Certain surface treatments for cutting tools can substantially improve the performance of the tools on difficult materials. No single treatment will solve every problem and their use should be restricted to those operations where the extra expense of the treatment can be justified by a substantial performance gain. All treatments are designed to improve performance by increasing tool hardness and wear resistance, reducing cutting friction and torque, inhibiting galling and chip welding, or to improve lubrication. The descriptions listed below will assist you in selecting the most beneficial surface treatment.
TREATMENT  
ALUMINUM TITANIUM NITRIDE (AlTiN)  
DESCRIPTION PERFORMANCE
A black multi-layered coating of Aluminum Titanium Nitride is produced by the physical vapor deposition (PVD) process. The coating is about .0001” thickness and is exceptionally hard (approximately 4400 Vickers hardness). AITiN has a very low coefficient of friction to reduce chip welding and tools can be operated at 25-40% faster feeds and speeds than TiN. AITiN coated tools last up to 1000% longer than TiN coated solid carbide tools when machining hard abrasive materials and high temperature alloys. Can be used for ferrous and non-ferrous metals.
APPLICATIONS PRECAUTIONS
AITiN was designed specifically for use on solid carbide cutting tools to machine hard abrasive materials and hardened steels. It is used for high speed (semi-dry & dry) machining and where higher temperatures are generated. AITiN coated tools oxidize at about 1650°F.

TREATMENT ALSO KNOWN AS
BLACK OXIDE Blue Finish · Steam Finish
DESCRIPTION PERFORMANCE
A black finish is produced by immersing tool in a hot oxidizing salt solution. During this treatment all grinding stresses are relieved to improve toughness of tool. Finish is rust resistant and helps prevent metal to metal contact in machining operations. This finish reduces galling and chip welding and enables tool surface to absorb more lubricant.  
APPLICATIONS PRECAUTIONS
Used for free machining steels, low carbon steels, stainless steels, and ferrous metals (iron based). Black Oxide has tendency to cause galling and chip loading in some non-ferrous applications.

TREATMENT ALSO KNOWN AS
GOLD FINISH Amber Finish · Bronze Finish · Gold Oxide
DESCRIPTION PERFORMANCE
A gold finish is produced by a low temperature heat treatment. During this treatment all grinding stresses are relieved to improve the toughness of the tool. The goal of this heat treatment is identification and sales appeal, not performance. Gold Finish Tools perform the same as Black Oxide or Polished Finish Tools.
APPLICATIONS PRECAUTIONS
Used primarily to identify cutting tools made of cobalt; however, any grade of high speed steel can be "gold" heat treated. Some cutting tools made of high speed steel that have a gold or a gold and black finish are erroneously sold as a premium super steel or even as cobalt.

TREATMENT ALSO KNOWN AS
POLISHED FINISH Bright Finish
DESCRIPTION PERFORMANCE
The polished finish is the result of fine finish grinding and is standard on all ICS cutting tools. While not an actual surface treatment, the smooth surface decreases chip friction and loading.  
APPLICATIONS PRECAUTIONS
Used for non-ferrous and ferrous metals where there is a tendency for chips to cling to surface of cutting tool.  

TREATMENT  
TITANIUM ALUMINUM NITRIDE (TiAlN)  
DESCRIPTION PERFORMANCE
A purple multi-layered coating of Titanium Aluminum Nitride is produced by the physical vapor deposition (PVD) process. The coating is about .0001” thickness and is very hard (approximately 2800 Vickers hardness). TiAIN has a very high oxidation resistance (up to 1500°F) and can be operated at 20-35% faster speeds and feeds than TiN. TiAIN coated tools last up to 1000% longer than TiN when machining abrasive materials such as cast iron. It was designed for very high speed performance.
APPLICATIONS PRECAUTIONS
Used for Titanium and Nickel alloys, stainless steels, hard abrasive materials, and whenever excessive heat is generated on the cutting edge. TiAIN coated tools may have a tendency to gall in aluminum or brass. TiAIN coated tools oxidize at about 1500°F.

TREATMENT  
TITANIUM CARBONITRIDE (TiCN)  
DESCRIPTION PERFORMANCE
A gray multi-layered coating of Titanium Carbonitride is produced by the physical vapor deposition (PVD) process. The coating is about .0001" thickness and is exceptionally hard (approximately 4000 Vickers hardness). TiCN has a very low coefficient of friction to reduce chip welding and tools can be operated at 15- 25% faster feeds and speeds than TiN. TiCN coated tools last up to 300% longer than TiN when machining tool steels and abrasive materials. The performance of TiCN coated HSS tools is comparable to solid carbide tools.
APPLICATIONS PRECAUTIONS
Used for alloy steels, tool steels, and abrasive materials like cast iron and high silicon aluminum alloys. TiCN coated tools may have a tendency to gall in Ni or Ti alloys. TiCN coated tools oxidize at about 750°F.

TREATMENT ALSO KNOWN AS
TITANIUM NITRIDE (TiN) Usually any trade name ending with -Tanium suffix
DESCRIPTION PERFORMANCE
A bright gold coating of Titanium Nitride is produced by the physical vapor deposition (PVD) process. The coating is about .0001" thickness and is approximately Rc80 hardness. It refracts heat and acts as a thermal barrier between the chip and the tool. TiN has a very low coefficient of friction to reduce chip welding and tools can be operated at high speeds and feeds. TiN coated tools last from 200 to 700% longer than uncoated tools. Performance will vary by material and cutting tool. The harder the base material of the tool, the more effective TiN coating will be.
APPLICATIONS PRECAUTIONS
Used for ferrous metals below Rc40 hardness and for non-ferrous metals where increased metal removal rates signify productivity. TiN coated tools have a tendency to gall in Titanium and Titanium alloys. TiN coated tools oxide at approximately 900° F.

TREATMENT ALSO KNOWN AS
ZIRCONIUM COATED (ZrN)  
DESCRIPTION PERFORMANCE
The bright silver/gold coating of Zirconium Nitride is produced by the physical vapor deposition (PVD) process. The coating is about .0001" in thickness and is over 30% harder than TiN (approximately 3100 Vickers hardness). ZrN has more lubricity, improved chemical resistance, and better thermal stability at higher temperatures. ZrN coated tools last from 200 to 1000% longer than uncoated tools and up to 500% longer than TiN when drilling gray iron and brass. Performance will vary by material and tool.
APPLICATIONS PRECAUTIONS
Used for aluminum alloys, cast iron, high temperature alloys, stainless steels, and non-ferrous metals. Also very effective in glass filled plastics and wood. ZrN coated tools oxide at approximately 1100° F.