I would like to ask if anyone could please help me with the following
I am using a standard hardened steel "pull out" dowel pin from
as a bearing shaft. I need to know the maximum load
the dowel / shaft can support without taking a permanent set and/or
becoming permanently deformed or bent. I need the shaft to always
spring back to its original position after the load is removed.
I emailed Mcmaster, but they were not able to give the maximum Yield
strength of the dowels.
Does hardening increase the maximum Yield stress? If so, is there a way
to calculate or estimate how hardening affects the yield stress ? If I
know the yield stress, then I can compare the maximum yield to the
bending stress given by my beam design program, and I think this will
tell me if the dowel can support the load without taking a set.
Here is what Mcmaster said about the dowels and material...
"Hardened Steel- Made from hardened steel such as C1541, or 4037 and
4140 alloy steel. Core Rockwell hardness is C47-C58 (surface hardness
is RC 60). Shear strength is the amount of force that the side of a pin
can withstand before breaking. Single shear strength is the amount of
force applied against a fastener in one place causing the fastener to
break into two pieces. Single shear strength is 130,000 psi. An
internally threaded tapped hole in one end of these pins lets you pull
them out with a removal screw or a threaded puller such as 92330A (see
page 3083 ) and reuse them. All meet ASME B18.8.2. Length tolerance is
I would appreciate any advice or suggestions on how I can get a close
estimate on this, and what would be a reasonable safety factor to
apply. Nobody could get hurt if the device fails, but I just need it to
be reliable. I have to consider several factors when choosing a shaft
size, and everything fits in a tight space.
There are tradeoffs and space constraints when going to a bigger shaft,
so I need to know how to estimate this in order to make the best
compromise. It's desirable to use the smallest shaft diameter possible,
that will support the load with a reasonable safety factor & not take a
Thanks for your help.
16 years ago