DIN 604 - Flat Countersunk Nib Bolts With Hexagon Nut - Steel Standard Dimensions and Specifications Click the Button to Download DIN 604 – Flat Countersunk Nib Bolts With Hexagon Nut – Steel Standard Dimensions and Specifications in PDF Format DIN 604 PDF Steel: 4.8, 5.8, 8.8, 10.9, 12.9Stainless: A2,A4 Terminology and Measurements d – The Nominal Diameter of the Threadl – Length of Bolts – Size Hex Head Turnkeyb – Length of the Threadk – Head Heighte – The Diameter of the Circumscribed Circle