FP-96 English Version - Eastern Federal Lands Highway Division

Section 555Stress relieve members (such as bridge shoes, pedestals, or other parts that arebuilt up by welding sections of plate together) according to Subsection 4.4 ofANSI/AASHTO/AWS Bridge Welding Code D1.5.555.10 Bolt Holes. Punch or drill all bolt holes. Material forming the partsof a member that is composed of not more than 5 thicknesses of metal may bepunched 0.063 inches larger than the nominal diameter of the bolts where thethickness of the material is not greater than 0.75 inches for structural steel,0.63 inches for high-strength steel, or 0.50 inches for quenched and temperedalloy steel, unless subpunching and reaming is required under (h), the preparationof field connections.Where there are more than five thicknesses or where any of the main materialis thicker than 0.75 inches for structural steel, 0.625 inches for high-strengthsteel, or 0.50 inches for quenched and tempered alloy steel, either subdrill andream or drill all holes full size.If required, either subpunch or subdrill (subdrill if thickness limitation governs)0.188 inches smaller and, after assembling, ream 0.063 inches larger ordrill full size to 0.063 inches larger than the nominal diameter of the bolts.(a) Punched holes. Use a die diameter that is not more than 0.063 incheslarger than the punch diameter. Ream holes that require enlarging to admitbolts. Clean cut the holes without torn or ragged edges.(b) Reamed or drilled holes. Ream or drill holes so they are cylindricaland perpendicular to the member. Where practical, direct reamers by mechanicalmeans. Remove burrs on the outside surfaces. Ream and drill withtwist drills, twist reamers, or roto-broach cutters. Assemble and securelyhold together connecting parts that are being reamed or drilled and matchmarkbefore disassembling.(c) Accuracy of holes. Holes not more than 0.031 inches larger in diameterthan the true decimal equivalent of the nominal diameter of the drill or reamerare acceptable. The slightly conical hole resulting from punching operationsis acceptable. The width of slotted holes produced by flame cutting ora combination of drilling or punching and flame cutting shall be no morethan 0.031 inches greater than the nominal width. Grind flame cut surfacessmooth.435