PICTURES ARE REPRESENTATIVE OF ITEM, BUT ARE NOT OF THE ACTUAL ITEM. Product dimensions, finish, head markings, thread length, stamping shape or forging shape, etc., may differ from picture. Products are guaranteed to meet the specifications to which they are manufactured. Specifications allow for tolerances in dimension and shape, which can vary from lot to lot. Machine screws form a fastening superior in strength to spaced thread screws. Metric screws are the type almost exclusively used in items manufactured in Europe. Steel: Class 4.8 machine screws shall be made from a carbon steel, partially or fully annealed as required, which conforms to the following chemical composition Carbon: 0.55% maximum; Phosphorus: 0.05% maximum; Sulfur: 0.06% maximum. Rockwell B 71 - 99.5. Stainless: A2 - A4 Stainless. Machine Pack Count - Margin error of +/- 5%