on fire unless your cutter is really dull. Really thin chips that are like steel wool burn white hot and are easy to catch fire. Same goes for saw dust from cutting it on a band saw. One time we had someone welding overhead on a crane and some sparks got in a chip barrel full of Ti and aluminum dust from the band saws. It burned and smoked up the whole building so we got the day off due to the smoke. Lucky there isn't much to burn in our machine shop. Big parts will not burn. If you ever get a thick block of Ti to catch on fire you have bigger problems than that block burning. That will take a lot more heat than you will make just cutting it. Even getting thick parts say 1" in dia. red hot to braze it won't set it on fire.
Not sure how 303 Stainless Steel would hold up to whatever you would like to make. 303 cuts nice and is much easier to work with.