1、FORD WORLDWIDE FASTENER STANDARDDate: 1996-10-01Engineering Standards & 1 of 4 Printed copies are uncontrolled .Systems Engineering (ESSE)WE 900Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange Nuts1. SCOPE. This standard covers the general and dimensional requ
2、irements for hexagon (M5 - M24) andflanged hexagon (M5 - M20) prevailing torque nuts.2. REFERENCES.ISO 261 - General purpose metric screw threads - General plan.ISO 965 - General purpose metric screw threads - Tolerances.ISO 1502 - General purpose metric screw threads - Gauging.WE 950 - Prevailing t
3、orque type steel hexagon nuts and hexagon flanged nuts - Mechanicaland performance properties.WE 990 - Surface discontinuities of nuts.WX 100 - Finish Specification3. GENERAL REQUIREMENTS.3.1 DIMENSIONS AND TOLERANCES. The dimensions and tolerances of hexagon and flangedhexagon prevailing torque nut
4、s must be in accordance with Clauses 1 - 6, Tables 1 - 3, and Figures1 and 2.3.2 GAUGING REQUIREMENTS. Prevailing torque nuts must satisfy the gauging requirementsspecified in Appendix A except for the screw thread which must satisfy the requirements of Clause4.3.3 PROTECTIVE FINISH. All dimensions
5、and tolerances defined in this specification apply prior tothe application of the protective finish except where otherwise specified.4. SCREW THREADS.4.1 DIMENSIONS AND TOLERANCES. Screw t hreads, prior to the inclusion of a prevailing torquefeature, must conform to the dimensions and tolerances spe
6、cified in ISO 261 and ISO 965tolerance class 6H.4.2 GAUGING. Nuts shall assemble a minimum of one full turn by hand on a basic GO thread pluggauge before engaging the prevailing torque feature. The gauge must conform to the dimensionsand tolerances defined in ISO 1502 appropriate to the specified th
7、read size and tolerance class.4.3 When coated with organic type coatings tightness to inspec tion gauges may be experienced, seeWX 100.5. FORM AND POSITION TOLERANCES.5.1 CONCENTRICITY OF HEXAGON TO THREAD. The concentricity of the hexagon flats to thethread shall be within the values specified in T
8、able 3.5.2 CONCENTRICITY OF FLANGED PORTION TO THREAD. The concentricity of the outsidediameter 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 surface shall be flat and per pendi
9、cular to the axis of thethread within 1 o .5.3.2 HEXAGON FLANGE NUTS. The bearing surface shall be flat to a maximum of 1.5 oconcave from the plane formed by the bearing circle diameter ( d w ). The plane formed bythe bearing circle diameter shall be perpendicular to the thread within 1 o .5.4 PARAL
10、LELISM OF HEXAGON FLATS TO THREAD. The hexagon flats (measured over theminimum wrenching height m for hexagon nuts or T a for hexagon flanged nuts) must be parallelto the thread within 0.17 x m for hexagon nuts or 0.17 x T a for hexagon nuts.6. SURFACE ROUGHNESS. The surface roughness of the bearing
11、 face shall be evaluated in accordancewith WE 990.FORD WORLDWIDE FASTENER STANDARDDate: 1996-10-01Engineering Standards & 2 of 4 Printed copies are uncontrolled .Systems Engineering (ESSE)WE 900Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange NutsFigure 1. Hex
12、 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 2.5 3s 3) 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 35e 3) Min. 8.79 11.05 14.38 16.64 20.03 23.35 26.75 32.95 39.55h
13、 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 22.8 27.1m 2)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 13.2d w Min. 6.9 8.9 11.6
14、 13.6 16.6 19.6 22.5 27.7 33.2d a 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) Minimu m wrenching height.2) Minimum height of the metal thread.3) May be less than the specified minimum in the area of deformation provided thewrenching height m is maintained.FORD WORLD
15、WIDE FASTENER STANDARDDate: 1996-10-01Engineering Standards & 3 of 4 Printed copies are uncontrolled .Systems Engineering (ESSE)WE 900Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange NutsTable 2. Dimensions of prevailing torque hex flange nutsDimensions in mmN
16、ominal Size M5 M6 M8 M10 M12 M14 M16 M20Pitch 0.8 1 1.25 1.5 1.75 2 2 2.5s 3) Max. 8 10 13 15 18 21 24 30Min. 7.8 9.78 12.73 14.73 17.73 20.67 23.67 29.16e 3) 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 11.1
17、 13.5 16.1 18.2 20.3 24.8m 2)Non-Metallic Insert OnlyMin. 4.7 5.7 7.6 9.6 11.6 13.3 15.3 18.9T a 1) Min. Must satisfy gauging requirements - See Appendixd w Min. 9.8 12.2 15.8 19.6 23.8 27.6 31.9 39.9d c Max. 11.8 14.2 17.9 21.8 26 29.9 34.5 42.8d a Max. 5.75 6.75 8.75 10.8 13 15.1 17.3 21.6Min. 5 6
18、 8 10 12 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 T a is maintained.FORD WORLDWIDE FASTENER STANDA
19、RDDate: 1996-10-01Engineering Standards & 4 of 4 Printed copies are uncontrolled .Systems Engineering (ESSE)WE 900Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange NutsTable 3. Form and position tolerancesDimensions in mmNominal ThreadDiameter dM5 M6 M8 M10M12M14M16M20M24Concentricity -Hexagon Flats toThread0.44 0.54 0.66 0.78Concentricity -Flanged Portionto Thread0.86 1.04 1.24 -NOTE: The dimensions represent Total Indicator Movement.
