Bracket-to-column flange connections shall satisfy the following limitations:
- (1) Column flange fasteners shall be pretensioned ASTM F3125/F3125M Grade A490 or A490M, or ASTM A354 Grade BD bolts or Grade BD threaded rods, and shall conform to the requirements of Chapter 4.
- (2) Column flange bolt holes shall be 1/8 in. (3 mm) larger than the nominal bolt diameter. Bolt holes shall be drilled or subpunched and reamed.
- (3) The use of finger shims on either or both sides at the top and/or bottom of the bracket connection is permitted, subject to the limitations of the RCSC Specification.
- (4) When bolted to a box column, a steel washer plate shall be inserted between the box column and the bracket on both faces of the column. The washer plate shall be ASTM A572/A572M Grade 50 (Grade 345) or better and shall be designed to transfer the bolt forces to the outside edges of the column. Where required, the vertical plate depth may extend beyond the contact surface area by up to 4 in. (100 mm). The plate thickness shall not exceed 3 in. (75 mm). The fasteners shall pass through the interior of the box column and be anchored on the opposite face. The opposite face shall also have a steel washer plate.
- (5) When connecting to the orthogonal face of a box column concurrent with a connection on the primary column face, a 1³/₄ in. (45 mm) steel spacer plate shall be inserted between the beam flanges and the brackets of the orthogonal connection. The spacer plate shall be made of any of the structural steel materials included in the AISG Specification and shall be the approximate width and length matching that of the bracket contact surface area.