The Dormer T100/T110 carbide hand threading tap has straight flutes, a round shank with a square end, a modified bottoming chamfer, and a titanium aluminum nitride (TiAlN) coating, and is used to create metric right-hand threads in a range of materials, with best performance in hardened alloy steel. The straight flutes are suitable for threading through holes (extending through the workpiece) and blind or bottoming holes (with only one opening). The TiAlN coating resists heat better than titanium nitride (TiN) and titanium carbon nitride (TiCN) coatings, increasing tool life and performance. It also offers increased hardness compared to TiN and may reduce the need for lubricants based on the application. The modified bottoming chamfer has additional length to reduce chip load, add tool life in difficult-to-machine materials, and permit higher tapping speeds.
Right-hand threads are designed to tighten when the head or nut is rotated clockwise (the most common threading direction). The carbide substrate is harder than high-speed or cobalt steel, making it more wear resistant at high speeds and providing longer tool life. The round shank with square end makes this tap suitable for hand or power-driven applications. This tool can be used in machines, such as drill presses or lathes, or with hand tools such as tap wrenches.
In the Dormer T100 series, all taps have three flutes. In the T110 series, taps with a nominal diameter of 3 mm have four flutes, taps with nominal diameters of 4 mm to 10 mm have five flutes, and those with a nominal diameter of 12 mm have six flutes. All taps in both series have modified bottoming chamfers. This tap conforms to Dormer DIN standards and can create threads to a depth 2 times its diameter. The T100 series is suitable for the 6H tolerance class: 6H is used for a normal length of thread engagement and medium tolerance quality. The T110 series is suitable for the 6HX tolerance class: 6HX exceeds the standard tolerance to increase tool life in tapping high-strength or abrasive materials that rdo not create oversize problems.
Taps produce internal threads in previously formed holes and can be used in machines (such as drill presses) or with hand tools. Common types of taps include hand taps, spiral point taps, spiral flute taps, thread forming taps, and pipe taps. Hand taps (straight-flute taps) collect chips in the straight flutes of the tool; spiral point taps push chips through holes ahead of the tool; and spiral flute taps pull chips back from the tip of the tool, up and out the hole. Thread forming taps, also known as cold forming taps, press rather than cut to create threads in a drilled hole, and no chips are created. Pipe taps create threads in pipes and pipe fittings. Each thread type designates a thread profile and each type is identified with an abbreviation. In the U.S. and Canada, the Unified Thread Standard is the dominant thread type, including UNC (Unified Coarse), UNF (Unified Fine), and NPT (National Pipe Taper) threads, among others.
Precision Dormer manufactures cutting tools under the following brands: Precision Twist, Dormer, and Union Butterfield. The company has locations around the world, and provides tools adhering to ANSI, NAS, and DIN standards.