Take a look at the dropouts a threaded axle will chew up aluminum but not titanium. One maker refuses to use horizontal drop outs on titanium because it is too slick to hold the axle. 6Al 4V titanium used for some dropouts is brittle it chips like flint when you cut it the chips will be around 1mm.

Aluminum welding lays down a larger bead.. tig steel will respond to a magnet,

So if the weld bead is small and its not magnetic .. could be Ti.


dig out the pen knife, and take a chip out. they will cut with a different effort.

http://bikeforums.net/attachment.php...hmentid=231148

Titanium




http://bikeforums.net/attachment.php...hmentid=231147

Not Titanium