1、 WORLDWIDE FASTENER STANDARD WE920 DIMENSIONAL REQUIREMENTS FOR HEXAGON FLANGE NUTS AND 2016-08-01 HEXAGON FLANGE NUT & CONICAL WASHER ASSEMBLIES Printed copies are uncontrolled. Page 1 of 3 Copyright 2016, Ford Global Technologies, Inc. 1. SCOPE This standard gives the general and dimensional requi
2、rements for hexagon flange nuts and hexagon flange nut & conical washer assemblies - free running and prevailing torque (M5-M20). It was developed to replace the requirements for hexagon flange nut products outlined in WE900, WE901 and WE910. 2. REFERENCES ISO 261 - General purpose metric screw thre
3、ads - General Plan. ISO 965 - General purpose metric screw threads - Tolerances. ISO 1502 - General purpose metric screw threads - Gauging. ISO 4759/1 - Tolerances for fasteners. WE920A - Gauging of hexagon flange and hexagon flange nut & washer assembly WE990 - Surface Discontinuities of Nuts WF900
4、 Dimensional, material requirements and mechanical properties of flat, toothed, conical, bowed and wavy washers WX100 - Finish Specification 3. GENERAL REQUIREMENTS 3.1 DIMENSIONS AND TOLERANCES The dimensions and tolerances of hexagon flange nuts must be in accordance with Sections 1-7, Table 1 and
5、 Figure 1. 3.2 GAUGING (REFEREE METHOD) For referee purposes, dimensions e, mw and c are satisfied if hexagon flange nuts meet the requirements for gauging specified in WE920A. 3.3 PROTECTIVE FINISH All dimensions and tolerances defined in this specification apply prior to the application of the pro
6、tective finish except where otherwise specified. 3.4 MARKING Marking shall be located on the non-bearing face of hexagon flange nuts and shall be either indented or embossed. 4. SCREW THREADS 4.1 DIMENSIONS AND TOLERANCES Screw threads must conform to the dimensions and tolerances specified in ISO 2
7、61 and ISO 965 thread tolerance class 6H. Threads must be cut unless stated otherwise per the utility drawing. Requirement shall be met for prevailing torque type nuts, prior to the inclusion of a prevailing torque feature. WORLDWIDE FASTENER STANDARD WE920 DIMENSIONAL REQUIREMENTS FOR HEXAGON FLANG
8、E NUTS AND 2016-08-01 HEXAGON FLANGE NUT & CONICAL WASHER ASSEMBLIES Printed copies are uncontrolled. Page 2 of 3 Copyright 2016, Ford Global Technologies, Inc. 4.2 GAUGING The gauge must conform to the dimensions and tolerances defined in ISO 1502 appropriate to the specified thread size and class
9、of fit. Prevailing torque type nuts shall assemble a minimum of one full turn by hand on a basic GO thread plug gauge before engaging the prevailing torque feature. When coated with organic type coatings tightness to inspection gauges may be experienced, see WX100. 5. FORM AND POSITION TOLERANCES Th
10、e tolerances of form and position are in accordance with ISO 4759-1, except as stated here within. 5.1 SQUARENESS OF THE BEARING SURFACE TO THE THREAD The bearing surface shall be flat to concave to a maximum of 1.5o from the plane formed by the bearing circle diameter (dw). The plane formed by the
11、bearing circle diameter shall be perpendicular to the thread within 1o. 6. SURFACE DISCONTINUITIES OF NUT Shall be evaluated in accordance with WE990. 7. NUT & WASHER ASSEMBLY 7.1 NUT 7.1.1 RETENTION FEATURE. The nut shall incorporate a feature to retain the washer. The feature shall not protrude be
12、yond the bearing face of the assembled washer. 7.1.2 THREAD COUNTERSUNK. The nut must be countersunk if permitted by the washer retention method or alternatively the retention method must be such that its form facilitates easy assembly of the nut on an external thread. 7.2 WASHER 7.2.1 ASSEMBLY. The
13、 washer component of nut and washer assemblies shall be free to rotate whilst disassembly from the nut is prevented. 7.2.2 FORM AND POSITION TOLERANCES. The form and position tolerances for the washer component shall be in accordance with WF900. 7.2.3 TEST REQUIREMENTS. The washer component of nut a
14、nd washer assemblies shall meet the test requirements specified in WF900, except Section 4.1 Recovery From Compression, prior to assembly except for hardness which must be as specified in WF900 after assembly. 7.2.4 MATERIAL, HEAT TREATMENT AND HARDNESS. The washer component of nut and washer assemb
15、lies shall be Material, Heat Treat & Hardness Class B per WF900. 7.2.5 TYPE. The washer component of nut and washer assemblies shall be conical unless otherwise specified on the Utility Parts drawings. WORLDWIDE FASTENER STANDARD WE920 DIMENSIONAL REQUIREMENTS FOR HEXAGON FLANGE NUTS AND 2016-08-01
16、HEXAGON FLANGE NUT & CONICAL WASHER ASSEMBLIES Printed copies are uncontrolled. Page 3 of 3 Copyright 2016, Ford Global Technologies, Inc. Figure 1. Hexagon Flange nuts Table 1. Dimensions of hexagon flange nuts Dimensions in mm Thread Size M5 M6 M8 M10 M12 M14 M16 M20 Pitch 0.8 1 1.25 1.5 1.75 2 2
17、2.5 c4 min. 1 1.1 1.2 1.5 1.8 2.1 2.4 3 da max. 5.75 6.75 8.75 10.8 13 15.1 17.3 21.6 min. 5 6 8 10 12 14 16 20 dc max. 11.8 14.2 17.9 21.8 26 29.9 34.5 42.8 dw min. 9.8 12.2 15.8 19.6 23.8 27.6 31.9 39.9 e 3 min. 8.79 11.05 14.38 16.64 20.03 23.36 26.75 32.95 m Metallic max. 6.2 7.3 9.4 11.4 13.8 1
18、5.9 18.3 22.4 m Non-Metallic Insert max.min. 7.1 6.52 9.1 8.52 11.1 10.4 13.5 12.8 16.1 15.4 18.2 16.9 20.3 19.0 24.8 22.7 m Free running max.4 5 6 8 10 12 14 16 20 min. 4.7 5.7 7.64 9.64 11.57 13.3 15.3 18.7 s3 max. 8 10 13 15 18 21 24 30 min. 7.78 9.78 12.73 14.73 17.73 20.67 23.67 29.16 mw 1 min.
19、 2.5 3.1 4.6 5.6 6.8 7.7 8.9 10.7 r2) max. 0.3 0.36 0.48 0.6 0.72 0.88 0.96 1.2 1) Minimum wrenching height. 2) Radius r applies both at the corners and at the flats of the hexagon. 3) May be less than specified minimum in the area of prevailing torque deformation provided the wrenching height is maintained. 4) c is measured at dw.
