SDG 5.5 Minimum Steel Dimensions

5.5 Minimum Steel Dimensions [6.7.3] (01/05) Jan 2005 Deleted reference to one-sixteenth inch material and revised plate thickness for one-eighth and half-inch increments.

A. The following minimum dimensions have been selected to reduce distortion caused by welding and to improve girder stiffness for shipping and handling.

1.) The minimum thickness of plate girder and box girder webs is 7/16-inch.

2.) The minimum flange size for plate girders and top flanges of box girders is 3/4-inch x 12-inches.

3.) The minimum box girder bottom flange thickness is 1/2-inch.

B. Specify flange plate widths and web plate depths in 1-inch increments.

C. Specify plates in accordance with the commonly available thicknesses of Table 5.1.

D. Minimize the different flange plate thicknesses so that the fabricator is not required to order small quantities. See the SDM Chapter 14.

Table 5.1 Thickness Increments for Common Steel Plates
THICKNESS INCREMENT	PLATE THICKNESS
1/8-inch (1/16-inch for web plates)	up to 2-1/2-inches
1/4-inch	> 2-1/2-inches

Structures Design Guidelines	July 2004
5 - Superstructure - Steel

5.5 Minimum Steel Dimensions [6.7.3] (01/05) Jan 2005 Deleted reference to one-sixteenth inch material and revised plate thickness for one-eighth and half-inch increments.

Table 5.1 Thickness Increments for Common Steel Plates