Taylor Special Steels are UK and Ireland stockholders and suppliers of D2 tool steel, also known by its DIN designation 1.2379 (X153CrMoV12) and BS4659 grade BD2. We hold stock in rounds, flats and plate, cut to your required sizes as one-offs or multiple pieces. No order is too large or too small — contact our experienced team for a fast, competitive quote.
D2 is a high-carbon, high-chromium cold-work tool steel containing approximately 12% chromium, giving it exceptional wear resistance and the ability to be air or vacuum hardened with minimal distortion. Its high chromium content places it at the upper end of the cold-work tool steel range, offering superior wear resistance compared to grades such as A2 and O1, while still providing acceptable toughness for many demanding toolmaking applications. D2 is widely used where long tool life in high-volume production is the primary requirement. It achieves a working hardness in the range of 58–63 HRC and can also be used for certain hot-work applications where contact times with the workpiece are short and abrasion resistance is critical.
Related Grades:
A2 Tool Steel (1.2363) | O1 Tool Steel (1.2510) | S1 Tool Steel (1.2550) | H13 Tool Steel (1.2344)
Typical uses of D2 are blanking, moulding, forming, thread rolling and drawing dies, shear blades, gauges and burnishing rolls.
D2 tool steel is widely used across the pressing, forming and manufacturing industries wherever high wear resistance and dimensional stability after hardening are required. Typical applications include blanking dies, forming dies, moulding dies, drawing dies, thread rolling dies, shear blades, gauges, burnishing rolls, trim dies, slitting knives, cold extrusion punches and stamping tooling for high-volume press work.
Equivalent grades and specifications
D2 tool steel is covered by the following international standards and designations:
| Standard | Designation |
|---|---|
| DIN / Werkstoff | 1.2379 — X153CrMoV12 |
| BS4659 | BD2 |
| AISI | D2 |
| ASTM | A681 |
| BS EN ISO | 4957 |
Pack in spent carburising mixture or other inert media in a sealed container to prevent decarburisation and excessive scaling. Heat slowly to 850°C / 880°C and hold at temperature for sufficient time to achieve uniformity. Cool at not faster than 25°C per hour to 650°C and withdraw. Correctly annealed the tools or stock should have a maximum hardness of 241 HB.
Heat to 650°C / 700°C. Hold for 2-4 hours and furnace cool.
Before heat treatment, sufficient machining should be carried out to remove surface decarburisation. Preheat thoroughly at 800°C / 850°C and then raise more rapidly to 1010°C / 1030°C in a controlled atmosphere or, preferably, a neutral salt bath. A useful alternative is box hardening using spent charcoal places away from the working surfaces. The high chromium content of this steel makes reactions sluggish, therefore adequate soaking times must be allowed. Cool in air. D2 may be oil quenched from 970°C / 990°C to give a marked improvement in toughness.
| Temperature | 1010°C / 1030°C air cool | 970°C / 990°C oil quench |
|---|---|---|
| 200°C/210°C | 710-760 HV (60-62 HRC) | 670-735 (59-61 HRC) |
| 240°C/250°C | 670-735 (59-61 HRC) | 650-600 HV (58-56 HRC) |
| 520°C/550°C | 625-735 (57-61 HRC) | 535 -600 HV (52-56 HRC) |
Heat to 200°C / 250°C for a minimum of one hour. A hot air circulation furnace may be used. Tempering within this range will be suitable for most working cold working applications, but not for hot dies, tempering at 520°C / 550°C is recommended.
The diagram illustrates the time required for transformation of austenite to commence and it may be usefully employed in determining the correct temperatures and holding times for interrupted quenching treatments.
(Austenitised at 1010°C)
Taylor Special Steels have been supplying specialist tool steels to UK and Irish industry for over 30 years. All D2 stock is supplied in the annealed condition and available in a wide range of round bar and flat bar sizes, sawn to length to your exact requirements. We supply to the manufacturing, aerospace, automotive and toolmaking industries, from single pieces to bulk orders.
If you need to compare grades, D2 sits at the higher end of the cold-work range. For applications where some toughness can be traded for greater wear resistance, D2 is often the preferred choice over A2 tool steel. For the most demanding high-volume tooling where even greater wear performance is needed, our team can advise on powder metallurgy alternatives. At the other end of the scale, O1 tool steel offers a more economical general-purpose option where extreme wear resistance is not required.
Call us on 0121 552 2741 or email sales@taylorspecialsteels.co.uk to discuss your D2 tool steel requirement.
Related Grades:
A2 Tool Steel (1.2363) | O1 Tool Steel (1.2510) | S1 Tool Steel (1.2550) | H13 Tool Steel (1.2344)