Standard Hooks for #18 Rebar

[ctweaver87]

Are there any codes that prohibit specifying a 180 degree hook for #18 rebar or recommendations against? I have received a recommendation from a fabricator against a 180 degree hook for #18 rebar stating it will put undue stress on the bar, risking breakage.

 

[Archie264]

I heard that they're exceedingly difficult to bend, so much so that if you see them bent it might be reasonable to assume a blowtorch assisted the process, which, of course, reduces its capacity.

 

[TXStructural]

Fabricators should not be using a torch when bending, and I have never seen that done at a reputable shop. The rusty corners are the result of spalling of mill scale and the effect of cold work on the bar, not heat.
The 180 degree is a standard hook, and on a #18, it should be about 2'-4.5" out-to-out. Bending a 180 requires the same forces as bending a 90, since the additional bending is performed on an additional length of bar. The hard part is actually bending a hook that big, and even starting a bend in a bar that big requires very large forces.
(And higher grade bar requires substantially more force.)

 

[frv]

#18 bar? I've only ever heard of those being used in transportation infrastructure. Damn near impossible to splice those things. But in theory, there is no reason you can't hook them, provided you follow the minimum bend diameters for a bar that size.

Heating won't necessarily reduce the strength. You just have to make sure it cools down very slowly. A bar that large, however will have a pretty big quenching effect, so it may be pretty difficult to get it done properly.