From the history of normalization of fasteners concern «Ford»

From the history of normalization of fasteners concern «Ford»

In the early sixties of the XX century the concern «Ford» walked to the need to address the fixture. The importance of this issue the following figures: each year bought only for body attachment 100 million. Bolts, and the total amount of annual purchases amounted to 12-15 billion. All kinds of fasteners, while one passenger car they needed more than 2,500 pieces.

Guidelines Group has been tasked to reduce by at least half the range while improving performance fasteners.

To solve the problem it took a few years of hard work. In this regard, a special committee of the group of fasteners.

The study started with the issue of classification of fasteners for threaded connections. Thus obtained contained a catalog of 11 types of bolts and screws, nuts 11 species, 14 kinds of goals, more than 20 types of other items. In addition, each type of parts has many modifications. In addition to conducting the systematization engineering center was organized poster exhibition of all the samples. Details were also divided into categories: preferred, outdated, obsolete.

In parallel with measures to reduce the range of fasteners is developing new products, which appeared as a result of the company’s standard «UBS» to the patented design of bolted connections. The name is a standard abbreviation of the term «Uniform Bearing Stress», meaning a uniform stress distribution in the mix.

Most bolting seek estimated amount of tightening force of the bolt connection and support this value throughout the life of the product. In many cases, the malleable material on the mating faces under the heads of bolts or nuts for obtaining desired prevents tightening force or leads to the fact that the resultant force then the assembly is lost, leading to a weakening of the connection. By using high-strength bolts and tightening stress, close to the yield point, there is a local malleable material, unless appropriate measures are taken.

One solution to this problem is to use washers under both the bolt head and under nut, but these goals need to be hardened. Adding washers to a compound would increase the overall cost of the fasteners and increase the time required for assembly.

Another possible solution is the use of bolts and nuts with shoulders. In that decision, we chose experts group. For bolts of a new type has been slightly modified standard thread. A characteristic feature of this thread was the presence of the radius of the inner diameter. Introduction of radius a more solid threads with high resistance to fatigue and long life.

Then the concern «Ford» was published guide to the new fasteners for distribution in their own divisions among multiple suppliers.

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