1、 WORLDWIDE FASTENER STANDARD Date: 2000-11-22 WD 900 APPENDIX A General Specifications for Spaced Thread Tapping Screws Printed copies are uncontrolled. Page 1 of 2 Copyright 2000, Ford Global Technologies, Inc. Approximate hole sizes for tapping screws in sheet metals Dimensions in mm MaterialNomin
2、al Hole Diameter Thickness Pierced or Extruded Drilled or Punched Nominal Size over up to and including Steel, Stainless Steel, Drawn Monel etc. Aluminum Alloys Steel, Stainless Steel, Drawn Monel etc. Aluminum Alloys - 0.56 2.2 - 2.2 - 0.56 0.63 2.5 2.2 2.25 - 0.63 0.75 2.5 2.2 2.25 2.2 ST2.9 0.75
3、0.88 2.5 2.2 2.4 2.2 0.88 1.25 - 2.2 2.4 2.2 1.25 1.38 - - 2.4 2.2 1.38 1.75 - - 2.5 2.25 1.75 2.5 - - 2.6 2.4 - 0.56 2.8 - 2.6 - 0.56 0.75 2.8 2.8 2.7 - 0.75 0.80 2.8 2.8 2.7 2.65 1 1.25 - 2.8 2.8 2.65 ST3.5 1.25 1.38 - - 2.8 2.65 1.38 1.75 - - 2.9 2.75 1.75 2.5 - - 3 2.85 2.5 3 - - 3.2 3 3 6 - - -
4、 3 - 0.5 3.5 - - - 0.5 0.63 3.5 3.5 3.2 - 0.63 0.88 3.5 3.5 3.2 2.95 0.88 1.13 3.5 3.5 3.2 3 ST4.2 1.13 1.38 3.5 3.5 3.3 3.2 1.38 2.5 - - 3.5 3.5 2.5 3 - - 3.8 3.7 3 3.5 - - 3.9 3.8 3.5 10 - - - 3.9 - 0.5 4 - - - 0.5 0.75 4 4 3.7 - 0.75 1.13 4 4 3.7 3.7 1.13 1.38 4 4 3.9 3.7 1.38 1.75 - - 3.9 3.7 ST
5、4.8 1.75 2.5 - - 4 3.8 2.5 3 - - 4.1 3.8 3 3.5 - - 4.3 3.9 3.5 4 - - 4.4 3.9 4 4.75 - - 4.4 4 4.75 10 - - - 4.2 - 1.38 5.3 - 4.9 - 1.38 1.75 - - 5 5 1.75 2 - - 5.2 5 ST6.3 2 3 - - 5.3 5.2 3 4 - - 5.8 5.3 4 4.75 - - 5.9 5.4 4.75 5 - - - 5.6 5 10 - - - 5.6 NOTE: Because conditions differ widely, it ma
6、y be necessary to vary the hole size to suit a particular application. The hole sizes tabulated above represent recommendations based on practical experience of screw producers and users as presented in ISO and are for information only. * Hole sizes shown for metal thickness greater than 1.9 are rec
7、ommended for types B only. Hole tolerance +/- 0.05mm WORLDWIDE FASTENER STANDARD Date: 2000-11-22 WD 900 APPENDIX A General Specifications for Spaced Thread Tapping Screws Printed copies are uncontrolled. Page 2 of 2 Copyright 2000, Ford Global Technologies, Inc. Dimensions in mm Nominal Hole Diamet
8、er Nominal Size Phenol - Formaldehyde Cellulose - Acetate Cellulose - Nitrate Polyacrylate, Polystyrene ST2.9 2.55 2.4 ST3.5 3.2 3 ST4.2 3.8 3.7 ST4.8 4.5 4.3 ST6.3 6 5.6 NOTE: Because conditions differ widely, it may be necessary to vary the hole size to suit a particular application. The hole sizes tabulated above represent recommendations based on practical experience of screw producers and users as presented in ISO and are for information only.
