Views
9 years ago

SPRING 2013

  • Text
  • Fastener
  • Fasteners
  • Products
  • Screws
  • Manufacturing
  • Metric
  • Industrial
  • Continued
  • Mechanical
  • Distributors
Distributor's Link Magazine Spring Issue 2013 / VOL 36 / NO.2

38 THE DISTRIBUTOR’S

38 THE DISTRIBUTOR’S LINK Barnaby Myhrum Barnaby Myhrum is an Applications Engineer at Applied Bolting Technology in Bellows Falls, VT. He has over 25 years of experience in engineering and manufacturing companies in roles as an engineer, manager, executive and consultant. He earned a Bachelor of Science in Mechanical Engineering from the University of Vermont, and a Masters of Business Administration from Carnegie Mellon University. He can be reached by email at barnabym@appliedbolting.com. LESSONS FROM THE FIELD: THE PARETO PRINCIPLE AND THE RCSC SPECIFICATION The Research Council on Structural Connections (RCSC) rules the roost in structural bolting. The council consists of qualified structural engineers from academic and research institutions, practicing design engineers, suppliers and manufacturers of fastener components, fabricators, erectors and code-writing authorities. Their publication, “Specification for Structural Joints Using High- Strength Bolts” is THE standard followed in North American steel construction. Applied Bolting has a representative on the council, and we have intimate knowledge of the high-strength bolting sections of the standard. We also travel the world giving highstrength bolting clinics to engineers and iron workers, providing training to first-time users of our Squirter DTIs and troubleshooting problems in the field. It is during this troubleshooting that I have been reminded of the Pareto principle. According to Wikipedia, “The Pareto principle (also known as the 80–20 rule….) states that, for many events, roughly 80% of the effects come from 20% of the causes”. Originally conceived by Vilfredo Pareto, the principle was popularized by quality guru Joseph M. Duran. At Applied Bolting, we observe the principle when troubleshooting problems. Most of the effects come from a handful of causes. The thing is that most of those causes fall into a more general category: lack of familiarity with the RCSC specification. I’m sure that the engineers and designers are well versed in the details of the specification. But this is not always the case with the erectors and ironworkers. I have a theory as to why this is, but here is the point I want to make: significant amounts of time and money could be saved if the people on the ground were required to be conversant with the RCSC specification. ”What Torque Should I Be Using to Install These Bolts” We get this question all the time. The answer is if you are using the calibrated wrench pretensioning method, it depends on the results of the preinstallation verification. One time a caller became irate after hearing this answer. “Why won’t you just tell me what torque to use” It was obvious that he hadn’t performed the pre-installation verification. He didn’t know it was required for pretensioned bolts and therefore didn’t know what it was. He wanted me to tell him what torque to use. The root cause of this serious problem was that he wasn’t conversant with the RCSC specification. Now I’m not saying that everyone must know all 100 pages of the specification by heart. But someone in charge of installing high-strength fasteners should, at a minimum, understand the requirements of: • Section 7: Pre-Installation Verification (four pages with commentary) • Section 8: Installation (eight pages with commentary) • Section 9: Inspection (four pages with commentary) please turn to page 133

SHARE A PAGE FROM THIS MAGAZINE

OPTION 1: Click on the share tab above, or OPTION 2: Click on the icon (far right of toolbar) and then click on the icon (top right of the page).

Copyright © Distributor's Link, Inc. All Rights Reserved | Privacy Policy