This Socket Head Cap Screw/Bolt Kit replaces the eight (8) Mercury Flywheel Center Hub Screws / Bolts. They are rated at 170K psi tensile strength, 20K psi stronger than Grade 8. 
 
The ASTM B633 Type II Zinc plating provides a colorful yellow chromate that is corrosion-resistant with a minimum 96-hour salt spray.
 
It's recommended to remove and replace each bolt without dissembling the hub and flexplate. Do this in a star pattern, one at a time, and torque each bolt to 20 ft-lbs with a drop of RED 271 Loctite.
 
This kit includes eight (8) Flywheel Center Hub 170K PSI Screws/Bolts for the Mercury Racing Light-Weight Aluminum and Mercury V6 Stock Steel 19 amp Flywheels.