# Nails and Stress

#### ermines

Guys, why do you think the standard nail is designed with a pointed end and where the top has a cap? What does this imply to the 2 kinds of stress which are normal stress and shear stress? Isn't the pointed end kinda works like a wedge?

Also, why does a homogenous material when broken is always cut at an angle of almost 45 degrees?

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#### FredGarvin

Keep going on the lines of a wedge. A very small area, i.e. a point and a large, sudden force applied =????

In pure axial loading, the 45° plane is the plane where the max shear stress resides.

#### ermines

i kanda understand now the nail part. But about the pure axial loading, i'm still having trouble with it...?

umm, can you somehow give me a starting equation that might explain this and all the necessary conditions needed for this to happen??? :D

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