Thread limit refers to a standard notation indicating a level of tolerance for the thread outside the basic thread size of the tap. The limits are identified by a letter "H" for inch or a "D" for metric, followed by a number.
Number of flutes refers to the number of grooves or valleys that are cut into the body of the tap. Higher numbers of flutes increase the strength of the tap and reduce space or chip flow.
Chamfer refers to the length of the tapering threads at the front of the tap. Both the chamfered portion of the tap and the first full thread beyond the chamfer produce the finished thread of the part.
Modified bottoming is similar to bottoming, but the chamfer is longer and has more teeth. They are used for threading blind holes and have 2 to 2-1/2 threads.
Carbon steel is a soft, durable metal. It is commonly used for general purpose applications on abrasive materials, non-ferrous materials, plastics and wood.
Powdered metal cobalt high speed steel provides the highest performance of the powdered metals. It is used at extremely high temperatures and cutting speeds on highly abrasive materials.
Solid carbide provides better rigidity than high speed steel. It is extremely heat-resistant and used for high-speed applications on cast iron, non-ferrous materials, plastics and other tough-to-machine materials.
Vanadium high speed steel (HSSE) is made of high speed steel, carbon, vanadium carbide and other alloys to increase abrasive wear resistance and toughness. It is commonly used on stainless steels and high silicon aluminums.
Finish/Coating
The finish/coating increases productivity, increases tool life and provides the ability to run the tool at higher speeds.
elektraLUBE(R) prevents welding, loading and galling between the tap and the workpiece. It is commonly used on stainless steels, high nickel alloys, aluminum and copper. elektraLUBE(R) is a proprietary coating exclusive to OSG Tap and Die, Inc.
Titanium aluminum nitride (TiAlN) has a higher hardness than TiN and TiCN. It is extremely heat-resistant and used commonly for high-speed applications on stainless steels, nickel alloys and titanium.
TiAlN/TiN is a multilayer coating that combines the high hardness of TiN and the heat resistance of TiAlN. It is commonly used on softer materials in general purpose applications.
Titanium nitride (TiN) is a multi-purpose coating which increases chip flow in softer materials. The heat and hardness resistance allows the tool to run at higher speeds than uncoated tools.
Titanium nitride plus chromium carbide carbon(TM) (TiN+CrC/C) is made of a wear-resistant titanium nitride base and a chromium carbide carbon coating. It is commonly used on ferrous and non-ferrous materials. TiN+CrC/C(TM) is a proprietary coating exclusive to Kennametal, Inc.