1980c3
Mechanical
- Mar 11, 2022
- 19
Hello all,
I have a scenario in which I am tapping m10x1.5 threads into cast iron close to an edge - ~0.120". (imagine a 2x2 that is 6 inches long, with a hole drilled in the end faces off-centered such that the edge of the hole is .120" from the sides).
This distance should not move - it's pretty darn controlled dimensionally.
I am a touch worried about the small remaining wall thickness... I know that there are a few "rules-of-thumb" out there with respect to minimum distance to edge, but they are not always practical and arguably excessive. However, how would I quantify the local peak stresses I would see in the internal threads with a engaged thread length of about 20 mm? these are metric threads so there is no radius callout at the root of the thread, so I'd have to assume something geometrically...
I have tried using FEA, but it's not very clean at all, as you can imagine (levels around 400 ksi σ1 but I am fairly convinced these are just singularities)....
Anyways, any suggestions to what ails me above?
TIA!
I have a scenario in which I am tapping m10x1.5 threads into cast iron close to an edge - ~0.120". (imagine a 2x2 that is 6 inches long, with a hole drilled in the end faces off-centered such that the edge of the hole is .120" from the sides).
This distance should not move - it's pretty darn controlled dimensionally.
I am a touch worried about the small remaining wall thickness... I know that there are a few "rules-of-thumb" out there with respect to minimum distance to edge, but they are not always practical and arguably excessive. However, how would I quantify the local peak stresses I would see in the internal threads with a engaged thread length of about 20 mm? these are metric threads so there is no radius callout at the root of the thread, so I'd have to assume something geometrically...
I have tried using FEA, but it's not very clean at all, as you can imagine (levels around 400 ksi σ1 but I am fairly convinced these are just singularities)....
Anyways, any suggestions to what ails me above?
TIA!