WINTER 2014

42 THE DISTRIBUTOR’S

42 THE DISTRIBUTOR’S LINK Industrial Fasteners Institute 636 Oak Tree Blvd. • Independence Ohio 44131 Phone: 216.241.1482 • Fax: 216.241.5901 www.indfast.org CUT THREADS AND ROLLED THREADS MUST MEET THE SAME REQUIREMENTS by Joe Greenslade Director of Engineering Technology, IFI From time to time I get the question, “What are the requirements for inspecting cut threads verses rolled threads” The answer is simple. Threads must meet the same requirements regardless of the way they are produced provided the threaded product standard and/or it’s material standard do not prohibit the use of a particular thread manufacturing method. Following are two examples of standards that prohibit cut threads under certain conditions: 1. SAE J429: Mechanical and Material Requirements For Externally Threaded Fasteners 4.3 Threading Practice Grades 2, 5, 5.2, 8, and 8.2 bolts and screws in sizes up to 3/4 in., inclusive, and lengths up to 6 in., inclusive, shall be roll threaded, except by special agreement. Grade 5.1 sems shall be roll threaded. Threads of all sizes of Grade 1 bolts and screws, and Grades 2, 5, 5.2, 8, and 8.2 bolts and screws in sizes over 3/4 in. and/or lengths longer than 6 in. shall be rolled, cut, or ground, at option of the manufacturer. Threads of all grades and sizes of studs shall be rolled, cut, or ground, at option of the manufacturer. 2. ASTM A574: Alloy Steel Socket Button And Flat Countersunk Head Cap Screws 4.3 Unless otherwise specified, threads shall be rolled for diameters through 0.625 in. and for screw lengths through 4 in. For diameters and lengths other than this, threads may be rolled, cut or ground. Thread Dimensional Requirements: The thread dimensional requirements for internal and external threads are specified in ASME B1.1 for inch threads and ASME B1.13M for metric threads. The metric thread dimensional requirements in B1.13M are identical to those in ISO 68-1, ISO 261, ISO 262, ISO 724, ISO 965 Parts 1, 2, and 3. There is no reference in any of these standards that refer to the method of thread manufacturing. The thread dimensional requirements are independent of the manner in which they are produced. Thread Gage (Gauge) Requirements: In spite of the fact that metric product thread requirements are identical, there are slight differences between ASME B1.16M and ISO 1502 thread gages (gauges in ISO). please turn to page 161