Effects of Standoff Tolerances on the Fatigue Life of a Tool-Joint Pin

[+] Author and Article Information
John Finke

Reed Roller Bit Company, Houston, Texas

J. Eng. Ind 88(2), 211-215 (May 01, 1966) (5 pages) doi:10.1115/1.3670930 History: Received July 12, 1965; Online December 08, 2011


A 4 1/2 -in. API full-hole, tool-joint pin is stress-analyzed photoelastically over a range of standoffs. A three-dimensional plastic model is loaded to different values of makeup torque. At each torque a range of cyclic bending loads and a range of cyclic tensile loads are simulated. The results show that makeup torques must be raised for extreme hand-tight, shoulder-gap standoffs if a given pin tension is to be maintained. Maximum static root stresses are shown to be nearly independent of standoff if a constant pin tension is maintained. Further analysis indicates that the fluctuating pin-root stresses are also nearly independent of standoff if complete relieving of the shoulder compression loads is prevented. These considerations indicate that standoff has a negligible effect on the fatigue life of a tool-joint pin if relieving of the joint shoulders under operating conditions is prevented.

Copyright © 1966 by ASME
Your Session has timed out. Please sign back in to continue.






Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In