On Sat, 22 Nov 2014 21:14:38 -0800 (PST), Sandarpan Mukherjee
wrote:
On Sunday, 23 November 2014 06:33:42 UTC+5:30, Ed Huntress wrote:
On Sat, 22 Nov 2014 18:25:32 -0600, Martin Eastburn
wrote:
On 11/22/2014 10:42 AM, Ed Huntress wrote:
On Sat, 22 Nov 2014 07:36:14 -0800 (PST), Sandarpan Mukherjee
wrote:
http://www.amazon.com/XMark-Commerci.../dp/B00JKM3BZU
The bar in the above link claims to have 240000 psi UTS and made out of a chrome-moly steel? Is it possible for such a high strength steel to be non-brittle enough for the application?
"Chrome-moly" usually means AISI 4340 steel or equivalent. 240 kpsi is
about the maximum, and elongation falls off sharply above 200 kpsi. At
225, it's down around 5/%.
Is that enough for your bar? I don't know. Maybe the real-world
application is no problem. At 5%, as a general matter in structural
applications, you begin to expect sudden failures. But maybe it's OK
for such a bar.
Be sure to watch the movie clip in the picture choices. Nice drop
tests that passed.
Martin
The video is interesting, but I was more impressed with the bending
test done in a machine. It's hard to tell what the actual load is on
the bar in those drop tests.
--
Ed Huntress
The actual load in the drop tests is easy to tell. Each plate is 45 lbs.
But that doesn't tell you what the load is on the bar, as a result of
being dropped with the weights on it.
For example, dropping it straight down and with the bar horizontal
imposes very little load on the bar.
Dropping it on a 45-degree angle to horizontal imposes a higher, but
unknown load. Note that the bar doesn't bend much in that test. The
load is not really very high, although it is more of an impact load.
--
Ed Huntress