Measure them. The M8 will measure about 8 mm in diameter, more likely, just a touch under size , (.31496) The M10 , about 10 mm in diameter, (.3937) and the M12 about 12 mm in diameter, (.4724). The M designates the bolt is Metric and the number after the M indicates the size. The number after that is the length. ENGLISH/ METRIC BOLT SUBSTITUTION TABLE. EQUIVALENT METRIC BOLT SUBSTITUTION – ASTM GRADE BOLT SIZES F - 568 CLASS 4.6 F - 568 CLASS 8.8 F - 588 CLASS 8.8.3 F - 568 CLASS 9.8 F - 568 CLASS 10.9 A - 325M TYPE 1 OR 2 A - 325M TYPE METRIC ENGLISH 3 (MM) (INCHES) HOLE DIAM (MM) ENGLISH - ASTM GRADE SPECIFIED. With metric threads tapping drill size is easy to work out because it is the bolt diameter minus the thread pitch so, for example, a standard pitch M16 bolt has a pitch of 2.0mm so the tapping drill size is 16 - …

The size of a metric screw or bolt is specified as diameter, pitch and length, in millimeters (millimeters is abbreviated mm). For nuts, size will appear as diameter and pitch. There is an exception though—if pitch isn't specified, the fastener is coarse threaded. Consider this size…. M8-1.0 x 20. nominal size (d) body diameter head thickness across the flats across corners; d (max) d (min) h (max) h (min) f (max) f (min) c (max) c (min) m10 : 10.00: 9.78 32 rows The bolt chart provides both US and metric size s. NOMINAL DIAMETER (NOMINAL BOLT …

Amazon's Choice for metric bolt sizes . Deluxe Hardware Assortment Kit with ProfessionalNo Mix Case (1,300 Piece, 60 Sizes , Nuts, Bolts , Washers Screws) by Jackson Palmer. 4.6 out of 5 stars 71. $35.99 $ 35. 99. Get it as soon as Tomorrow, Mar 13. FREE Shipping by Amazon. 14 rows Metric Bolt Head/Wrench Size . Print this page . Bolt Diameter (mm) Head/Wrench Size … Dec 17, 1998 ISO metric screw thread. They were one of the first international standards agreed when hereanization for Standardization was set up in 1947. [citation needed] The M designation for metric screws indicates the nominal outer diameter of the screw, in millimeters (e.g., an M6 screw has a nominal outer diameter of 6 millimeters).

Shop our selection of M10 , Screws in the Hardware Department at The Home Depot.