Skaggydog

Bolt holes shall comply with the provisions of the RCSC Specification for Structural Joints Using ASTM A325 or A490 Bolts, Section 3.3 except that thermally cut holes shall be permitted with a surface roughness profile not exceeding 1,000 in.
(25 m) as defined in ASME B46.1. Gouges shall not exceed a depth of 1/16 in.(2 mm).

Answer
Although previous specifications limited the methods that can be used, the 2005 AISC specification, Section M2.5, allows the use of any hole-making method that results in a surface roughness not exceeding 1,000 microinches. Most methods can be used to achieve this, including punching, drilling, and thermal cutting with flame and plasma equipment.
Charlie Carter, S.E., P.E.
American Institute of Steel Construction

AISC also used to require the approval of the E.O.R. but a couple three years ago they dropped the Engineer of Records need for approval.

The last is what led us to our purchase of a Robotic Plasma Beam Line from Burlington Automation http://www.pythonx.com

Hope this helps
Marshall

In addition to Waccobird's learned response, let me add that a problem with flame or plasma cut holes is accuracy of diameter.
The AISC code only allows bolt holes to be oversized 1/16" above the bolt dia. It's just plain hard to hand cut a hole that accurately.
A method commonly used for compliance is to flame cut the hole a little undersize, and then use a reamer to both smooth the gouges and to finish the correct dia.

Tim

To add to Wacobird's learned reply, you can get the actual AISC document here:  http://www.pythonx.com/newslinks/useful_links.html