UNALLOYED MEDIUM CARBON STEEL
EN8 (080M40) is a general engineering steel which offers customers good all-round performance. Supplied in bright condition, the unalloyed medium carbon steel is typically used in applications where a higher quality steel is required when compared to standard mild steel but where costs prohibit the use of an alloy steel. EN8 also offers good corrosion resistance.
EN8 is an improved material grade when compared to EN3B although EN3B’s aesthetic appearance is slightly better after polishing. EN8 (080M40) is an ideal product for loading applications but is not suitable in shock resistant applications as the material can shear under extreme conditions.
EN8 (080M40) offers superior tensile strength when compared to normal bright mild steel which is achieved during the thermo mechanical rolling process. Extra strength can also be achieved by heat treatment – EN8 can be flame or induction hardened but is normally supplied in the untreated or normalised condition. In certain countries EN8 is referred to as ‘axle steel’ which is one of the steel's main applications.
EN8 is readily machinable although ripping can be an issue in the machining process. It is there recommended that a suitable oil lubricant is used as this essential to protect the integrity of the material. Ripping of the steel is even more evident during pitch dry screw cutting. It is advised to allow 6% of the outside diameter for the removal of defects in the material’s surface. EN8 does ‘chip’ during the machining process which makes machining easier overall.
EN8 (080M40) can be easily welded to form a strong joint and because the current product contains much less carbon than in previous versions, material up to 18mm in thickness can be welded. It is possible to weld EN8 at greater thicknesses than 18mm, but it would require a pre-heat treatment to prevent cracking. Annealing after welding is also recommended to reduce the risk of breaking. Tig and Mig welding is advised. Like all bright drawn engineering steels, EN8 is produced to much tighter sectional tolerances when compared to standard mild steel. This means that the product is supplied straighter and flatter than its mild steel counterparts which means it is much more cost-effective to machine.
EN8 (080M40) is a general engineering steel and therefore has a wide range of commercial applications. Examples include:
- Axles, shafts, connecting rods and spindles
- Hydraulic rams
- Automotive and general engineering components
- Studs, bolts, screws