ASME B18.16.6-2017 pdf download

ASME B18.16.6-2017 pdf download.Prevailing Torque Locknuts (Inch Series).
1 INTRODUCTION 1.1 Scope This Standard covers the complete general, dimen- sional, mechanical, and performance requirements (proof load, prevailing torque, and torque-tension) for carbon steel, inch series nylon insert locknuts of grades N2, N5, and N8 in styles NE ( 1 ⁄ 4 in. to 1 1 ⁄ 2 in.), NTE ( 1 ⁄ 4 in. to 1 1 ⁄ 2 in.), NU ( 1 ⁄ 4 in. to 3 in.), NTU ( 1 ⁄ 4 in. to 3 in.), NM (#2 to #12), NTM (#2 to #12), and hex flange ( 1 ⁄ 4 in. to 3 ⁄ 4 in.). This Standard also includes all-metal hex (#4 to 1 1 ⁄ 2 in.) and hex flange ( 1 ⁄ 4 in. to 3 ⁄ 4 in.) locking nuts of grades A, B, C, F, and G. These nut designs are designated as American National Standards. 1.2 Comparison to ISO Standards There is no ISO inch standard for these products. 2 REFERENCE STANDARDS The following is a list of publications referenced in this Standard. Unless otherwise specified, the reference standard(s) shall be the most recent issue at the time of order placement. ASME B1.1, Unified Inch Screw Threads (UN and UNR Thread Form) ASME B1.3, Screw Thread Gaging Systems for Acceptability: Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ) ASME B1.15, Unified Inch Screw Threads (UNJ Thread Form) ASME B18.2.1, Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series) ASME B18.12, Glossary of Terms for Mechanical Fasteners ASME B18.18, Quality Assurance for Fasteners ASME B18.21.1, Washers: Helical Spring-Lock, Tooth Lock, and Plain Washers (Inch Series) Publisher: The American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016-5990 (www.asme.org) ASTM F436, Standard Specification for Hardened Steel Washers 1 ASTM F606/F606M, Standard Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets ASTM F788, Standard Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series ASTM F812, Standard Specification for Surface Discontinuities of Nuts, Inch and Metric Series ASTM F1137, Standard Specification for Phosphate/Oil Corrosion Protective Coatings for Fasteners ASTM F1470, Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection ASTM F1941/F1941M, Standard Specification for Electrodeposited Coatings on Mechanical Fasteners, Inch and Metric Publisher: American Society for Testing and Materials (ASTM International), 100 Barr HarborDrive, P.O. Box C700, West Conshohocken, PA 19428-2959 (www.astm.org) IFI-101, Torque-Tension Requirements for Prevailing- Torque Type Steel Hex and Hex Flange Nuts Publisher: Industrial Fasteners Institute (IFI), 6363 Oak Tree Boulevard, Independence, OH 44131 (www.indfast.org) SAE J409, Product Analysis — Permissible Variations from Specified Chemical Analysis of a Heat or Cast of Steel Publisher: SAE International,400 CommonwealthDrive, Warrendale, PA 15096-0001 (www.sae.org) 3 TERMINOLOGY Fordefinitionsofterms relatingto fasteners orcompo- nent features thereof used in this Standard, refer to ASME B18.12. 4 DIMENSIONS Unless otherwise specified, all dimensions in this Standard are inches and shall be as specified in the tables and sections 6 through 9. All dimensions apply before coating.
5 NUT DESIGNS AND PROPERTY GRADES 5.1 Nylon Insert Locknuts Nylon insert locknuts are two-piece construction hex nuts and hex flange nuts that derive their prevailing torque characteristics from a full ring of nylon material, located and retained in the nut under its top surface. These are designated in Table 1 as property grades N2, N5, and N8 with hardness requirements in Table 2. The configuration styles are NE (Table 3), NTE (Table 4), NU (Table 5), NTU (Table 6), NM (Table 7), NTM (Table 8), and hex flange (Table 9). 5.2 All-Metal Locknuts All-metal locknuts are one-piece construction hex and hex flange nuts that derive their prevailing torque per- formance from controlled distortion of the nut threads and/or body. Hex locknuts are designated as grades A, B, and C. The dimensions are located in Table 10. Hex flange locknuts are designated as grades F and G. The dimensions are inTable 11. Table 1 identifies the material requirements for the various grades, and Table 2 identi- fies sizes and hardness requirements for the various grades. 6 CORNER FILL A rounding or lack of fill at the location where the hex corners intersect with the chamfer shall be permissible, provided the width across corners is within specified limits in the area extending from a distance equal to 17.5% of the basic thread diameter from the chamfered bearingfaceto 85% ofthe specifiedminimumhexheight. 7 CHAMFERS AND BEARING CIRCLES 7.1 Chamfer Length on Bearing Side of Nuts The length of chamfer at hex corners shall be from 5% to 15% of the nominal thread diameter. The surface of the chamfer may be convex or rounded.