ASME B18.16.6:2017 pdf download

ASME B18.16.6:2017 pdf download Prevailing Torque Locknuts (Inch Series)
1INTRODUCTION1.1 Scope
This Standard covers the complete general, dimen-sional, mechanical, and performance requirements(proof load, prevailing torque, and torque-tension) forcarbon steel, inch series nylon insert locknuts of gradesN2，N5,and N8 in styles NE (/4 in. to 1hin.),NTE (/4in. to 1/in.),NU (/4 in. to 3 in.), NTU(/4 in. to 3 in.),NM (#2 to #12), NTM(#2 to #12), andhex flange (/4 in. to 34 in.). This Standard also includesall-metal hex (#4 to 1/ in.) and hex flange (/4 in. to /4 in.)locking nuts of grades A,B，C,F,and G.These nutdesigns are designated as American National Standards.1.2 Comparison to lSo Standards
There is no ISO inch standard for these products.
2REFERENCE STANDARDS
The following is a list of publications referenced inthis Standard.Unless otherwise specified, the referencestandard(s) shall be the most recent issue at the time oforder placement.
ASME B1.1,Unified Inch Screw Threads (UN and UNRThread Form)
ASME B1.3，Screw Thread Gaging Systems forAcceptability: Inch and Metric Screw Threads (UN,UNR,UNJ, M, and MJ)
ASME B1.15,Unified Inch Screw Threads (UNJ ThreadForm)
ASME B18.2.1，Square,Hex,Heavy Hex, and AskewHead Bolts and Hex, Heavy Hex, Hex Flange, LobedHead, and Lag Screws (Inch Series)
ASME B18.12,Glossary of Terms for MechanicalFasteners
ASME B18.18,Quality Assurance for Fasteners
ASME B18.21.1,Washers: Helical Spring-Lock,ToothLock, and Plain Washers (Inch Series)
Publisher: The American Society of MechanicalEngineers (ASME),Two Park Avenue, New York,NY 10016-5990 (www.asme.org)
ASTM F436,Standard Specification for Hardened SteelWashers
ASTM F606/F606M，Standard Test Methods forDetermining the Mechanical Properties of Externallyand Internally Threaded Fasteners,Washers,DirectTension Indicators,and Rivets
ASTM F788，Standard Specification for SurfaceDiscontinuities of Bolts,Screws, and Studs, Inch andMetric Series
ASTM F812，Standard Specification for SurfaceDiscontinuities of Nuts, Inch and Metric Series
ASTM F1137,Standard Specification for Phosphate /OilCorrosion Protective Coatings for Fasteners
ASTM F1470,Standard Practice for Fastener Samplingfor Specified Mechanical Properties and PerformanceInspection
ASTM F1941/F1941M,Standard Specification forElectrodeposited Coatings on Mechanical Fasteners,Inch and Metric
Publisher: American Society for Testing and Materials(ASTM International), 100 Barr Harbor Drive, P.O. BoxC700，West Conshohocken,PA19428-2959(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 Variationsfrom Specified Chemical Analysis of a Heat or Castof Steel
Publisher: SAE International,400 Commonwealth Drive,Warrendale, PA 15096-0001 (www.sae.org)
3TERMINOLOGY
For definitions of terms relating to fasteners or compo-nent features thereof used in this Standard, refer toASME B18.12.
DIMENSIONS
Unless otherwise specified, all dimensions in thisStandard are inches and shall be as specified in the tablesand sections 6 through 9.All dimensions apply beforecoating.
5NUT DESIGNS AND PROPERTY GRADES5.1 Nylon Insert Locknuts
Nylon insert locknuts are two-piece construction hexnuts and hex flange nuts that derive their prevailingtorque 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. Theconfiguration 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 andhex flange nuts that derive their prevailing torque per-formance from controlled distortion of the nut threadsand/or body. Hex locknuts are designated as grades A,B, and C.The dimensions are located in Table 10.Hexflange locknuts are designated as grades F and G. Thedimensions are in Table 11. Table 1 identifies the materialrequirements for the various grades, and Table 2 identi-fies sizes and hardness requirements for the variousgrades.
6 CORNER FILL
A rounding or lack of fill at the location where the hexcorners intersect with the chamfer shall be permissible,provided the width across corners is within specifiedlimits in the area extending from a distance equal to17.5% of the basic thread diameter from the chamferedbearing face to 85% of the specified minimum hex height.
7 CHAMFERS AND BEARING CIRCLES
7.1 Chamfer Length on Bearing Side of Nuts
The length of chamfer at hex corners shall be from5% to 15% of the nominal thread diameter. The surfaceof the chamfer may be convex or rounded.
7.2 Bearing Surface Diameter
The diameter of bearing circle on chamfered nuts andwasher-faced nuts shall be within the limits of the maxi-mum width across flats and 95% of the minimum widthacross flats.