World Standards Day

World Standards Day

On the 14th October, it is World Standards Day, a day celebrated since 1970. Supported by the main international standards bodies (ISO, IEC and ITU) it is a day in which the importance of standards to global prosperity is celebrated. It is also a day in which tribute is paid to all the thousands of expert volunteers who give up their time to create these voluntary technical agreements.

Is it to spec.; a saying often heard when a part does not fit, or it fails. A standard provides the information on which to judge whether a part is fit for purpose or not. Even though fasteners are standardized products, the central importance of standards are often undervalued. If we go back to before 1840, threaded fasteners were generally bespoke, that is a bolt of a particular size was made to fit a particular nut. Obtain a bolt from some other source, of the same diameter, and the nut was unlikely to fit, and vice-versa. To quote from the paper wrote by Joseph Whitworth in June 1840: On a uniform system of screw threads; "Engineers have adopted their threads without reference to a common standard." Whitworth described his proposed thread in a technical paper since it was before official standards as we know them today. Whitworth's description of his standard thread allowed bolts, and nuts, to be made as standardized products thus allowing taps, dies and gauges to be mass produced for the benefit of all.

Standards tend to develop over time, their content are not fixed forever but tend to be periodically reviewed and if needed, updated, and refined. The Whitworth thread form is defined in the British Standard, BS 84. It's not that the main features of the thread form would change in an update, such as the 55-degree thread angle for example. But rather to extend and refine the standard so that it more precisely defines the product, the thread in this case. For example, for the Whitworth thread, by including tolerances (that Whitworth did not define), by standardising additional thread pitches as well as larger and smaller diameters. The current BS 84 standard, dated 2007, was an update to the 1956 standard that itself was an update to a 1940 standard, and so on back to before the British Standards Institution was formed in 1901 and ultimately back to Whitworth's 1841 paper. This evolution and development of a standard tends to be typical. Even the standard on standards, BS 0, tends to be updated each year.

According to the British Standard 0 (A Standard for Standards), "Standards provide a reliable basis on which common expectations can be shared regarding specific characteristics of product, service or process." Standards in the fastener field tend to be international in nature and are developed on the principle of consensus. The International Organization for Standardization (ISO) produces fastener standards and are based upon collaboration between countries. The organisation was formed in 1947 following a meeting in London on the 14th October 1946, hence the selection of the day. At the international level, a draft standard is produced by experts in the specific field from national standards bodies (such as ANSI, DIN, BS, AFNOR etc.). A consensus is sought first between the experts and then between national standards bodies who, after review and comment, vote whether a particular draft standard should be accepted.

Standards often refer to other standards that in turn, refer to other standards. Take for example, an ISO standard on standard hexagon bolts, ISO 4014. In the standard"s terminology, a bolt would be specified as: Hexagon head bolt ISO 4014 - M12 x 80 - 8.8
o M12 refers to the thread size
o 80 to the length of the bolt, in mm.
o The 8.8 refers to the property class.

Bolt to ISO 4014

You may wish to know the actual dimensions of the thread on the bolt. The ISO 4014 standard tells you that its tolerance class is 6g, but rather than give the dimensions itself, it refers to other standards, ISO 724 and ISO 965-1. The ISO 965-1 standard will tell you that since in the M12 designation and the pitch is omitted, it is a coarse pitch thread and as such, the pitch dimension is listed in ISO 261. This, in turn, will inform you that an M12 coarse pitch is 1.75 mm. The ISO 261 standard itself refers to ISO 68-1 which is foundational in that it defines the shape of the thread. ISO 965-1 will inform you, what in terms of the tolerances the 6 (in the 6g) tolerance grade means and the g tolerance position, from which the actual upper and lower size limits can be obtained. Modern standards are based upon a Russian doll type approach to standardization. In a sense it is not dis-similar to science and mathematics. Core foundational elements and definitions are made that are subsequently built upon.

So, on the 14th October, spare a thought for standards and their importance to fasteners and to the modern world. For more information, have a look at:

More details about World Standards Day

PS Unfortunately, the World Standards Day is not yet fully standardized, in the USA the event will be celebrated on the 13th October. Like standards themselves, it is work in progress.