... National Association of Steel Pipe Distributors, Inc. AMERICAN INSTITUTE OF STEEL CONSTRUCTION 1 - 24 DIMENSIONS AND PROPERTIESCopyright © 1994by American Institute of Steel Construction, Inc.ISBN ... B,U,Y7⁄8B,U,Y3⁄4B,M,U,Y5⁄8B,M,U,Y9⁄16B,M,U,Y1⁄2B,M,S,U,Y7⁄16B,M,U,Y3⁄8B,M,S,U,Y5⁄16M,U,YL5×5×7⁄8B,U,Y3⁄4B,M,U,Y5⁄8B,M,U,Y1⁄2B,M,U,W,Y7⁄16B,M,U,Y3⁄8B,M,U,W,Y5⁄16B,M,U,W,YL4×4×3⁄4M,U,Y5⁄8M,U,Y1⁄2F,M,R,U,W,Y7⁄16F,M,U,Y3⁄8F,M,R,U,W,Y5⁄16F,M,R,U,W,Y1⁄4F,M,R,U,W,Y AMERICAN INSTITUTE OF STEEL CONSTRUCTION 1 - 19Table 1-3 (cont.).Principal Producers of Structural ShapesB—Bethlehem Steel Corp.C—Chaparral Steel F—Florida Steel Corp.I—British Steel M—SMI ... 1-3.Principal Producers of Structural ShapesB—Bethlehem Steel Corp.C—Chaparral Steel F—Florida Steel Corp.I—British Steel M—SMI Steel Inc.N—Nucor-Yamato Steel R—Roanoke Steel S—North Star Steel T—TradeARBEDU—Nucor...