The Dormer E500/E513 uncoated, high-speed steel three-piece hand threading tap set (including taper, plug, and bottoming chamfers) has straight flutes and round shanks with square ends, and is used to create metric right-hand threads in a range of materials. It is available in two different thread specification standards: Metric Coarse (M) or Metric Fine (MF). The straight flutes are suitable for threading through holes (extending through the workpiece) and blind or bottoming holes (with only one opening).
Right-hand threads are designed to tighten when the head or nut is rotated clockwise (the most common threading direction). High-speed steel (HSS) is a common general-purpose steel for cutting tools and is compatible with a variety of materials. With no coating or surface treatment, this uncoated tool can be used on a broad range of materials and provides an economical alternative to coated tools. The round shank with square end makes it 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 E500/E513 series, E500 taps are available in Metric Coarse (M) sizes; E500 taps with nominal diameters of 1 mm to 1.8 mm have two flutes, taps with nominal diameters of 2 mm to 12 mm have three flutes, taps with nominal diameters of 14 mm to 39 mm have four flutes, and taps with nominal diameters of 42 mm to 56 mm have six flutes. E513 taps are available in Metric Fine (MF) sizes; E513 taps with nominal diameters of 3 mm to 13 mm have three flutes, taps with nominal diameters of 14 mm to 39 mm have four flutes, and taps with nominal diameters of 40 mm to 50 mm have six flutes. This tap set conforms to ISO 529 standards. A tap from this set can create threads to a depth 1 ½ times its diameter. It is suitable for the 6H tolerance class: 6H is used for a normal length of thread engagement and medium tolerance quality.
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.