Reynolds 531 (pronounced 'five-three-one') is a

brand name A brand is a name, term, design, symbol or any other feature that distinguishes one seller's good or service from those of other sellers. Brands are used in business, marketing, and advertising for recognition and, importantly, to create an ...

, registered to

Reynolds Technology Reynolds Technology is a manufacturer of tubing for bicycle frames and other bicycle components based in Birmingham, England established in 1898. History The Reynolds Tube Company was founded in 1898 by John Reynolds in Birmingham, England, ...

Birmingham Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1.145 million in the city proper, 2.92 million in the We ...

in the United Kingdom, for a

manganese Manganese is a chemical element with the Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of ...

–

molybdenum Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with lead ...

, medium-carbon

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistan ...

tubing that was used in many quality applications, including race car chassis, aircraft components and, most famously,

bicycle frame A bicycle frame is the main component of a bicycle, onto which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles: a main triangl ...

tubing. It is one of a number of tubing types developed by Reynolds. Reynolds 531 "was the standard of excellence for many decades" among bicycle frame-building materials. And because of the availability of a wide range of butting, diameters and thicknesses of tubes, along with different stays and fork blades, it became the tubing of choice for most frame builders.

Details

Introduced in 1935 and for many years at the forefront of

alloy steel Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low alloy steels and high alloy steels. The differe ...

tubing technology, 531 cycle tubing has been superseded by more complex alloys and heat-treatment/ cold-forming cycles as Reynolds continues to compete with other manufacturers of steel for the bicycle industry.Reynolds Technology FAQ, retrieved 23 October 2011, http://reynoldstechnology.biz/faqs/materials/2 531 tubing became the tubing-of-choice for most framebuilders at least partly because of the huge range of butting, diameters and thicknesses of tubes along with different stays and fork blades available - helped by the willingness of Reynolds to make special tubes for certain manufacturers. Reynolds also made up complete 'sets' of tubing for different cycling applications - for example 531c (Competition), 531st (Special Tourist), 531ATB (All Terrain Bike) and so-on. This flexibility made 531 still competitive even after the introduction of more advanced alloys. The widespread use of TIG and MIG welding in cycle manufacture became a problem as 531 reacted poorly to the higher temperatures produced and 531 has been gradually phased out as a result. The most common like-for-like replacements for 531 are Reynolds 520 and 525 - a Chrome-Molybdenum tubing with very similar characteristics, but in addition to brazing, can also be welded. The 520 tubing can often be seen on modern "fixie" bikes (urban "track" type bike frames), while the 525 with its thicker-walled seat stays is more for cyclo-cross and touring framesets. The approximate alloying composition of 531 tubing is 1.5% Mn, 0.25% Mo, 0.35% C, and is similar to the old British BS970 En 16/18 steel (EN 16 is similar to grade BS970 605M36). Its mechanical properties and response to heat treatment are broadly similar to the AISI 4130 standard alloy steel, also used for bicycle frames, motorcycles, as well as aviation and motor-sport. This material was used to form the front subframes on the

Jaguar E-Type The Jaguar E-Type, or the Jaguar XK-E for the North American market, is a British sports car that was manufactured by Jaguar Cars Ltd between 1961 and 1974. Its combination of beauty, high performance, and competitive pricing established the m ...

of the 1960s. Reynolds 531 is now only available by special order. The nearest available stock material is BS4t45 to Bs5T100 in accordance with BS6S100 conditions.Pro Formance Metals Ltd, http://www.proformancemetals.co.uk (T45) Reynolds has superseded this tube set with a number of innovations such as Reynolds 753 and the more current 853. Reynolds also produces stainless steel tube sets for bicycle frame building - these are 925 and 953.

References

{{Reflist Bicycle parts Steels History of science and technology in the United Kingdom