Posted in | Steels

Unalloyed Medium Carbon Steel - EN8 (080M40)

EN8 (080M40) from Thames Stockholders is a general engineering steel that provides customers good all-round performance. It is an unalloyed medium carbon steel that is supplied in bright condition. EN8 (080M40) is commonly used in applications where a higher quality steel is essential when compared to standard mild steel but where costs limit the use of an alloy steel. EN8 also provides good corrosion resistance.

EN8 is an enhanced material grade when compared to EN3B although EN3B’s aesthetic appearance is slightly better after polishing. EN8 (080M40) is a suitable product for loading applications but is not appropriate in shock-resistant applications as the material can shear under challenging conditions.

EN8 (080M40) provides excellent tensile strength when compared to standard bright mild steel which is attained during the thermomechanical rolling process. Additional strength can also be reached by heat treatment – EN8 can be induction or flame hardened but is generally supplied in the normalized or untreated condition. In some countries, EN8 is known as ‘axle steel’ which is one of the steel's core applications.


EN8 is readily machinable although ripping can be a problem during the machining process. It is, therefore, advisable to use a suitable oil lubricant as it is vital to protect the reliability of the material. Ripping of the steel is even more apparent during pitch dry screw cutting. It is recommended to allow 6% of the outer diameter for the elimination of defects in the material’s surface. EN8 does ‘chip’ during the machining process which makes machining quite easy on the whole.


EN8 (080M40) can be easily welded to form a robust joint and since the current product comprises of a lot less carbon than in earlier versions, material up to 18 mm in thickness can be welded. EN8 can also be welded at greater thicknesses than 18 mm, but it would necessitate a pre-heat treatment to stop cracking. Annealing after welding is also suggested to minimize the risk of breaking. TIG and MIG welding are recommended. Similar to all bright drawn engineering steels, EN8 is manufactured to much tighter sectional tolerances when compared to standard mild steel. This means that the product is delivered flatter and straighter than its mild steel equivalents which means it is a lot more economical to machine.


EN8 (080M40) is a general engineering steel and so has a broad range of commercial applications, which include:

  • Hydraulic rams
  • Axles, connecting rods, shafts, and spindles
  • Studs, screws, bolts
  • Automotive and general engineering components

Other Equipment by this Supplier