1、 WORLDWIDE FASTENER STANDARD WE954 Date: 2007-03-01 Printed copies are uncontrolled Copyright 2007, Ford Global Technologies, LLC Page 1 of 6 General Specifications, Assembly Information, Mechanical and Performance Requirements for ISO Metric Threaded Spring Nuts Foreword: Update 2007 March 1stDurin
2、g the March 1st, 2007 update the only change was a cautionary not added to the Scope stating: Nuts of size M10 and larger are unsuitable for clamp load critical applications. WORLDWIDE FASTENER STANDARD WE954 Date: 2007-03-01 Printed copies are uncontrolled Copyright 2007, Ford Global Technologies,
3、LLC Page 2 of 6 General Specifications, Assembly Information, Mechanical and Performance Requirements for ISO Metric Threaded Spring Nuts 1. SCOPE. This standard covers material, heat treatment, and performance of ISO metric threaded spring nuts, in the range M4 to M12 inclusive. NOTE: The design ma
4、y vary between manufacturers provided all requirements of this standard are met. Nuts of size M10 and larger are unsuitable for clamp load critical applications. 1.1 REFERENCES ISO 261 - General purpose metric screw threads - General plan. ISO 683/18 Heat-treated steels, alloy steels and free cuttin
5、g steels-Part 18: Wrought unalloyed steels in the normalized, or normalized and cold-drawn, or hot-rolled and cold-drawn condition. ISO 898-2 - Mechanical properties of fasteners ISO 965-2 - General purpose metric screw threads - Tolerances. WSD-M1A283 (B37/B38/B39/B50/B52) Steel, cross reference st
6、andard parts. W-HTX - Control of Heat Treating Processes and Auxiliary Equipment 2. MATERIAL AND HEAT TREATMENT 2.1 MATERIAL. The material shall be spring steel in accordance with WSD-M1A283-B37/B38/B39/B50/B52. 2.2 HEAT TREATMENT. Austemper to HV420 - 520, Process tests and controls per W-HTX. 2.3
7、IDENTIFICATION. Spring nuts shall be permanently and legibly marked with manufacturers identification. 2.4 THREADS Threads in the extruded barrel shall be roll forming only and shall conform to the basic dimensions and Class 6H tolerances for internal metric screw threads in accordance with ISO 261
8、and ISO 965/2. 2.5 RETAINING EXTRUSION. Retainer formed width shall not exceed the minimum panel hole diameter as specified in Table 1. Retainer bottom leg clearance shall not exceed minimum panel thickness as specified in Table 1 and Figure 1. 2.6 WORKMANSHIP. Nuts shall be free from cracks, splits
9、, burrs, loose scale and any defect(s) that affect fit, form, or function. 2.7 PROPRIETARY VARIATIONS. Design of retaining feature(s) and other dimensional details of parts produced by individual manufacturers may vary within envelope dimensions given, provided all requirements of this specification
10、 are met. 3. PERFORMANCE. 3.1 INSTALLATION. Spring nuts shall be designed to minimize required installation force to application panels. As applications vary considerably, maximum installation force specification shall be designated by individual spring nut design releases. Forces for installation s
11、hall be 55N maximum for 6mm and smaller spring nuts, and 90N maximum for 8mm through 12mm sizes on the following installation force test panel: Unless otherwise specified, installation force test panels shall be constructed of WSD-M1A283-B52 or equivalent steel, smooth (Ra 2.5m) hardened to HV613-65
12、3, have a thickness of the maximum application panel, and have an edge radius per Table 2. Installation forces shall be applied at a travel rate of 4 1mm/second via a testing setup per Figure 2. WORLDWIDE FASTENER STANDARD WE954 Date: 2007-03-01 3.2 RETENTION. Spring nuts shall be assembled onto tes
13、t panels of the specified minimum application panel thickness, having minimum diameter holes located at their maximum recommended edge distance, per Table 1. The retaining feature shall locate in the hole and pull force of 13N minimum shall be required to remove the nut from the test panel. Pull for
14、ces shall be applied through the throat area of the nut and at a travel rate of 4 1mm/second via a testing setup per Figure 3. 3.3 STRENGTH. Spring nuts shall be prepared for testing by removing the lower leg and fold portion at the rear as depicted by Figure 4. The nut, along with its test bushings
