Over thirty years ago, I was involved in the rebuild of a major paper machine. The press section was stainless steel and so were the bolts. I suggested, and my suggestion was followed, that we should use brass nuts on these bolts, for stainless on stainless bolts are known to gall. Further, I suggested, and my suggestion was followed, that a strength of materials calculation should be done and those brass nuts should be lengthened so that they would have enough thread engagement to ensure they had the same holding strength as the stainless nuts they replaced. This was done, too.
These days our sister media company, Paperitalo Publications, has an advertiser "CBG Metal Disintegration and Stud Removal." These fine folks make their living removing stuck bolts and studs. Try them out if you ever have such a problem.
And I am sure you have had or will have such a problem.
But all of this got me to thinking; why do we even use bolts on connections that are regularly disassembled for maintenance? There are plenty of other fasteners schemes and systems that will do the job. In fact, here in the Light Green Machine Institute we highlighted a metal version of "Velcro" years ago.
Has it caught on? Not that I am aware.
And if you think bolts are the only thing that can stand up to the rigors of the heavy loads and vibration we experience, I kindly ask you to stroll out to your local railroad tracks. If they have concrete ties, I'll guarantee the rails are held in place by a little clip that looks like a funny little hairpin.
It is time we did better. And don't worry about putting CBG Metal Disintegration and Stud Removal out of business...we don't innovate that fast in this industry!
Jim Thompson