1/4" dog head set screw shear calculation
1/4" dog head set screw shear calculation
(OP)
I am supporting a failure analysis on a set of 4 dog head set screws that failed on a mechanical seal. I am trying to determine the minimum point at which shear failure could have occurred based on the materials, cross section etc. Here is the write up I have performed thus far, do these calculations appear correct? It seems to be a straightforward problem, I just want to make sure my solution is correct before forwarding on to the customer.
Rough shear strength estimation for setscrew, part 26 on drawing:
Ultimate Shear Strength = .57 x Ultimate Tensile Strength, engineering forums recommend using .50 x Ultimate Tensile Strength.
316 SS Ultimate Tensile Strength from www.onlinemetals.com: 89900 psi
Ultimate Shear Strength = 89900 x .50 = 44950 psi
Setscrew diameter: 1/4 (drawing dimensions: .250 - .210, .156 square tip)
Height of holding area: .089 (sleeve)
Cross section: .156 x .089 = 0.013884 in^2
Equation: (Failure Load)/(Area) = Ultimate Shear Strength
Failure Load = Ultimate Shear Strength x (Area)
Failure Load = 44950 psi x (.013884 in^2 x 4)
= 2496.3432 lbs of force
Thanks
Rough shear strength estimation for setscrew, part 26 on drawing:
Ultimate Shear Strength = .57 x Ultimate Tensile Strength, engineering forums recommend using .50 x Ultimate Tensile Strength.
316 SS Ultimate Tensile Strength from www.onlinemetals.com: 89900 psi
Ultimate Shear Strength = 89900 x .50 = 44950 psi
Setscrew diameter: 1/4 (drawing dimensions: .250 - .210, .156 square tip)
Height of holding area: .089 (sleeve)
Cross section: .156 x .089 = 0.013884 in^2
Equation: (Failure Load)/(Area) = Ultimate Shear Strength
Failure Load = Ultimate Shear Strength x (Area)
Failure Load = 44950 psi x (.013884 in^2 x 4)
= 2496.3432 lbs of force
Thanks





RE: 1/4" dog head set screw shear calculation
Shear area of the dog point is pi*d^2/4 = 0.0191 in^2.
Ted
RE: 1/4" dog head set screw shear calculation
Is it not a simple cross-sectional calculation, W x H (with width = diameter)? Maybe I'm looking at this all wrong.
RE: 1/4" dog head set screw shear calculation
Ted
RE: 1/4" dog head set screw shear calculation
RE: 1/4" dog head set screw shear calculation
Thanks for all the help.
RE: 1/4" dog head set screw shear calculation
RE: 1/4" dog head set screw shear calculation
RE: 1/4" dog head set screw shear calculation
Rotating equipment is never boring :)