Type A point: A thread forming screw for use in thin metal .015 to .050 thick. Used with drilled, punched or nested holes in sheet metal,resin impregnated plywood, asbestos combinations, among others. Notrecommended for new design.
Type AB point: A thread forming screw combining locating point of Type A with thread size and pitch of Type B. Normal limitations of typeB apply.
Type B point: A thread forming screw for use in heavier metal .050 to .200 thick. Larger root diameter with finer thread pitch for lightand heavy sheet metal non-ferrous castings, plastics, impregnated plywoods, asbestos combinations, and other materials.
Thread Cutting Screws (Type 1, 17, 23, 25, F)
Type 1 point: A thread cutting screw with single flute for general use. Produces a fine standard machine screw thread for field replacement.
Type 17 point: A thread cutting screw for wood with a coarse tappingscrew thread and a special long sharp point fluted to capture chips.
Type 23 point: A thread cutting screw in the fine thread series offeringmaximum thread cutting area and excellent chip clearing, with minimumtightening torques.
Type 25 point: A thread cutting screw similar to type 23 point exceptwith coarse Type B thread. For plastics and other soft materials withlarge chip clearing and cutting edges.
Type F point: A thread cutting screw with machine screw thread withblunt tapered point, having multi-cutting edges and chip cavities.For heavy gauge sheet metal, aluminum, zinc and lead die castings,cast iron, brass and plastic.
ThreadForming Screws (Type C, CA, Tri-Round, Lo-Driv) & Screws for Plastic (Tri-Round, Round)
Type C point: A thread forming screw with either coarse or fine pitchmachine screw thread and blunt tapered point. Eliminates chips andpermits replacement with standard screw in the field. Higher drivingtorque required. Usable in heavy sheet metal and die castings.
Type CA point: A thread forming screw with either coarse or fine pitchmachine screw thread. Same as Type C except with a Gimlet point. Thelocating point works better than Type C where holes between two adjoiningpieces of sheet metal may be somewhat misaligned.
Tri-Round: A thread forming screw in mostly coarse machine screw threads. Threevertexes perform a roll-forming process to form mating threads.Much better thread forming than Type C or CA, and drives with lesstorque.
Lo-Driv: A thread forming screw in mostly coarse machine screw threads. Thepoint and body design requires low end-load for starting and lowdrive torque for seating. The full 360 degree body above the pointprovides excellent strip-to-drive ratios.