Guhring - 1/4-28 UNF 3 Flute 3B Modified Bottoming Spiral Flute Tap - Powdered Metal, TiN Finish, 2-1/2" OAL, Right Hand Flute, Right Hand Thread, Series 3999

Modified bottoming chamfers are similar to bottoming chamfers, but they are longer and have more teeth. They are used for threading blind holes and have 2 to 2-1/2 threads.

Powdered Metal (PM) is tougher and more cost effective than solid carbide. It is commonly used on highly abrasive materials including high silicon aluminums.

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.

Fast Spiral Flutes with 40-53 degree angles are suitable for ductile materials like aluminum and copper; medium to high carbon steels and free machining stainless steels.