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Head Clearances Around Screw Heads ...

Bolts Holes, Min Spacings, And Spanner Clearances Precision Hexagon Bolts And Screws

Dimensions in mm

Size Hole D Min P Clearance G Nom. Size
Spanner		 M N H
a b c
M3 3.5 12 10 8 10 - 5.5 8 8 -
M4 4.5 15 10 8 12 14 7 10 10 19
M5 5.5 20 10 8 12 14 8 10 10 19
M6 6.5 25 14 8 16 17 10 10 12 25
M8 9.0 30 18 12 20 22 13 12 15 25
M10 11.0 40 28 16 25 27 17 16 18 32
M12 13.5 50 30 16 30 30 19 18 20 32
M16 17.5 50 30 22 35 38 24 25 28 50
M20 22.5 60 32 25 40 46 30 30 35 50
M24 26.5 75 48 28 45 55 36 35 45 -
M30 33.0 100 60 40 60 71 46 45 55 -
M36 39.5 100 60 45 70 83 55 55 65 -




High Strength Friction Grip Bolts

Dimensions in mm

Size Min P Clearance G Nom. Size
Spanner		 M N
a b c
M16 60 30 25 38 27 42 30 35
M20 70 48 28 42 48 32 30 35
M24 80 48 40 55 65 41 45 50
M30 100 60 45 65 77 50 55 60
M36 120 60 45 70 81 60 70 75

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Last Updated 13/03/2008