20 piece ACER Racing Titanium Lug Bolt set for Air Cooled Porsches 1974-1989 and also the Porsche 930 and Porsche 964. M14x1.5 - 19mm hex head - 32mm overall height, R14 radius ball base. Manufactured from aerospace grade 6AL4V Titanium, these titanium lug bolts will not corrode or rust and offer a significant weight savings over steel lug bolts while giving a very sporty and aggressive look. Titanium is 50% lighter than steel, yet considerably stronger. Titanium is also resistant to the constant heating and cooling cycles that destroy steel. Rolled threads for superior fatigue resistance.