FP-96 English Version - Eastern Federal Lands Highway Division

Section 555Receive approval of each assembly (including camber, alignment, accuracyof holes, and fit of milled joints) before reaming is commenced or before anyN/C drilled check assembly is dismantled.(c) Field welded connections. Field welded connections are prohibitedunless specifically shown on the drawings. Verify the fit of members (includingthe proper space between abutting flanges) with the segmentpreassembled.(d) Match marking. Match mark connecting parts preassembled in theshop to assure proper fit in the field. Provide a diagram showing suchmatch-marks.555.16 Connections Using Unfinished, Turned, or Ribbed Bolts. Useunfinished, turned, or ribbed bolts, where specified, conforming to ASTM A307 for grade A bolts. Use bolts with single self-locking nuts or double nuts.Use beveled washers where bearing faces have a slope of more than 1:20 withrespect to a plane normal to the bolt axis.(a) Turned bolts. Furnish turned bolts with a body surface ANSI roughnessnot exceeding 125 microinches. Furnish hex headed bolts and nuts of thenominal size specified. Carefully ream holes for turned bolts and furnishbolts to provide for a light driving fit. Keep bolt threads entirely outside ofthe holes. Provide a washer under the nut.(b) Ribbed bolts. Use approved form of ribbed body with continuous longitudinalribs. Provide a body diameter measured on a circle through thepoints of the ribs 0.08 inches greater than the nominal diameter specifiedfor the bolts.Furnish ribbed bolts with round heads conforming to ANSI B18.5. Furnishhexagonal nuts that are either recessed or have a washer of suitable thickness.Ribbed bolts shall have a driving fit when installed in holes. Providesufficiently hard ribs such that the ribs do not compress or deform and allowthe bolts to turn in the holes during tightening. If the bolt twists beforedrawing tight, ream the hole and provide an oversized replacement bolt.440