Standard Tapping Screws - Visual Fastener Guide

Standard Tapping Screws

	TYPE A (ASA-A): A thread forming screw for use in thin metal .015 to .050 thick. Used with drilled, punched out or nested holes in sheet metal, resin impregnated plywood, asbestos combination, and others.

	TYPE B (ASA-B): A thread forming screw for use in heavier metal .050 to .200 thick. Larger root diameter with finer thread pitch for light and heavy sheet metal non-ferrous castings, plastics, impregnated plywood, asbestos combinations, and other materials.

	TYPE AB (ASA-AB): A thread forming screw combining locating type point of Type A with thread size and pitch of Type B. Normal limitations of Type B apply.

	TYPE BP (ASA-BP): Thread forming screw. Same as Type B but has a cone point for use where holes are slightly misaligned. Spaced thread.

	TYPE C (ASA-C): A thread forming screw with either coarse or fine pitch machine screw thread and blunt tapered point. Eliminates chips and permits replacement with standard screw in the field. Higher driving torque required. Usable in heavy sheet metal and die castings.

	TYPE 17 (ASA-17): A thread cutting screw for wood with a coarse tapping screw thread and a special long sharp point fluted to capture chips.

	TYPE U (ASA-U): A thread forming screw with high helix thread for driving or hammering into sheet metals, castings, fiber or plastics for permanent, quick assemblies.

	TYPE 1 (ASA-D): A thread cutting screw with single flute for general use. Produces a fine standard machine screw thread for field replacement.

	TYPE F (ASA-F): A thread cutting screw with machine screw thread with blunt 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.

	TYPE G(ASA-G): Thread cutting. Blunt die point with a single through slot to form two cutting edges. Machine screw threads. For same general use as Type C but where less driving torque is required. For low strength metals and plastics.

	TYPE 23 (ASA-T): A thread cutting screw in the fine thread series offering maximum thread cutting area and excellent chip clearing, with minimum tightening torques.

	TYPE FZ (ASA-BF): A thread cutting screw with a tapping screw thread with blunt tapered point and multi-cutting edges and chip cavities. For plastics, die castings, metal clad and resin impregnated plywoods, and asbestos.

	TYPE 25 (ASA-BT): A thread cutting screw similar to Type 23 point except with coarse Type B thread. For plastics and other soft materials with large chip clearing and cutting edges.