Hot bend? Cold Bend?

[davygp38]

I have to make two 22.5 degree bends in a piece of 3/16 mild steel to use as a rub rail on some stake pockets I am putting on my flatbed. I just happened to mention it to a friend of mine, and he said " If you can, you should bend it cold." I asked why, and he said that heating it will make it loose strength. In any case I am going to do what I am going to do, which is to bend it cold, if I can ( just so I don't have to drag the torches out.) My dad did a lot of Welding when I was growing up, and he always did what was easiest, Heat things up, or bend them cold, whatever. The question remains, is their any truth to this claim.

 

[deereman75]

If it is a high strength steel, and you dont re-temper it after, it will weaken it. If it is normal mild steel, it will make no diferance what so ever.

 

[JCByrd24]

I will agree and disagree with deereman. If it is high strength/heat treated and you don't repeat whatever process was used, it will weaken it. For normal mild steel though, cold bending is stressing the steel and can be done to the point where it will break. Heating while bending allows the the structure to be more fluid such that it can move and than will re-align in the new position as it cools. For a 22.5 degree bend in 3/16" in mild steel, the difference is probably negligible, but if you are doing it by hand in a vice heat should make it go easier.

 

[davygp38]

Well I ended up using the torches to heat it up. The bends came out sharper with heat and a hammer than with the vise and muscle. I don't think it makes to much of a difference, but when someone disagrees with me, I like to check on it before I really get my back up. thats why I asked.