INFLUENCE OF THREAD LUBRICATION ON THE BEHAVIOR OF HIGH STRENGTH BOLTS

The thread lubricant condition of high strength bolts is important in determining the bolt tensile characteristics. This thesis presents results of tests performed upon 7/8 in. diameter A325 and A490 bolts. The history of the present tightening methods along with the theory relating the torque on the nut to the tension force in the bolt is discussed. The resulting relationship between coefficient of friction and bolt strength is used to explain the behavior of the nut and bolt as the lubrication is varied. Tests were performed upon 79 nuts and bolts to determine the effect of a lubricant. Three types of tests were run: hardness tests, direct tension tersts, and calibration tests. Lubrication was found to influence the maximum clamping force and ductility of the bolts. /Author/

  • Supplemental Notes:
    • Sponsored by Federal Highway Administration.
  • Corporate Authors:

    Engineering Research Institute

    Iowa State University, 104 Marston Hall
    Ames, IA  United States  50010
  • Authors:
    • Eaves, L D
  • Publication Date: 1978-8

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 92 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00300753
  • Record Type: Publication
  • Report/Paper Numbers: CESRL Thesis 78-3
  • Contract Numbers: DOT-FH-11-8900
  • Files: TRIS
  • Created Date: Nov 27 1979 12:00AM