On Wed, 06 Mar 2013 21:03:37 -0500, wrote:


Well, in building airplanes we have found a LOT of so-called 4130 is
nothing close to spec, and also a lot of 6061T6 aluminum. It's all
stamped with the proper identification, but the 6061t6 will crack if
bent to even twice the allowable radius, and doesn't weld worth crap,
and the 4130 is WAY below spec for tensile and yield.

Don't want to fly with that - so we don't accept chinese material
without independent confirmation of quality - and then only if
American, Canadian, or European product is not available.

It's certainly reasonable to be suspicious of material used in a
safety critical application where low factors of safety are typical.

--
Ned Simmons