British Standard

BS 3692 Hexagon Head Bolts   Dimensions of Hexagon Head

BS 4168 Socket Head Cap Screws   Dimensions of Socket H

BS 4395   Dimensions of Metric Flat Round Washers for Hig

BS 4183 Metric Slotted Countersunk Head Machine Screws  

BS 4463 Metric Sized Crinkle Washers   Dimensions of Me