BO1 Tool Steel (BS 4659)

We stock BO1 tool steel which is oil-hardened containing chromium, vanadium & tungsten. The steel finds use in various applications, particularly in manufacturing much larger parts.

The material is an excellent general-purpose engineering tool steel. The oil-hardened product gives good wear and abrasion resistance. High hardness is another feature, as well as durability.

  • Press tools, punches, dies and broaches
  • Forming and raising tools where wear resistance is a consideration
  • Tools for woodworking
  • Measuring tools

The product is a cost-effective alternative to high carbon/chromium tool steel, providing enough toughness for various engineering applications. In comparison, high carbon/chromium tool steel is more challenging to machine. With increased hardness, the steel does not require severe quenching - this reduces the risk of cracking and ensures excellent dimensional stability in hardening. An equivalent product grade is 1.2510 steel.

Chemical Composition (weight, %)
* Properties as per BS 4659
C Si P S V Mn Cr W Ni Cu
Min. 0.85 1.10 0.40 0.40
Max. 1.00 0.40 0.035 0.035 0.25 1.35 0.60 0.60 0.40 0.20
BO1 tool steel
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BO1 Tool Steel PDF

The material offers little distortion, retaining its shape after hardening and tempering. Machining BO1 tool steel is good once annealed, with a rating of 90 (compared to 1% carbon steel which has a rating of 100). The grade also retains a good cutting edge.

Welding is possible, but pre-heating is needed to avoid the risk of crack formation. The welding method depends on the use of the material.

As the name suggests, tool steels find use in commercial engineering applications such as tooling and forming.

We stock BO1 tool steel in round and square bars of various diameters. We supply the product in standard lengths or cut to your specific size requirements.

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