<P> In addition to coarse and fine threads, there is another division of extra fine, or "superfine" threads, with a very fine pitch thread . Superfine pitch metric threads are occasionally used in automotive components, such as suspension struts, and are commonly used in the aviation manufacturing industry . This is because extra fine threads are more resistant to coming loose from vibrations . </P> <P> Below are some common wrench sizes for metric screw threads . Hex head widths (width across flats, wrench size) are for DIN 934 hex nuts and hex head bolts . Other (usually smaller) sizes may occur for reasons of weight and cost reduction . </P> <Table> <Tr> <Th> </Th> <Th_colspan="5"> Wrench size (mm) </Th> </Tr> <Tr> <Th> Thread </Th> <Th_colspan="2"> Hex nut & bolt </Th> <Th> Socket head cap screw </Th> <Th> Button head cap screw Flat head counter - sunk cap screw </Th> <Th> Set screw </Th> </Tr> <Tr> <Th> </Th> <Th> ISO </Th> <Th> DIN </Th> <Th> </Th> <Th> </Th> <Th> </Th> </Tr> <Tr> <Td> M1 </Td> <Td> - </Td> <Td> 2.5 </Td> <Td> - </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M1. 2 </Td> <Td> - </Td> <Td> </Td> <Td> - </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M1. 4 </Td> <Td> - </Td> <Td> </Td> <Td> 1.25 </Td> <Td> - </Td> <Td> 0.7 </Td> </Tr> <Tr> <Td> M1. 6 </Td> <Td> 3.2 </Td> <Td> 3.2 </Td> <Td> 1.5 </Td> <Td> - </Td> <Td> 0.7 </Td> </Tr> <Tr> <Td> M2 </Td> <Td> </Td> <Td> </Td> <Td> 1.5 </Td> <Td> 1.25 </Td> <Td> 0.9 </Td> </Tr> <Tr> <Td> M2. 5 </Td> <Td> 5 </Td> <Td> 5 </Td> <Td> </Td> <Td> 1.5 </Td> <Td> 1.3 </Td> </Tr> <Tr> <Td> M3 </Td> <Td> 5.5 </Td> <Td> 5.5 </Td> <Td> 2.5 </Td> <Td> </Td> <Td> 1.5 </Td> </Tr> <Tr> <Td> M3. 5 </Td> <Td> 6 </Td> <Td> 6 </Td> <Td> - </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M4 </Td> <Td> 7 </Td> <Td> 7 </Td> <Td> </Td> <Td> 2.5 </Td> <Td> </Td> </Tr> <Tr> <Td> M5 </Td> <Td> 8 </Td> <Td> 8 </Td> <Td> </Td> <Td> </Td> <Td> 2.5 </Td> </Tr> <Tr> <Td> M6 </Td> <Td> 10 </Td> <Td> 10 </Td> <Td> 5 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> M7 </Td> <Td> 11 </Td> <Td> 11 </Td> <Td> - </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M8 </Td> <Td> 13 </Td> <Td> 13 </Td> <Td> 6 </Td> <Td> 5 </Td> <Td> </Td> </Tr> <Tr> <Td> M10 </Td> <Td> 16 </Td> <Td> 17 </Td> <Td> 8 </Td> <Td> 6 </Td> <Td> 5 </Td> </Tr> <Tr> <Td> M12 </Td> <Td> 18 </Td> <Td> 19 </Td> <Td> 10 </Td> <Td> 8 </Td> <Td> 6 </Td> </Tr> <Tr> <Td> M14 </Td> <Td> 21 </Td> <Td> 22 </Td> <Td> 10 </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M16 </Td> <Td> 24 </Td> <Td> 24 </Td> <Td> 14 </Td> <Td> 10 </Td> <Td> 8 </Td> </Tr> <Tr> <Td> M18 </Td> <Td> 27 </Td> <Td> 27 </Td> <Td> 14 </Td> <Td> 12 </Td> <Td> - </Td> </Tr> <Tr> <Td> M20 </Td> <Td> 30 </Td> <Td> 30 </Td> <Td> 17 </Td> <Td> 12 </Td> <Td> 10 </Td> </Tr> <Tr> <Td> M22 </Td> <Td> 34 </Td> <Td> 32 </Td> <Td> 17 </Td> <Td> 14 </Td> <Td> - </Td> </Tr> <Tr> <Td> M24 </Td> <Td> 36 </Td> <Td> 36 </Td> <Td> 19 </Td> <Td> 14 </Td> <Td> 12 </Td> </Tr> <Tr> <Td> M27 </Td> <Td> 41 </Td> <Td> 41 </Td> <Td> 19 </Td> <Td> 17 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> M30 </Td> <Td> 46 </Td> <Td> 46 </Td> <Td> 22 </Td> <Td> 17 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> M33 </Td> <Td> 50 </Td> <Td> 50 </Td> <Td> 24 </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M36 </Td> <Td> 55 </Td> <Td> 55 </Td> <Td> 27 </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M39 </Td> <Td> 60 </Td> <Td> 60 </Td> <Td> - </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M42 </Td> <Td> 65 </Td> <Td> 65 </Td> <Td> 32 </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M45 </Td> <Td> 70 </Td> <Td> 70 </Td> <Td> - </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M48 </Td> <Td> 75 </Td> <Td> 75 </Td> <Td> 36 </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M52 </Td> <Td> 80 </Td> <Td> 80 </Td> <Td> 36 </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M56 </Td> <Td> 85 </Td> <Td> 85 </Td> <Td> 41 </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M60 </Td> <Td> 90 </Td> <Td> 90 </Td> <Td> - </Td> <Td> - </Td> <Td> - </Td> </Tr> <Tr> <Td> M64 </Td> <Td> 95 </Td> <Td> 95 </Td> <Td> 46 </Td> <Td> - </Td> <Td> - </Td> </Tr> </Table> <Tr> <Th> </Th> <Th_colspan="5"> Wrench size (mm) </Th> </Tr>

What is the diameter of an m16 bolt
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