Cast Iron Allowable Stress

[JB23]

Are the cast iron allowable stress factors - 10 for tensile, 6.67 for bending and 5 for compression - set to minimize permanent distortion? The factors for cast iron are considerably greater than those for steel (3.5 currently).

 

[hacksaw]

the design factors have to do with the allowable stresses that the material can safely withstand given normal usuage.

depending on the grade, cast iron can fail abruptly and for this reason is assigned a lower allowable stress than a grade that yields gradually.

There are a couple of good web sites dealing with cast iron. The foundaries are a pretty good source.

you might try the Iron Casting Research organization or the Ductile Iron Institue.