CNC Machining Material Machinability Chart – Machinability of Metals and Plastics | CNCLATHING


Machinability can help us to determine whether a type of material is suitable for CNC machining services. The machinability rating attempts to quantify the ease of machining of a range of metals. Here CNCLATHING.COM presents the material machinability chart shows the machinability of metals and plastics.

What is Machinability?

Machinability can be defined as the ease of machining of materials, or the ease with which a metal can be cut, depending on the physical properties and cutting conditions of the material. The materials with higher machinability requires less power to cut, can be processed more quickly, and easier to get a good finish.


The American Iron and Steel Institute (AISI) determined the machinability ratings for a wide variety of materials and assigned 160 Brinell B-1112 steel (AISI No.1112 carbon steel) a machinability rating of 100%. The machinability rating is determined by measuring the weighed averages of the normal cutting speed, surface finish, and tool life for each material. Based on the rating of 160 Brinell B-1112 steel, the machinability of metal machinability chart is expressed as a percentage. 

Material Machinability Chart - Machinability of Metals

The metal with a machinability rating smaller than 100% means it is more difficult to machine than B-1112 (carbon steel 1212) and materials with a rating larger than 100% indicates it’s easier to be machined.

Metal Machinability Chart

Here are some tables list the machinability of a wide range of metals. You can check out the steel machinability chart, stainless steel machinability chart, aluminum machinability chart and more in the following contents.

Carbon Steel Machinability Chart  

Alloy Steel Machinability Chart  

Stainless Steels and Super Alloys Machinability Chart 

Tool Steels and Gray Cast Iron Machinability Chart 

Aluminum/Magnesium Alloys Machinability Chart 

Material Machinability Chart - Machinability of Plastics

Unlike metals, the plastic machinability does not measured as percentage, set the plastic machinability index is a nominal ranking out of 20 = best. The machinability of plastics are as below.

Plastic Machinability Chart