The Dormer MTT-X E080 powdered-metal steel thread forming tap has a round shank with a square end, diamond-like coating (DLC), and no lubricant grooves, and is used for cold-forming metric right-hand threads in ductile materials such as copper, brass, and aluminum. It is suitable for threading through holes (extending through the workpiece) and blind or bottoming holes (with only one opening). Diamond-like coating (also called amorphous diamond or DLC) is a thin layer of diamond applied to the substrate in non-crystalline form. It reduces friction and abrasion while offering higher hardness properties than titanium aluminum nitride (TiAN) and titanium nitride (TiN). This tap has no grooves so it is suitable for interrupted holes and for through holes in thin sections. Its modified bottoming chamfer has additional length to reduce chip load, adds tool life in difficult-to-machine materials, and permits higher tapping speeds.
Right-hand threads are designed to tighten when a head or nut is rotated clockwise (the most common threading direction). Powdered-metal steel offers performance that approaches that of solid carbide tools but with the toughness and shock-resistance of high-speed steel. The round shank with a square end helps to minimize rotation in the tool holder. This thread forming tap can be used in machines such as drill presses or lathes.
In the Dormer MTT-X E080 series, all taps have modified bottoming chamfers. This tap conforms to ISO 529 standards and can create threads to a depth two-and-a-half times its diameter. It is suitable for the 6HX tolerance class: 6HX exceeds the standard tolerance to increase tool life in tapping high-strength or abrasive materials that do 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.