Steel alloys are commonly graded by number according to their composition and tensile strength, as laid down by the Society of Automotive Engineers (SAE) in the 1930s.
Alloy 4130 is one of a family of graded steel alloys, formed to SAE specifications. It falls in the 41xx group, where the “4” denotes its primary alloying element of Molybdenum, with the “1” indicating the secondary alloy is Chromium.
This group of steel alloys take the common name of chromoly steels, owing to the combined names of the alloying elements.
The 41xx group of steels are noted for their excellent strength-to-weight ratio. This, combined with their malleability, mean they are particularly suited to use in the automotive industry where they’re popular for roll cages and other applications where structural integrity is crucial.
The 41xx steels are harder and more durable than standard 1020 steels, but are not so easily welded due to the risk of cold cracking. As a consequence, they require before-weld and after-weld thermal treatments to maintain integrity. Done properly, this steel heat treatment imparts supreme resilience to the alloy.
Another characteristic of this group of steels is that they can be case hardened by carburisation of the surface, which provides significant hardening to the outer surface of the product whilst maintaining the internal rigidity.
This provides it with additional strength for uses such as piston pins and gears where aggressive, frictional contact can lead to abrasion.
The 4130 steel product is cold drawn and normalised with a tensile strength of between 85,000 and 110,000 psi. So it’s stretched at room temperature to the desired strength and thickness within the range at which the grade 4130 is applied.
This grade is a particularly popular material in the automotive and aerospace industries due to the relative ease of the welding process compared to other products within the chromoly group, together with its hard-wearing, abrasion-resistive nature.
Readily available in tube, bar, plate, or sheet form, the 4130 product has a range of applications where strength, durability and precision are the key criteria, and where making compromises in those areas brings unnecessary risk.
Uses for 4130 steel alloy are in applications which demand high strength and precision, coupled with low weight and machinability, such as pressurised gas containers, firearm parts, and clutch components.
Much is made of the benefits of the high strength-to-weight ratio of 4130, but steel for such purposes also needs to be readily workable and this is another advantage of this particular alloy.
Because the product is by nature extremely malleable, it’s highly suited to structural tubing where cutting and shaping is necessary without any associated loss in strength.
The smooth finish and resistance to oxidation of this alloy make it particularly appropriate where air resistance needs to be kept to a minimum, such as in aircraft frames, but also for the frames of racing bikes where its high strength-to-weight ratio is also beneficial.
Within the automotive industry, 4130 has gained a reputation as the material of choice for use in the structure of vehicle roll cages, with its application for both internal and external assemblies.
Its characteristics are equally necessary in the aviation industry, where 4130 is widely recognised as an aircraft-quality low-alloy steel. The aviation industry has been an important employer of 4130, with Aerocom Metals first entering the market as a supplier of parts for the fuselage structures of historic aircraft such as Hurricanes and Spitfires.
Indeed, aircraft parts, generally, are a popular use for 4130 where light weight and rigidity are important characteristics. It’s for this reason that 4130 tube is sometimes referred to as “aircraft tubing”, the purpose for which it was originally developed.
As one of the toughest products available, 4130 steel provides the rigidity and corrosion resistance necessary for it to maintain its integrity even when exposed to the elements for prolonged periods and in the harshest of conditions.
Stay strong with the best of British 4130 steel tubing. Call us on +44 (0) 2476 645 551 or get in touch online to talk to one of our sales team.