The Chicago-Latrobe 150D series uncoated high-speed steel (HSS), jobber length drill bit and hand tap set with metal case is an 18-piece set for drilling and tapping a variety of inch sizes. The drills have a round shank, the same diameter of the drill size, and the taps have a plug chamfer and a round shank with a square end. The straight flutes of this tap are suitable for threading through holes (extending through the workpiece) and blind or bottoming holes (only one opening). The plug chamfer eases tapping at the beginning of the hole and helps maintain correct perpendicular alignment with the workpiece for increased tool life.

Right-hand threads tighten when a head or nut is rotated clockwise (the most common threading direction). High-speed steel is a general-purpose steel for cutting tools and is compatible with a variety of materials. This uncoated tool can be used on a broad range of materials. The round shank with a square end helps minimize rotation in the tool holder. This tool can be used in drill presses or lathes, or with hand tools such as tap wrenches.

These drill bits have 118-degree conventional point angles for general drilling applications. With a regular (21- to 43-degree) helix angle and uncoated finish, there is efficient chip removal in a variety of materials. Spiral flutes act as a passageway for chip removal from the hole and for coolant to enter the hole. The right-hand twist brings chips up and away from the cutting edge. The Jobber length provides a good compromise of reach versus rigidity.

In the Chicago-Latrobe 150D series, the drill sizes are #36, #29, #25, #21, #7, F, 5/16”, U, and 27/64”. The tap sizes are 6-32 NC, 8-32 NC, 10-24 NC, 10-32 NF, 1/4”-20 NC, 5/16”-18 NC, 3/8”-16 NC, 7/16”-14 NC, and 1/2”-13 NC.

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 (also called straight-flute taps) collect chips in the straight flutes of the tool, spiral point taps push the chips through holes in front 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 Unified Coarse (UNC), Unified Fine (UNF), and National Pipe Taper (NPT) threads.

Greenfield Industries manufactures tools under the brand names Cleveland, Chicago-Latrobe, Cle-Line, Vermont Tap & Die, Bassett, Putnam Tools, Geometric, Vers-O-Tool, H & G, and Acme-Fette. The company, owned by Top-Eastern Group and headquartered in Seneca, SC, makes tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards.