Titanium Nitride Tap
STEAM TEMPERING & NITRIDING. Nitriding hardens the tap’s surface skin and gives a grey/black appearance. It extends tap life when used on abrasive materials such as Copper, Aluminium alloys and Plastics, but it can make the tap brittle and more prone to breakage. Steam Tempering gives a blue/black finish. It causes minute imperfections on the surface of the tap. These cause the tapping lubricant to be retained more readily, reducing friction and the possibility of cold welding. This helps the tap to cope with both mild and stainless steels. Both above processes are normally only required for Spiral point and Spiral flute taps when the work piece material requires them. These taps are known as ‘Steam tempered and nitrided’ and have a blue/black finish. Titanium nitrided taps. TITANIUM NITRIDE (Tin) This is a gold coloured coating only a few microns thick which is not metallic so reduces the chance of cold welding. It is applied by vapour deposition using special purpose machines. It imparts to the tool a surface hardness of around 80-85 Rockwell. It also imparts a good abrasive resistance and subsequent decrease in friction between the tool and the work piece. This can allow tapping at higher speeds. Suitable for most stainless steels. The process can increase the price of a tap significantly. When the tap is reground the coating will be removed. This coating is more appropriate to Fluteless taps than steam tempering and nitriding. TITANIUM CARBIDE NITRIDING (TiCn) This coating is applied to the tool in the same way as Tin, and gives a silver/grey finish. It has the same qualities as Tin coating, but more so. It is equally more expensive. Suitable for very abrasive and high tensile materials. We would be happy to advise you the best tap and coating for your job.