Material Trimming

By ctacker (****)

Date 05-06-2008 21:33

I'm not as good as most at explaining in detail but an example would be:

have you ever seen the sheared edge of a plate thicker than 1/2"? if you have you will see that it kinda looks laminated on the sheared edge.
that edge needs to be trimmed to give a sound edge for welding.

I'll bet Al or someone can explain alot better!

By 803056

Date 05-09-2008 02:38

You're spot on.

When a plate is cut in a shear, the edge of the plate is "damaged". The shear cuts the first half (thickness) of the plate by applying a compressive load much like a power punch, but the bottom half (of the plate thickness) fails in tension and rips the edge leaving torn material. As suggested by CTacker, sound material is aquired by removing the "torn" material by grinding or other means.

Best regards - Al

By hogan

Date 05-09-2008 18:40

would punched holes fall under this also?

By ctacker (****)

Date 05-09-2008 19:14

if it gets welded and is carring a calculated stress on a cyclically loaded structure.
but i make them trim any sheared edge that gets weldedif the plate is thicker than 1/2"

By 803056

Date 05-09-2008 20:40

Hello Hogan;

I've worked on projects where any bolt hole punched through material thicker than 1/2 inch was to be punched or drilled undersized and then reamed. I just took a look at my copy of the New York Steel Construction Manual in which they require bolt holes in primary members to be reamed. So the project I had in mind was most likely a NY bridge job.

As for plug welds and slot weld per D1.1; clause 5.15.3 Material Trimming - it says any sheared edge that will carry a calculated stress and is subject to cyclic stresses has to be trimmed. There is no statement limiting the requirement to butt joins, fillet welds, etc., so I would believe that it applies to punched holes as well as sheared edges since the punch utilizes a shearing force. Maybe someone else can point us in another direction that exempts punched holes for plug welds.

Best regards - Al

By swnorris (****)

Date 05-12-2008 13:10

I've seen structural specs requiring holes to be drilled. I've also seen a structural spec. that didn't permit sheared edges, but that was a very long time ago. That's the only time I've seen that requirement in my 32 years.