Rolling Punched Angle

[Darken99]

When you roll angle iron does it bend around the centroid or does the roller cause the angle to bend around a different axis? Also is there any way to determine which point it will bend around if there are slotted holes in 10” intervals on the leg out of the roller?

 

[MikeHalloran]

It will certainly narrow the slots, and maybe buckle too, if you're rolling it leg out. That's probably not what you want to happen.



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHalloran]

Oh. Yeah. It bends around the centroid, like always.

There is a third possibility here; it may bent around the centroid of the narrow section inboard of the slots, after the web outboard of the slots fractures.



Mike Halloran
Pembroke Pines, FL, USA

 

[MintJulep]

Wouldn't the centroid be different for a section with a slot and a section without a slot?

 

[IFRs]

My experience is that depending on the roll machine, operator adjustments and amount of oil vs scale on the angle you get some stretch bending and some bending about the centroid. Yes, the centroid is located differently where the slots are. Since is it a little unpredictable, calculate using an average centroid location and them run some test pieces.

 

[berkshire]

Darken99 (Mechanical)
Mike's third possibility would depend on the size of the slot and the amount of metal left outboard of it.
If you are rolling leg out(The easy way.),that leg will mostly be stretched and you may get some reduction in metal thickness at the slots.
B.E.

 

[ornerynorsk]

You will not get a smooth bend on angle with holes punched in it. The angle will have a tendency to bend more at the holes than in the "whole" material. You will get a polygon rather than a radius.

 

[Darken99]

Thanks for all the info guys. I ran a test piece and moved my centroid slightly to compensate for the slots. It came out to the size and matched the hole spacing I was going for. I noticed a bit of reduction around the slots, but nothing that will jeopardize the integrity for which this piece is used.


Thanks again