1、 WORLDWIDE FASTENER STANDARD WZ102 Date: 2013 05 23 Printed copies are uncontrolled Copyright 2013, Ford Global Technologies, LLC Page 1 of 3 Fastener Torque/clamp force testing Standard Conditions 1 PURPOSE This Worldwide Standard provides a test method for determining the torque/clamping force per
2、formance of fastener finishes specified in WX100 and used on ISO Metric threaded bolts, screws, studs, and nuts under standard conditions. Note: This standard is not intended for use in developing an installation torque specification or for bolts and nuts with washer assemblies. 2. REFERENCES ISO 16
3、047 Fasteners Torque/clamp force testing ISO 4014 Hexagon head bolts Product grades A and B WA 900 Dimensional Requirements for Hexagon and Flanged Hexagon Bolts and Screws, and Hexagon Screw and Washer Assemblies WA 950 Material Requirements and Mechanical Properties of Bolts, Screws, Studs and Scr
4、ew and Washer Assemblies WX 100 Finish Specifications 3. TEST METHOD Testing must be performed per ISO 16047 Fastener Torque/clamp force testing except where modified in this standard. 4. TEST-BEARING PLATES OR TEST WASHERS Comply with ISO 16047 Clause 7.2 with the following specified parameters: De
5、greased test plates or washer Hardness 50 - 60 HRC Roughness Ra 0.4 maximum Use 600 grit wet or dry paper Clearance hole size per Table 1 Table 1 - Test Plates Dimensions in millimeters Nominal Diameter of Test Bolt Hole Diameter dh Width (w) Minimum Thickness (s) Minimum Maximum Minimum M3 3.58 3.4
6、 7.9 0.45 M4 4.68 4.5 10.2 0.7 M5 5.68 5.5 11.6 0.9 M6 6.82 6.6 16.4 1.4 M8 9.22 9 19.4 1.4 M10 11.27 11 22.4 1.8 M12 13.77 13.5 29 2.3 M14 15.77 15.5 32.1 2.3 M16 17.77 17.5 35.8 2.7 M18 20.33 20 - 2.7 M20 22.33 22 42.3 2.7 M22 24.33 24 - 2.7 M24 26.33 26 55.2 3.7 WORLDWIDE FASTENER STANDARD WZ102
7、Date: 2013 05 23 Printed copies are uncontrolled Copyright 2013, Ford Global Technologies, LLC Page 2 of 3 Figure 1 Test Plates (RE-) PREPARATION OF THE TEST PLATES OR WASHER Using 600 “wet or dry“ paper remove any scratching and/or surface finish pick up. The required surface roughness is achieved
8、by rubbing the washer face across an unused piece of 600 “wet or dry“ paper. A single pass of about 150 to 200mm using firm but not excessive pressure has proved to achieve the required roughness. Surface grinding will be needed occasionally to prevent rounding of the washer face. 5. TEST NUTS FOR T
9、ESTING BOLTS, SCREWS AND STUDS Comply with ISO 16047 Clause 7.3 with the following specified parameters: Surface coating per S437 7. TIGHTENING SPEED Rotational speed shall be 30 3 r/min (revolutions/minute) 8. TESTED PARTS Surrogate bolt A surrogate bolt or screw shall be used for validation of new
10、 coatings and where part geometry does not permit direct testing of the production bolt or screw. The bolt shall be M10x1.5, property class 10.9. The bolt dimensions shall conform to the requirements of ISO 4014. Production bolt or screw Where part geometry does permit testing, a production bolt or
11、screw may be used to demonstrate on-going production control. In case of a dispute, a surrogate bolt or screw shall be used. WORLDWIDE FASTENER STANDARD WZ102 Date: 2013 05 23 Printed copies are uncontrolled Copyright 2013, Ford Global Technologies, LLC Page 3 of 3 9. DETERMINATION OF COEFFICIENT OF
12、 FRICTION, tot The coefficient of friction requirement shall be stated in the material specification or product standard (WX100). Coefficient of total friction, tot, shall be determined per ISO 16047 clause 10.2 Friction determination shall be made at 75% of proof load. Bearing diameter, Db, shall b
13、e determined from part print value for dw min and da max. Do not measure from witness mark on test washer. 10. COEFFICIENT OF FRICTION PERFORMANCE REQUIREMENTS Surrogate bolt - Friction values shall be within specification limits Production bolt or screw - Nominal value shall be within specification limits.
