Graphite Molds or Steel Molds?

Graphite Molds or Steel Molds?

Graphite molds are less common in permanent mold casting than steel molds. Why?

The choice depends on several factors such as material compatibility, durability, and cost.

Material Compatibility

Steel molds are the preferred choice for casting nonferrous alloys such as aluminum (A356) and zinc (ZA5 or ZA12). But, since the mold is made of steel, you cannot use it to cast steel alloys.

Graphite molds can cast carbon steels and low alloy steels.

Durability

Steel molds are high-strength and durable. Steel molds can withstand multiple casting cycles without significant degradation.

Graphite molds are not as durable as steel molds. They degrade more quickly overtime with repeated use. Therefore in high production runs, they must be more frequently replaced than steel molds.

Graphite is also relatively brittle compared to steel. This means graphite molds are more prone to cracking and breaking than steel molds.

Cost

Graphite molds are generally cheaper than steel molds. The exact tooling cost depends on the casting size, complexity, feeding, and material cost.

However, keep in mind the lifespan of each type of mold and production volume. If you have a larger production run, investing in one steel mold may be more cost effective than investing in multiple graphite molds.

Advantages of Graphite Molds

Although less common in permanent mold casting, graphite molds are still used for certain applications.

The most common reason for using a graphite mold instead of a steel mold is in situations where the molten metal would have reacted with a steel mold (e.g. casting steel alloys).

Graphite molds are good for small to medium production runs but must be maintained and replaced as production volume increases (due to lower durability).

Advantages of Steel Molds

Steel molds are often preferred over graphite molds for permanent mold casting.

Steel molds are strong and durable, lasting several casting cycles. The casting is repeatable, with the same dimensional accuracy and high-quality surface finish every time. This makes steel permanent molds ideal for moderate volume production.

At Batesville Products, we use 4140 tool steel for all our permanent molds.

Casting in Steel Molds for 75 Years

Batesville Products is an American foundry, manufacturing custom aluminum and zinc permanent mold castings since 1946.

You bring a design? We’ll handle the tooling, casting, machining, and finishing.

Call 812-537-2275 or email us today!