1、WORLDWIDE FASTENER STANDARDWE 900 2017 11 22. Copyright 2015, Ford Global Technologies, LLC 1 of 4DIMENSIONAL REQUIREMENTS FOR PREVAILING TORQUE TYPE STEEL METRIC HEX NUTS AND HEXFLANGE NUTS 1. SCOPEThis standard covers the general and dimensional requirements for hexagon (M5 - M24) and flanged hexa
2、gon (M5 - M20) prevailing torque nuts. Use for released standard parts only (W5). Not for use with new utility parts (W7).2. REFERENCESISO 261 General purpose metric screw threads - General plan.ISO 965 General purpose metric screw threads - Tolerances.ISO 1502 General purpose metric screw threads -
3、 Gauging.WE 950 Prevailing torque type steel hexagon nuts and hexagon flanged nuts - Mechanicaland performance properties.WE 990 Surface discontinuities of nuts.WX 100 Finish Specification3. GENERAL REQUIREMENTS3.1 DIMENSIONS AND TOLERANCES. The dimensions and tolerances of hexagon and flanged hexag
4、on prevailing torque nuts must be in accordance with Clauses 1 - 6, Tables 1 - 3, and Figures 1 and 2.3.2 GAUGING REQUIREMENTS. Prevailing torque nuts must satisfy the gauging requirements specified in Appendix A except for the screw thread which must satisfy the requirements of Clause 4.3.3 PROTECT
5、IVE FINISH. All dimensions and tolerances defined in this specification apply prior to the application of the protective finish except where otherwise specified.4. SCREW THREADS4.1 DIMENSIONS AND TOLERANCES. Screw threads, prior to the inclusion of a prevailing torque feature, must conform to the di
6、mensions and tolerances specified in ISO 261 and ISO 965 tolerance class 6H.4.2 GAUGING. Nuts shall assemble a minimum of one full turn by hand on a basic GO thread plug gauge before engaging the prevailing torque feature. The gauge must conform to the dimensions and tolerances defined in ISO 1502 a
7、ppropriate to the specified thread size and tolerance class.4.3 When coated with organic type coatings tightness to inspection gauges may be experienced, see WX 100.5. FORM AND POSITION TOLERANCES5.1 CONCENTRICITY OF HEXAGON TO THREAD. The concentricity of the hexagon flats to the thread shall be wi
8、thin the values specified in Table 3.5.2 CONCENTRICITY OF FLANGED PORTION TO THREAD. The concentricity of the outside diameter of the flanged portion to the thread shall be within the values specified in Table 3.5.3 SQUARENESS OF THE BEARING SURFACE TO THE THREAD.5.3.1 HEXAGON NUTS. The bearing surf
9、ace shall be flat and perpendicular to the axis of the thread within 1o.5.3.2 HEXAGON FLANGE NUTS. The bearing surface shall be flat to a maximum of 1.5oconcave from the plane formed by the bearing circle diameter (dw). The plane formed by the bearing circle diameter shall be perpendicular to the th
10、read within 1o.5.4 PARALLELISM OF HEXAGON FLATS TO THREAD. The hexagon flats (measured over theminimum wrenching height m for hexagon nuts or Ta for hexagon flanged nuts) must be parallel to the thread within 0.17 x m for hexagon nuts or 0.17 x Ta for hexagon nuts.WORLDWIDE FASTENER STANDARDWE 900 2
11、017 11 22. Copyright 2015, Ford Global Technologies, LLC 2 of 46. SURFACE DISCONTINUITIES OF NUTSShall be evaluated in accordance with WE 990.Figure 1. Hex nutsTable 1. Dimensions of prevailing torque hex nutsDimensions in mmNominal Size M5 M6 M8 M10 M12 M14 M16 M20 M24Pitch 0.8 1 1.25 1.5 1.75 2 2
12、2.5 3s3) Max.8 10 13 15 18 21 24 30 36Min. 7.8 9.78 12.73 14.73 17.73 20.67 23.67 29.16 35e3) Min. 8.79 11.05 14.38 16.64 20.03 23.35 26.75 32.95 39.55h Max.5.1 6 8 10 12 14.1 16.4 20.3 23.9All Metal Min. 4.8 5.4 7.14 8.94 11.57 13.4 15.7 19 22.6hNon-Metallic InsertMax.6.8 8 9.5 11.9 14.9 17 19.1 22
13、.8 27.1m2)Non-Metallic Insert OnlyMin. 4.4 4.9 6.44 8.04 10.37 12.1 14.1 16.9 20.2m 1) Min. 2.75 3.3 4.4 5.5 6.6 7.7 8.8 11 13.2dw Min. 6.9 8.9 11.6 13.6 16.6 19.6 22.5 27.7 33.2da Max.5.75 6.75 8.75 10.8 13 15.1 17.3 21.6 25.9Min. 5 6 8 10 12 14 16 20 241) Minimum wrenching height.2) Minimum height
14、 of the metal thread.3) May be less than the specified minimum in the area of deformation provided thewrenching height m is maintained.WORLDWIDE FASTENER STANDARDWE 900 2017 11 22. Copyright 2015, Ford Global Technologies, LLC 3 of 4Table 2. Dimensions of prevailing torque hex flange nutsDimensions
15、in mmNominal Size M5 M6 M8 M10 M12 M14 M16 M20Pitch 0.8 1 1.25 1.5 1.75 2 2 2.5s3) Max.8 10 13 15 18 21 24 30Min. 7.8 9.78 12.73 14.73 17.73 20.67 23.67 29.16e3) Min. 8.79 11.05 14.38 16.64 20.03 23.36 26.75 32.95h All Metal Max.6.2 7.3 9.4 11.4 13.8 15.9 18.3 22.4hNon-Metallic InsertMax.7.1 9.1 11.
16、1 13.5 16.1 18.2 20.3 24.8m2)Non-Metallic Insert OnlyMin. 4.7 5.7 7.6 9.6 11.6 13.3 15.3 18.9Ta1) Min. Must satisfy gauging requirements - See Appendixdw Min. 9.8 12.2 15.8 19.6 23.8 27.6 31.9 39.9dc Max.11.8 14.2 17.9 21.8 26 29.9 34.5 42.8da Max.5.75 6.75 8.75 10.8 13 15.1 17.3 21.6Min. 5 6 8 10 1
17、2 14 16 20c Min. 1 1.1 1.2 1.5 1.8 2.1 2.4 3r Max.0.3 0.4 0.5 0.6 0.7 0.9 1 1.21) Minimum wrenching height.2) Minimum height of the metal thread.3) May be less than the specified minimum in the area of deformation provided the wrenching height Ta is maintained.WORLDWIDE FASTENER STANDARDWE 900 2017
18、11 22. Copyright 2015, Ford Global Technologies, LLC 4 of 4Table 3. Form and position tolerancesDimensions in mmNominal Thread Diameter dM5 M6 M8 M10 M12 M14 M16 M20 M24Concentricity -Hexagon Flats to Thread0.44 0.54 0.66 0.78Concentricity -Flanged Portion to Thread0.86 1.04 1.24 -NOTE: The dimensions represent Total Indicator Movement.7 SUMMARY OF REVISIONS2017 11 22 Returned to active status for previously released standard parts. Use WE 955 for new utility parts.2016 08 01 INACTIVE, See WE 920
