There are two main reasons why manganese is the primary choice for wear steel in crusher parts:

1) Manganese steel has the unique ability to work harden as it’s impacted by the mineral crushing process. In addition, the machined surfaces on a crusher casting also work harden as they’re machined. That’s why the machining of manganese steel is avoided by many shops and is considered a specialty process. A new “as cast” crushing surface on a part will begin at near 250 Brinell hardness, and when worn out the same surface may have a hardness value of 350 to 400. I’ve seen returned castings with as high as a 500 hardness value. This would have been accomplished by crushing a very high compressive strength material.

2) Perhaps more importantly, manganese steel is the only steel that will develop this skin hardness and still remain ductile enough below the work-hardened surface to resist breakage. Manganese steel is a very durable material.

We do have pattern equipment to supply a movable jaw die for a 15 x 36 Gruendler jaw crusher.

The jaw die we have the ability to provide features a round tooth form with a 3.000-inch tooth pitch and a 1.000-inch tooth depth. The tooth root lies on the vertical centerline of the part with a full curved jaw side profile. This jaw die is 41.500 inches long and is 36.000 inches wide.

Please check these dimensional values against your existing part and if they match, you can request price and delivery information from our Customer Service Department (1-800-547-9471) for Columbia Part Number 128390.

Your best bet is to contact the National Stone, Sand and Gravel Association in Alexandria, Virginia (800-343-1415) for information on that material spec and where it would be available.

The general conditions we use when applying materials, as you've asked the question, would be:

Manganese is applied in high impact conditions due to its inherent toughness. There are various elemental manganese alloys -- with the higher carbon versions being most suited to high wear conditions -- that balance compression strength and abrasiveness. Higher rates of reduction make manganese the preferred wear material (i.e. 10:1).

I'm unable to respond to the straight "chrome" part of the question. High chrome and ceramic materials are most suited to highly abrasive conditions. The high chrome irons apply to materials with over .4 percent silica content. As that percentage increases, the ceramics become more beneficial. Those materials are considerably less prone to impact resistance, with the high chrome material having a slight edge in impact resistance over the ceramics. In either case these materials are best applied where reduction rates are lessened (i.e. 4:1 in smaller sizes).

There's no one material that's superior -- each has its place.

We're not familiar with that term as a callout for a Cedarapids model jaw crusher. They are specified by feed opening and width dimensions (i.e., a 10x36 model would have a 10-inch feed opening and a 36-inch width). Cedarapids Inc. is located in. Cedar Rapids, Iowa.

However, Universal Engineering made and still does make jaw crushers, and they had a machine specified as a #2. They are also located in Cedar Rapids, Iowa. All that's by coincidence and pretty much a guess on our part. Hope that's some degree of direction for you.