Oversizing holes

[PT999]

Contractor on one of my jobs needed to oversize holes for bolts, and went ahead and burned them out instead of reaming. Is this a reason to reject the connection entirely. I am recommending creating welded connections instead.

 

[JAE]

Either reject the bolted connection or require the use of welding.

 

[dimjim]

What is the bolt size and what is the oversize
diameter? Normally a plus 1/32 is allowed.
If more than that, check with the Engineer in
charge of the job.

 

[lkjh345]

PT999:

I would make the contractor weld the connection. It would be hard to believe that they could accurately flame cut a hole in the field to the tolerances required for bolt connections.

 

[RARWOOD]

Evaluate the application and the applied load. If you are looking at a column base plate your answer would pobably be different than if you are dealing with a shear connection.

It is my understanding that flame cutting holes in the field will reduce the strength of the steel in the area of the hole.

Another problem with misalignment is that they may have the wrong beam in place with the correct beam somewhere else also field modified.

Another option might be to weld reinforcing plates on each side of the flame cut holes and use longer bolts.

 

[Taro]

The RCSC bolt spec allows thermally cut bolt holes if approved by the engineer. Holes for statically loaded connections need not be ground smooth. Holes for cyclically loaded connections must be ground smooth.

The AISC spec permits thermally cut holes if the surface roughness does not exceed 1000 micro-inches.