High Peak Steels supply EN8 engineering steel in both black bar (080M40) and bright bar (080A42). We supply EN8 black in round section in sizes from 25 mm to 500 mm diameter and EN8 bright steel in round section diameters from 5 mm to 150 mm. We also supply EN8 bright steel in square sections in sizes 20 mm to 60 mm.
Please use the enquiry form on this page to request a quotation for EN8 steel.
EN8 is a medium carbon steel which is used in applications where better properties than mild steel are required, at a lower cost than an alloy, making this an excellent alternative to alloy.
This is an unalloyed carbon steel with reasonable tensile strength. Heat treating EN8 engineering steel provides a good surface hardness. It can be flame or induction hardened and is a readily machinable steel.
Although EN8 steel is capable of through hardening by quenching and tempering, it is more commonly supplied in the untreated or normalised condition. It possesses good wear resistance, but reduced weldability.
When heat treated, EN8 offers moderate wear resistance. It shares the same good mechanical properties of EN16 | 605M36T steel which is more resistant to shear loading and frictional wearing. EN8 can be tempered at a heat of between 550 °C to 660 °C, heating for about 1 hour for every inch of thickness before being cooled in oil or water. Normalising of bright Mild Steel takes place at 830-860 °C.
Did you know C45 / C40 are European steel grades offering similar characteristics and suitable for similar applications as EN8.
EN8 steel is suitable for all general engineering applications requiring a higher strength than mild steel. If you are unsure about which is the right steel for a specific application, call 01457 866911 and talk to one of our expert Sales Team.
High Peak Steels stock EN8 round bar, EN8 flat bar and EN8 square bar.
UK Standard EN8 | European Grades C40 / C45 | Werkstoff 1.0511 | SAE/AISI 1040
| Cross section | Product | Min size | Max size |
|---|---|---|---|
 | EN8 round bar | 25mm dia | 800mm dia |
 | EN8 flat bar | ||
 | EN8 square bar | 75mm | 200mm Billet SQ |
 | EN8 hex bar |
| C | Si | Mn | S | P | Cr | Ni | Mo | |
|---|---|---|---|---|---|---|---|---|
| Min | 0.36 | 0.1 | 0.6 | |||||
| Max | 0.44 | 0.4 | 1 | 0.05 | 0.05 | 0.3 | 0.4 | 0.15 |
| Yield N/mm2 | 0.2% proof N/mm2 | UTS (Rm) N/mm2 | Elong (A) % | Red of Area (Z) % | Hardness HB | Impact Test (KV) J |
|
|---|---|---|---|---|---|---|---|
| Normalised (min) | 280 | 550 | 16 | 152 | 16 | ||
| Normalised (max) | 207 | ||||||
| Drawn (min) | 510 | 650 | 8 | ||||
| Drawn (max) | |||||||
| Quenched & Tempered to condition Q (min) | 385 | 625 | 16 | 179 | 28 | ||
| Quenched & Tempered to condition Q (max) | 229 |
| Cross section | Product | Metric sizes Min | Max | Imperial sizes Min | Max |
|---|---|---|---|---|---|
| EN8 round bar | 5mm dia | 200mm dia | 1/4" dia | 8" dia |
| EN8 flat bar | 8mm x 7mm Key Steel | 50mm x 28mm Key Steel | 5/16" x 1/4" Key Steel | 2" x 1 1/2" Key Steel |
| EN8 square bar | 4mm SQ Key Steel | 50mm SQ Key Steel | 3/16" SQ Key Steel | 2" SQ Key Steel |
| EN8 hex bar |
| C | Si | Mn | S | P | Cr | Ni | Mo | |
|---|---|---|---|---|---|---|---|---|
| Min | 0.4 | 0.1 | 0.7 | |||||
| Max | 0.45 | 0.4 | 0.9 | 0.05 | 0.05 | 0.3 | 0.4 | 0.15 |
Mark Thornley, Managing Director of High Peak Steels, shares his extensive knowledge and experience with a question and answer session on EN8 steel…
En8 / 080M40, or C45 as it’s commonly known, is a medium carbon steel, whereas mild steel is a 20 carbon steel. It can be supplied in bright drawn condition, black as rolled or normalised. We stock EN8 from 1/4″ (6mm) diameter to as big as 800 mm diameter and it is normally on the shelf ready to be supplied in random lengths or cut pieces. There is not a lot of difference in price between mild steel and EN8 in rounds, therefore engineers prefer the better properties they get with EN8 and don’t have to pay a whole lot more.
It’s a medium carbon steel, normally >40->45 %. It has a 40 tons tensile strength, it machines well, it can be heat treated (flame or induction hardened). EN8 is suitable for most general engineering applications requiring a higher strength than mild steel.
It is the preferred choice of engineers for being able to offer a higher tensile strength in requirements like axles, gears and shafts which require good wearability.
EN8 represents great value in comparison to alloy engineering steels – probably 50% cheaper – but it still produces a good tensile strength, along with good wearability. So, it has become one of the most popular steel grades to use for economic reasons.
In construction it will be used for buildings, bridges, and heavy duty equipment. In the oil & gas industry it will be used for parts in pressure vessels. In automation and heavy machinery it will be used for gears, shafts, axles, excavation arms in the likes of JCBs, so we sell a lot into the yellow goods markets.
So, you can anneal, flame harden, or heat treat EN8 to obtain a desired tensile strength and hardness. Most of the EN8 we supply will come in the as-drawn state, if it’s bright bar. If it’s black bar, then it’s either in the as-rolled or normalised condition.
The reason for heat treatment would be to refine the microstructure or harden the material to obtain the required yield or tensile strength. By heat treating and refining the material you then get a steel with fewer hard spots and so easier to machine, which helps save costs.
A lot of customers will buy EN8 in a softened state (normalised). They will pre-machine their parts, then send for hardening before they finish machine their components. This reduces the machining costs by working on the softer material before completion.
It offers good wearability. What you get with EN8 is a low cost steel that has good machinability, is heat treatable, possesses decent tensile strength, doesn’t wear out easily and has a great size range and availability. So, a very good practical choice for a lot of different applications.
We stock EN8, 080A42, 080M40, C45. We can do this by refining the steel specification we are ordering from the steel mills. We can order material that will conform to the EN8, 080M40, 080A42, C45, and AISI 4140 by restricting and refining the elements, such as the amount of carbon content allowed.
We do stock EN8 free machining steel in grade 212A42 which has added sulphur content to make it free machining, but this normally only comes in bright bar in rounds and hexagons on a limited size range. We get a lot or repetition machine companies that ask for this because of the amount of machining needed on the finished parts.
We also stock Key Steel in EN8, normally produced in flat and square sizes and in bright bar condition, but with a limited size range available. This material is used to maintain the driving torque between couplings, gears, and sprockets and can also be used with moving shafts and pulleys, mechanical drums, and propellers.
Black rounds: 25mm diameter – 800mm diameter (supplied in cut pieces or full bars).
Bright rounds: 6mm diameter – 200mm diameter, in both metric and imperial sizes.
Flat and square bar, mainly in bright condition but limited size ranges available.
Hexagons in EN8 normally come in the free machining grade 212A42 with the added sulphur for easy machining and limited size range up to 55mm a/f.
Not sure if EN8 or S355 is the best steel for the job? Explore our range of steels by material to get a better understanding of characteristics and applications.
Whatever the sector, we understand the bespoke steel requirements for each application; supplying stock lengths and cut pieces directly to your factory.
Alongside steel supply, we offer a range of steel stockholder services, including bar turning, sawing and precision grinding. We also provide steel hardening and tempering treatments.
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