< Any comparison to the very expensive "chromolloy" masts some talk
< about here?
Why yes, Dave, type 4140 steel that I mentioned is alloyed with both
chromium and Molybdenum (try saying *that* word 3 times fast! <grin>) and
is commonly referred to as 'chrome-moly' steel. It can be hardened to many
different levels.
I forgot to list some other common materials...ummmm lemmesee:
(Again from Machinery's Handbook, 23rd ed.)
YIELD STRENGTH
Steel, stainless, 304 & 316, annealed, 35,000 psi (at its softest)
Steel, Stainless, 316, tempered and work hardened, up to 100,000
ULTIMATE STENGTH (these materials just break without yielding - brittle)
Bricks, common light red - 40 (tension), 1,000 (compression)
Portland Cement, 1 month old - 400 (tension), 2,000 (compression)
Portland Cement, 1 year old - 500 (tension), 3,000 (compression)
Portland Concrete, 1 month old - 200 (tension), 1,000 (compression)
Portland Concrete, 1 year old - 400 (tension), 2,000 (compression)
Granite - 700 (tension), 19,000 (compression)
Note the difference in tension and compression for the rock-types.
This is why rebar is used in concrete, to add tensile strength for a
better composite building material. Fiberglass is another example of this.
The resin has compressive strength, the cloth has the tensile strength.
The tensile and compressive strengths of metals are much more evenly
matched, but can still vary.
- - ... MARK_N1LO...- -
>
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