Assigning material cut codes

aPriori requires that each material be assigned a cut code when it is added to a VPE. A material's cut code characterizes the machinability of a material and is adapted from the Sandvik Cormorant cutability classification (CMC code) scheme for metals. Different materials that machine similarly are assigned the same cut code. For example, both Inconel and Hastelloy are assigned a cut code of 20.21, as they are both nickel-based, heat resistant super-alloys.

aPriori uses the cut code to determine the appropriate cutting speed and feed rates for various machining operations, which affects the resulting machining process cycle time, and therefore, the cost of the part.

In some cases, you may want to assign a user-defined cut code instead of a CMC code. Consider, for example, two materials that are assigned the same CMC code, and suppose that you want aPriori to use different cutting speeds or feed rates for each one. In this case, you can assign one of the materials a user-defined cut code and enter custom speed and feed data for that cut code into the appropriate lookup table. See Adding a user-defined cut code on page 1.

If you are not familiar with the Sandvik Cormorant CMC code scheme, you can use this section to help you determine the appropriate cut code for a given material. This section contains the following tables:

• Cut codes reference listing for metals – Defined by Sandvik Coromant for metals

• Cut codes reference listing for plastics – Because Sandvik Coromant does not define cut codes for plastics, aPriori assigns unique cut code values using a similar numbering system

• Cut code by metallurgical category –If you know the metallurgical category, match it to a range of cut codes, and then further refine the cut code by using the Cut codes by example material and Brinell Hardness values table

• Cut codes by example metal material and Brinell Hardness value – If you know the material type and hardness, you can find a similar example material in this table to determine the cut code. Examples listed are for U.S. standards (AISI/SAE). You can find similar tables in other guides for Great Britain, Sweden, Germany, France, Italy, Spain, and Japan.

• Cut codes by example plastic material – If you know the plastic material type, you can find a similar example material in this table to determine the cut code.

• Cut codes by material trade name – If you know the trade name of the material, you may find it in this table, although it contains only a small fraction of existing trade names.

• Cut codes with recommended feeds and speeds – Recommended speed and feed data for both carbide and high-speed steel tools (for drilling with a 1.0” diameter tool). If you know the speed and feed for a material, you can find the corresponding cut code in this table. (aPriori allows you to override the feed and speed for most machining operations if only speed or feed matches the known value.)

• Cut codes with recommended feeds and speeds, relative to mild steel – Recommended speed and feed ratios relative to unalloyed low carbon steel (cut code 1.1). If you know the feed and speed for the material relative to mild steel, you can find the corresponding cut code in this table.

The data in the tables comes from the following sources:

• Machining Data Handbook, Vol. 1, 3rd Edition

• Machining Data Handbook, Vol. 2, 3rd Edition

• Sandvik Coromant (Metric) Rotating Tools, 2002

• Sandvik Coromant (Metric) Turning Tools, 2002