1、 WORLDWIDE FASTENER STANDARD Printed copies are uncontrolled. Copyright 2015, Ford Global Technologies, LLC 1 of 4 WE 900 2015 07 31 Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange Nuts 1. SCOPE. This standard covers the general and dimensional requirements f
2、or hexagon (M5 - M24) and flanged 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 torqu
3、e type steel hexagon nuts and hexagon flanged nuts - Mechanical and performance properties. WE 990 - Surface discontinuities of nuts. WX 100 - Finish Specification 3. GENERAL REQUIREMENTS. 3.1 DIMENSIONS AND TOLERANCES. The dimensions and tolerances of hexagon and flanged hexagon prevailing torque n
4、uts 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 PROTECTIVE FINISH. All dime
5、nsions and tolerances defined in this specification apply prior to the application of the protective finish except where otherwise specified. 4. SCREW THREADS. 4.1 DIMENSIONS AND TOLERANCES. Screw threads, prior to the inclusion of a prevailing torque feature, must conform to the dimensions and tole
6、rances 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 appropriate to th
7、e 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 TOLERANCES. 5.1 CONCENTRICITY OF HEXAGON TO THREAD. The concentricity of the hexagon flats to the thread shall be within the val
8、ues 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 surface shall
9、 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 thread wit
10、hin 1o. 5.4 PARALLELISM OF HEXAGON FLATS TO THREAD. The hexagon flats (measured over the minimum wrenching height m for hexagon nuts or Tafor hexagon flanged nuts) must be parallel to the thread within 0.17 x m for hexagon nuts or 0.17 x Tafor hexagon nuts. 6. SURFACE DISCONTINUITIES OF NUTS. Shall
11、be evaluated in accordance with WE 990. WORLDWIDE FASTENER STANDARD Printed copies are uncontrolled. Copyright 2015, Ford Global Technologies, LLC 2 of 4 WE 900 Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange Nuts Figure 1. Hex nuts Table 1. Dimensions of pre
12、vailing torque hex nuts Dimensions in mm Nominal Size M5 M6 M8 M10 M12 M14 M16 M20 M24 Pitch 0.8 1 1.25 1.5 1.75 2 2 2.5 3 s3)Max. 8 10 13 15 18 21 24 30 36 Min. 7.8 9.78 12.73 14.73 17.73 20.67 23.67 29.16 35 e3)Min. 8.79 11.05 14.38 16.64 20.03 23.35 26.75 32.95 39.55 h Max. 5.1 6 8 10 12 14.1 16.
13、4 20.3 23.9 All Metal Min. 4.8 5.4 7.14 8.94 11.57 13.4 15.7 19 22.6 h Non-Metallic Insert Max. 6.8 8 9.5 11.9 14.9 17 19.1 22.8 27.1 m2)Non-Metallic Insert Only Min. 4.4 4.9 6.44 8.04 10.37 12.1 14.1 16.9 20.2 m 1)Min. 2.75 3.3 4.4 5.5 6.6 7.7 8.8 11 13.2 dwMin. 6.9 8.9 11.6 13.6 16.6 19.6 22.5 27.
14、7 33.2 daMax. 5.75 6.75 8.75 10.8 13 15.1 17.3 21.6 25.9 Min. 5 6 8 10 12 14 16 20 24 1) 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 m is maintained. WORLDWIDE FASTENER STANDARD Pr
15、inted copies are uncontrolled. Copyright 2015, Ford Global Technologies, LLC 3 of 4 WE 900 Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange Nuts Table 2. Dimensions of prevailing torque hex flange nuts Dimensions in mm Nominal Size M5 M6 M8 M10 M12 M14 M16 M20
16、 Pitch 0.8 1 1.25 1.5 1.75 2 2 2.5 s3)Max. 8 10 13 15 18 21 24 30 Min. 7.8 9.78 12.73 14.73 17.73 20.67 23.67 29.16 e3)Min. 8.79 11.05 14.38 16.64 20.03 23.36 26.75 32.95 h All Metal Max. 6.2 7.3 9.4 11.4 13.8 15.9 18.3 22.4 h Non-Metallic Insert Max. 7.1 9.1 11.1 13.5 16.1 18.2 20.3 24.8 m2)Non-Met
17、allic Insert Only Min. 4.7 5.7 7.6 9.6 11.6 13.3 15.3 18.9 Ta1)Min. Must satisfy gauging requirements - See Appendix dwMin. 9.8 12.2 15.8 19.6 23.8 27.6 31.9 39.9 dcMax. 11.8 14.2 17.9 21.8 26 29.9 34.5 42.8 daMax. 5.75 6.75 8.75 10.8 13 15.1 17.3 21.6 Min. 5 6 8 10 12 14 16 20 c Min. 1 1.1 1.2 1.5
18、1.8 2.1 2.4 3 r Max. 0.3 0.4 0.5 0.6 0.7 0.9 1 1.2 1) 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 Tais maintained. WORLDWIDE FASTENER STANDARD Printed copies are uncontrolled. Copy
19、right 2015, Ford Global Technologies, LLC 4 of 4 WE 900 Dimensional Requirements for Prevailing Torque Type Steel Metric Hex Nuts and Hex Flange Nuts Table 3. Form and position tolerances Dimensions in mm Nominal Thread Diameter d M5 M6 M8 M10 M12 M14 M16 M20 M24 Concentricity - Hexagon Flats to Thread 0.44 0.54 0.66 0.78 Concentricity -Flanged Portion to Thread 0.86 1.04 1.24 - NOTE: The dimensions represent Total Indicator Movement.
