Custom Die Set FAQs

What is the largest size die set you can make? We can make a die set up to 6 inches in inner diameter, but please be aware that there are many other complexities in making a die set of this size (namely regarding the weight of the die set).

Can you make a die set for larger forces? Yes, we can make a custom die set for any purpose. For hard materials, we can coat with high-hardness TiCN (+50% cost) or manufacture using Tungsten Carbide (+200% cost). For corrosion resistance and for use up to 250°C (482°F), we can make it with 400-series Stainless Steel (+100% cost). Rough prices are given in brackets as a guide. If you have other steels or materials in mind, please let us know. To get a price for your custom die set, please send us an email with your requirements.

Can you make a die set with extra holes for thermocouples, heaters, etc.? Yes, we can. Please note these in a drawing or email with the full dimensions and location.

Can you make vacuum die sets? Yes, we can. Please complete the custom quotation form with your requirements. 

Can you determine the force that my custom die set can take? Unfortunately, no. We are happy to make your custom design and can give some advice, but ultimately the way the die works will be different from our standard die sets. Things like how parallel your press plates are, how evenly the powder is loaded, how a square shape would impact the stress on the walls and corners of the die, and whether there are additional cut-outs all play a part in the modeling required, which would be beyond our scope for each custom die we make. You should make your own investigations. Note that you can make good pellets with relatively low stresses (with respect to steel), you don’t need to push the limits.

My pellets have issues with density — what can I do? Pellet density depends not only on the applied pressure and pressing conditions, but also on the characteristics of the powder itself. Factors such as particle size and grain size distribution play a significant role in how densely the material can compact. We recommend reviewing our pellet preparation guidelines (below) to ensure all best practices are being followed. In some cases, lightly lubricating the die sleeve (for example, with a small amount of WD-40 or similar light lubricant) can help reduce wall friction, allowing particles to rearrange more effectively and potentially improve final pellet density.

Can you supply cold isostatic presses? Yes, we can. If you need a higher density, a more rigid compact for further handling, or better surface contact between materials, consider using cold isostatic pressing (CIP) after making your pellet. Cold Isostatic Presses are available in many materials science departments and through 3rd-party service companies (for larger parts). Alternatively, you can buy a small die that fits inside a normal hydraulic lab press for smaller discs, this is normally a good and cost-effective option. We can make these as well, so send us an email at info@pelletpressdiesets.com if you are interested.

Can I return my custom die set? Custom die sets are only returnable if there is a defect in manufacturing (e.g., if it does not fit together, though this will be checked before it leaves us). We are happy to quote for extra parts if required. We cannot take back your custom die set to make changes once it has been heat-treated. Usually, if you need a design change, it is more cost-effective to remake it.

Can we make spherical pellets? Practically speaking, a perfect sphere is difficult to press with uniaxial pressing for two reasons:

1. Getting the exact amount of powder in your die is challenging.
2. While it is possible to machine very sharp edges, it is not advisable due to the possibility of them coming into contact with each other under high force.

Typically, you would sacrifice a perfectly spherical shape in favor of two small straight sides and two domed surfaces (similar to the shape of a pill). The length of the two straight edges is defined by the amount of powder you use. There are other methods to create spherical shapes, including cold isostatic pressing (CIP), which involves higher die set costs but is entirely possible. Click here if you would like more info on CIPs

 

Designing a Custom Die Set

Wanting to design a product to suit the needs of your project? Take note of the following design considerations before starting:

1. MATERIAL: Do you need to heat or cool your die set? Are you using a force larger than typical? See our material section here to help make your choice.
2. SHAPE: If designing a square or rectangular die set, please consider the additional stresses on the corners when pressing and the need for a larger outer diameter to compensate for the shape.
3. WEIGHT: When designing a very large die set, take into account the weight of the product and its overall usability.
4. HEIGHT: Please consider the height of the pellet you want to press and design your die set around this. Try to keep the amount of unsheathed plunger to a minimum, and consider purchasing multiple plungers at the time of ordering if you need to experiment with pressing. Also, consider the maximum die set height that will fit into your press.
5. TESTING: Perform any stress test calculations on your design to determine the maximum load you can use when pressing. 

Die Set Material Guide

D2 Tool Steel: For most pellets, our standard die sets will be perfect for the job. The die set is heat-treated for high hardness and strength and can be used with the maximum forces listed on our product page. D2 tool steel is a good all-around cold-work die steel with excellent toughness, hardness, and strength upon heat treatment. Therefore, tools and dies made from D2 typically do not scratch, crack, or chip easily.

TICN (Titanium Carbonitride) Coated Steel: TiCN has good adhesion and toughness, as well as a hard, smooth finish that offers improved wear resistance and a lower coefficient of friction than steel on its own. The coating thickness is between 1–4 micrometers and has a dark blue color. It is ideal if you are pressing high-hardness materials such as alumina or zirconia.

400- Series Stainless Steel: For a die set with great corrosion resistance and for those heating their dies up to 250°C (482°F), this is a great choice. Stainless steel is a more expensive starting material and is slower to machine, leading to slightly higher costs than our regular die sets (+100%). Our stainless die sets are heat-treated for high hardness (~HRC 58) and have extremely high strength (120,000 psi). 

Tungsten Carbide: Tungsten carbide offers excellent compressive strength, corrosion resistance, very high hardness, and high-temperature capabilities. For most powder pressing in the lab, it would be overkill, but for certain specialized applications, it can be great. Please note this material is very brittle.

You can find more materials available at the bottom of this page.

Please let us know if you would like a quote for you die set!