Almost all D2 tool steel suppliers will claim to manufacture and supply the best quality products at the best price. However, the following questions might make it easier to justify their claim.
Can you precisely explain the chemical composition and its source?
In this regard, you can ask for an MTC or Mill Test Certificate. Optimally, authentic D2 steel would come with:
- Carbon:1.40 to1.60%
- Chromium: 11.00 to13.00%
- Molybdenum: 0.70 to1.20%
- Vanadium: 0.90 to1.10%
Also, check whether the steel is from a secondary re-melter or a primary mill. Usually, the steel obtained from a primary mill offers a relatively more precise and inclusive rating.
Is the steel properly annealed? Can you mention the supply hardness?
In an annealed condition, D2 should offer no more than a hardness of 210-250 HB. Hardness higher than that is likely to burn tools. As a result, you will end up paying extra for machining. This is why it is essential to ask for the hardness report from your D2 steel supplier.
What is the level of inclusion and microstructure?
Conducting the ASTM E45 test is important to check the amount of dirt present inside the steel. Cheap, low-quality D2 indicates more dirt, so it has a lower rating. Such a steel variety is more likely to warp easily. Similarly, good quality D2 has a low rating. Similarly, checking the microstructure is important, as good quality D2 will have finer, roundish and uniformly spread carbides.
What type of hardness is guaranteed post heat treatment?
Standard quality D2 tool steel is likely to attain about 58-62 HRC when it is hardened properly. Hence, it is necessary to ask whether the local D2 tool suppliers offer precise, transparent and practical guidance for heat treatment. You can also ask whether the team maintains an in-house service for the same.
Does the company provide Ultrasonic Tested and certified material?
UT or Ultrasonic Tested materials ensure that the supplied products will have no porosity, internal cracks, or any type of segregation. This aspect is vital, particularly when making dies, large punches, as well as slitting blades.
What forms and sizes do you stock?
Reliable service providers, such as TJKSSL, offer flat bars, Plates, ground flats, round bars and more. Moreover, the premier D2 Tool Steel Suppliers also offer materials of different thicknesses and can also be made to order. Remember that the pricing policy of a supplier who offers ground, flat bars will be different from that of a supplier who makes a cut from a plate.
What is the surface condition and dimensional tolerance?
The most reliable services offer Decarb-free materials, or Decarb having a maximum of 1% of thickness. Again, it is better to avoid the cheaper, hot-rolled D2 steel, as this variety is full of decarb scale and cracks. Cold-rolled steel is a relatively more suitable alternative and more accurate size-wise. Yet, despite being shiny outside, it is not ready to use on all projects. A precision-ground flat stock is a cold-rolled variety and is ideal for dies and punches. Although on the costlier side, it is ideal for heat treatment.
Does it provide services like grinding, cutting, and machining?
A manufacturer that offers value-added services like double-disc grinding, surface grinding, waterjet and laser cutting can help you save both machining time and material wastage.
What are your traceability and certifications?
Look for certifications like full-batch traceability, RoHS, and ISO 9001. Seasoned customers also ask for EN 10204 3.1 certification.
Moreover, if a supplier does not provide at least 2-3 customer references or a hardness report, then it might be better to choose another service.