The UN threadform designator was selected as the first two letters of the word UNified. The Unified threadform was developed jointly by the governments of Canada, Great Britain, and the U S A to be an INTERNATIONAL standard that would overcome the logistical problems encountered during World War II created by the non-interchangeability of the U S and British standard threadforms.
Interestingly, ten years after the Unified threadform was introduced, its basic geometry of the Unified threadform was adopted by the International Standards Organation (ISO) as the ISO Metric threadform. Naturally, the Diameters and Pitches of the ISO Metric threads are dimensioned in millimeters rather than inches.
Some decades later, the ISO accepted the Unified threadform as an ISO Standard threadform, under the name ISO Inch.
It's true that many textbooks and other supposedly-reliable references say that the anti-acronym of the UN threadform designation is Unified National, but the originators of the threadform were specific that their intent was replace national-standard threadforms with one Unified international threadform.
Upload one or more videos to your post. Photo and video filesizes should be less than 5MB. 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 - The 8N and the Fox - by Zane Sherman. Dec. 13 1998, Renfroe, Alabama. Last niht I dreamed about the day that I plowed the field of about 10 acres over on what Jimmy and Dandy called the Ledbetter field. I was driving the 1948 8N Ford tractor that Jimmy bought in 48 new This was prebably in about 1951 and maybe even befor the house was built. This would have made me to be about16 years old and I drove the tractor for nothing and would have paid to drive it if I had had any money which I didn't, but neit
... [Read Article]
Latest Ad:
Sell 1958 Hi-Altitude Massey Fergerson tractor, original condition. three point hitch pto engine, Runs well, photos available upon request
[More Ads]
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.