Metric Socket Head Cap Screw Lengths

Length is measured from base of head. Minimum thread length is 2 x diameter + 6 mm. Sizes to small for this formula are fully threaded.
  1. Heat Treated Black Alloy Steel exceeds grade 8 and has a minimum tensile strength of 176,000 psi.
    Excerpt from McMaster Carr.
    Class 12.9 Black Alloy Steel (Metric)- DIN 912.
    Screw
    Length
    Screw Size
    M1.6M2M3M4M5M6M8M10 M12M14M16M20M24M30
    3 x - - - - - - - - - - - - -
    4 x - - - - - - - - - - - - -
    5 x x - - - - - - - - - - - -
    6 x x x x - - - - - - - - - -
    8 - x x x - - - - - - - - - -
    10 - - x x x x x - - - - - - -
    12 - x x x x x - - - - - - - -
    14 - - x x x x - - - - - - - -
    16 - - x x x x x x - - - - - -
    18 - - - x x x x - - - - - - -
    20 - - x x x x x x - - - - - -
    22 - - - - x x x - - - - - - -
    25 - - x x x x x x x - - - - -
    30 - - x x x x x x x x x - - -
    35 - - x x x x x x x x x - - -
    40 - - - x x x x x x x x - - -
    45 - - - - - x x x x - x - - -
    50 - - - - x x x x x x x x - -
    55 - - - - x x x x x - - - - -
    60 - - - - x x x x x x x x x -
    65 - - - - - x x x x x x x x -
    70 - - - - - x x x x - - x x -
    75 - - - - - - x - x - - - - -
    80 - - - - - - x x x x - x x x
    90 - - - - - - x x x x - x x x
    100 - - - - - - x x x x - x x x
    110 - - - - - - x x x x - x x x
    120 - - - - - - x x x x - x x x
    150 - - - - - - x x x x - x x x

  2. Type 18-8 Stainless Steel offers excellent corrosion resistance with a minimum tensile strength of 75,000 psi.
    Excerpt from McMaster Carr.
    Class 12.9 Black Alloy Steel
    (Metric)- DIN 912.
    Screw
    Length
    Screw Size
    M3M4M5M6M8M10 M12
    6 x - - - - - -
    8 x - - - - - -
    10 x x x x - - -
    12 x x x x - - -
    16 - x x x - - -
    20 x x x x x x -
    25 - x x x x x -
    30 - - - x x x x
    35 - - - x x x -
    40 - - - x x - -
    50 - - - x x x x
    55 - - - - x - -