Titanium Large Flange Hex Head M6 - 1.00 X 20MM. Grip Length = 3MM. Thread Length = 17MM. The drive for this bolt is an 8MM hex. The flange outer diameter is 15.5MM and has been drilled with 9 consecutive holes for cosmetic appeal. The threads have been rolled for better fatigue resistance. Made from Aircraft grade material that has a Minimum UTS of 140Ksi (925Mpa).