i/Screw_thread" title="Screw thread">screw thread</a> standards which use the same bolt heads and nut hexagonal sizes, the others being <i><a href="//en.wikipedia.org/wiki/British_Standard_Fine_thread" title="British Standard Fine thread" class="mw-redirect">British Standard Fine thread</a></i> (<b>BSF</b>) and <i><a href="//en.wikipedia.org/wiki/British_Standard_Cycle" title="British Standard Cycle">British Standard Cycle</a></i>. These three are collectively called <b>Whitworth threads</b>.</p>
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