Posted by fdt860 on December 04, 2021 at 00:36:34 from (90.93.199.3):
In Reply to: Why posted by SVcummins on December 03, 2021 at 22:35:13:
Because the bolt stretch is much more accurate this way.
When you are tightening a bolt, the clamping force is directly proportionnal to the bolt stretch.
When you do torque only, the variables such as amount of oil,under head surface condition, threads conditions and threads fits, give to much uncertainity on the friction factor between the bolt and the parts, and you may end up with different clamping force.
The torque and turn solution also has variables during the first torque sequence, but the torque being smaller, you have less error.
The torque and turn method also allow to have the final tightening right so the bolt is stretched up to the striction point (where it plastically elongates and will not return to initial length). That is the biggest advantage, but also why you never reuse torque and turn bolts.
This allow for very consistent clamping force, because the force does not vary much between beginning of plastic stretching and breakage. That point is totally unobtainable with torque only, because you may break half of the bolts in the head due to uncertainity of the friction factor.
If you reuse the torque and turn bolts, you may stretch them too much this time and go in the breakage zone.
All of the above also explains why the one time use made to stretch bolts have a smaller shank diameter.
Upload one or more videos to your post. Photo and video filesizes should be less than 8MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Third Brush Generators - by Chris Pratt. While I love straightening sheet metal, cleaning, and painting old tractors, I use every excuse to avoid working on the on the electrics. I find the whole process sheer mystery. I have picked up and attempted to read every auto and farm electrics book with no improvement in the situation. They all seem to start with a chapter entitled "Theory of Electricity". After a few paragraphs I usually close the book and go back to banging out dents. A good friend and I were recently discussing our tractor electrical systems when he stated "I figure it all comes back to applying Ohms Law". At this point
... [Read Article]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
