Hail resistant steel

[bpeirson]

Is there a minimum gauge thickness that can be relied upon to resist denting by hail. I am thinking about 1" diameter as a maximum.

I searched but most posts are requests for advice on how to fix the dent after it happens. Others are about the Romans ("Hail Caesar").

 

[MikeHalloran]

Well, it depends on thickness, yes, and on yield point and on curvature.

Any car made before 1940 should be satisfactory.

Since that date, for a variety of reasons, cars have gotten lighter and thinner and less curvy, and less hail resistant.

I suppose you could apply a skin of fiberglass and resin. Get some black-dyed fiberglass cloth and the rubes will think it's carbon fiber and think you're a racer.



Mike Halloran
Pembroke Pines, FL, USA

 

[GregLocock]

It's a tradeoff between yield strength and thickness. I can't think of any particular reason why a manufacturer would want a high yield strength skin, as it directly affects the ease with which it can be stamped.

Obviously you could go to a 500 N mm-2 steel, but I'm guessing the resulting panels would be pretty ugly.

Cheers

Greg Locock


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[bpeirson]

Thanks for the input.

We aren't making autobody panels so there are no convoluted designs to stamp. We will be designing panels that will sit on roof tops but the client has specified that the panels should be hail resistant. The shapes will be built up from rectangles and triangles.

 

[GregLocock]

Frankly I'd consider Mike's idea, either a compliant protective layer over the metal, or a stiffner under it.

Or thick aluminium.

Cheers

Greg Locock


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[dgallup]

Something tough, compliant and textured would be perfect. Something like spray on pickup truck bed liner.

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[MikeHalloran]

Big flat tinworks covered with bedliner are still going to show dents.

Covering everything with, e.g. bar grate, will make it hail resistant by most any measure.
... but that brings up a point; How does the customer define 'hail resistant'?

E.g. properly applied urethane paint will still protect the surface even when the surface is dented; would that be sufficient?
Or is the customer willing to pay for armorplate?


Mike Halloran
Pembroke Pines, FL, USA