15、, shall be assembled to the test bolt (Figure 4) then installed to a tension test fixture. Test bushing shall be hardened to HV674-746 and conform to dimensions shown in Table 3. Load shall be applied at a maximum travel rate of 25mm/minute. 3.3.1 SLEEVE HEIGHT DEFORMATION. The actual sleeve height
16、“A“ (Figure 1) shall be measured and recorded. The leg containing the threaded extrusion shall be assembled onto the test bolt, as shown in Figure 4, then installed into a suitable tension test fixture. A tension load shall be applied to this assembly equal to the value shown in Table 4 for the appr
17、opriate thread diameter. Once this load is obtained, the load shall be released, the test bolt removed, and dimension “A“ recorded again. The maximum permanent sleeve height set is obtained by subtracting the original sleeve height dimension from the final sleeve height dimension. This amount may no
18、t exceed the value specified in Table 4. 3.3.2a PROOF LOAD, FREE-RUNNING SPRING NUTS. A tension load equal to the proof load specified by Table 5 shall be applied to the spring nut through the test bolt. The nut shall resist this proof load without failure by rupture, collapse, cracking, or thread s
19、tripping, and the test bolt shall be removable from the nut by the fingers after the proof load is released. (NOTE: Occasionally it may be necessary to use a manual wrench or other means to start the bolts motion. Use of such means is permissible provided the bolt is removable by the fingers followi
20、ng initial loosening of not more than one-half turn of the bolt.) 3.3.2b PROOF LOAD, PREVAILING TORQUE SPRING NUTS. A tension load equal to the proof load specified by Table 5 shall be applied to the spring nut through the test bolt. The nut shall resist this proof load without failure by rupture, c
21、ollapse, cracking, or thread stripping. The test bolt shall be removable from the nut with a torque not to exceed the specified maximum first-on value. 3.4 TEST BOLTS. Test bolts shall be of ISO metric coarse thread form as specified in ISO 261 and ISO 965 and shall be Property Class 12.9. Test bolt
22、s shall be surface coated with any suitable finish and the thread shall meet the requirements of a 6g tolerance class after coating. Figure 1 Printed copies are uncontrolled Copyright 2007, Ford Global Technologies, LLC Page 3 of 6 WORLDWIDE FASTENER STANDARD WE954 Date: 2007-03-01 Table 1. Test pan
23、el Nominal thread size (mm) Min. test panel thickness .13mm Min. test panel hole dia. .25mm Test panel edge distance to hole .25mm Max M4 0.60 7.5 M5 0.60 8.3 0.75 * B M6 0.80 9.9 Where B is the M8 0.80 11.3 throat depth M10 1.50 14.7 of the spring nut M12 1.50 17.3 (FIG. 1) Figure 2 INSTALLATION FO
24、RCE Table 2 Test Panel Thickness (mm) Test Panel Edge Radius (mm) 0.600 - 1.139 0.13 - 0.25 1.140 - 2.999 0.25 - 0.51 3.000 - 8.500 0.76 - 1.27 Figure 3 RETENTION FORCE Printed copies are uncontrolled Copyright 2007, Ford Global Technologies, LLC Page 4 of 6 WORLDWIDE FASTENER STANDARD WE954 Date: 2
25、007-03-01 Test Bushing and Table 3 Figure 4 Table 4 Nominal thread Size (mm) Permanent set Tensions test load (kN) Permanent set Allowed max (mm) M4 M5 M6 M8 M10 M12 5250 9110 12900 23850 37540 55650 0.25 0.25 0.38 0.51 0.64 0.76 Table 5 Nominal thread Size (mm) Proof load - min (N) + 1%/-0 M4 M5 M6
26、 M8 M10 M12 7000 12140 17200 31800 50050 74200 Printed copies are uncontrolled Copyright 2007, Ford Global Technologies, LLC Page 5 of 6 WORLDWIDE FASTENER STANDARD WE954 Date: 2007-03-01 Recommended Assembly Data Nut Size Style A Edge Distance B Panel Hole Diameter C Nut Length Clearance D Slot or
27、Emboss Width E Emboss Depth F Emboss Depth Max Min Max Min Min1Max Min Min1Min1M4x0.7 Short 9.0 8.0 8.3 7.5 18.0 15.0 14.0 2.5 1.0 Long 13.0 12.0 23.0 M5x0.8 Short 10.5 9.5 9.1 8.3 20.5 16.0 15.0 2.5 1.1 Long 15.5 14.5 26.5 M6x1 Short 12.5 11.5 10.7 9.9 25.0 16.5 15.5 2.5 1.2 Long 18.5 17.5 31.5 M8x
28、1.25 Short 13.5 12.5 12.1 11.3 26.5 20.0 19.0 2.5 1.4 Long 20.0 19.0 33.5 M10x1.5 Short 17.5 16.5 15.5 14.7 35.0 26.0 25.0 3.0 2.0 Long 27.5 26.5 45.0 M12x1.75 Short 22.5 21.5 18.3 17.3 43.5 33.0 32.0 3.2 2.2 Long 32.5 31.5 53.5 1Consideration should be given to tolerance of manufacturing practices used to emboss and punch these features when designing panels in which they are employed. Printed copies are uncontrolled Copyright 2007, Ford Global Technologies, LLC Page 6 of 6
