It is important to ensure you are working with the latest revision. ASME B18.6.4 has undergone several revisions (e.g., 1981, 2002, 2010). Always check the "Date of Issuance" on the cover page of your PDF to ensure compliance with current manufacturing contracts.
One of the most critical aspects of ASME B18.6.4 is the classification of thread types for Tapping Screws.
The ASME B18.6.4 text divides self-tapping and specialized drive screws into three primary functional families: 1. Thread-Forming Tapping Screws
: Dimensions for slotted and recessed drives, including Phillips (Type I), Frearson (Type IA), and Square (Type III) recesses. Appendices : Provide critical engineering data such as: Approximate hole sizes for various materials. Instructions for protrusion and wobble gaging. Formulas used to derive the dimensional tables. The American Society of Mechanical Engineers - ASME Material and Performance Specifications : Commonly manufactured from (quenched and tempered to specific hardness), 300-series stainless steel asme b1864 pdf
A: For education only, some universities post lecture slides with NPT thread dimensions. However, for professional engineering work, there is no legal "free" alternative. ASME copyrights these standards to fund their safety research.
Specifically designed for use in plastic to deform material rather than cut it.
Caution: Avoid using outdated or unauthorized PDF copies, as dimensional requirements for thread forming may change, causing failures in critical assemblies. Common Applications and Types It is important to ensure you are working
Features the same thread pitch as Type B but possesses the gimlet point of Type A. It offers better starting characteristics in thin metal.
To prevent premature mechanical failure, such as hydrogen embrittlement or head shearing, the standard enforces strict metallurgical rules: Property Requirement Carbon Steel Specifications Stainless Steel Options Case-hardened AISI 1016 to 1024 carbon steel Austenitic 18-8 (Type 304) or 316 grades Heat Treatment Liquid quenched and tempered at 650°F (343°C) minimum Solution annealed to maximize corrosion resistance Surface Hardness Rockwell C45 minimum (to penetrate target steels) N/A (Relies on work-hardening characteristics) Core Hardness Rockwell C28 to C38 (maintains structural ductility) Variable based on processing methods Performance Testing Mandates
The primary function of ASME B18.6.4 is to standardise the design and manufacturing requirements for and thread-cutting tapping screws. These fasteners are unique because they eliminate the need for pre-tapped holes, creating their own mating threads as they are driven into materials like metal, plastic, or wood. One of the most critical aspects of ASME B18
Precise head diameter, head height, body diameter, and length requirements.
To find the ASME B18.6.4 standard, which covers "Screws: Tapping and Metallic Drive Screws (Inch Series)," you can access it through the following authoritative channels. Please note that official ASME standards are protected by copyright and generally require a purchase; they are not typically available for free as public PDFs. How to Access ASME B18.6.4 Official ASME Store