On Wed, 19 Oct 2011 08:08:52 -0700, "Steve B"
wrote:


"larry moe 'n curly" wrote in message
...

Jim wrote:

While turning slightly I suddenly found myself on the floor. The
top bracket, a box shaped assembly to mate the chair to the gas
strut portion had sheared.

The exact same thing happened to my chair, only I caught it before it
collapsed. There was a 1-2" crack from one edge to a 1/2" hole. How
can thick steel like that crack on a chair when wood holds up fine?

A combination of things: Poor welding, poor design, poor load distribution,
poor triangulation and bracing, and the poor chair that has to hold up some
fat ass who thinks it's a recliner.

BTW, most of the metal is .065" thick.

Steve

Wood does not fatigue when it bends. Metal does. Steel can flex more
than aluminum before it cracks - unless it is hard (work hardened) to
start with. Cold stamped steel is work hardened and rather brittle
-particularly no-spec recycled chinese scrap.