Cylinder Head Studs, HT Steel, Yamaha®, Various 660's, 2001-2008

Yamaha® Grizzly™ 660 2002-2008
Yamaha® Raptor™ 660 2001-2005
Yamaha® Rhino™ 660 2004-2007

• Nuts are machined from billet high tensile steel and heat treated
• Studs are heat treated 180,000 PSI aircraft alloy steel
• Both nut and stud have rolled threads for the strongest possible threads
• Both nut and stud are black oxide treated for enhanced corrosion resistance
• Standard style studs match the OEM diameters, and have a 12mm thread for the case end, which then reduces to a 10mm diameter for the nut. No modification reqd.
• Oversize studs have a consistent 12mm body diameter and threads on each end for maximum clamping force (cylinder head modification reqd.)

KPMI® Cylinder Studs are made from 180,000 psi yield strength, fine grain, heat treated, aircraft grade alloy steel. When you want a stud that meets proof-stress and maximizes clamping force, look no further. KPMI® “rolls” the threads, heat treats and then centerless grinds the entire body of the stud. Rolling the threads creates the toughest and strongest thread possible and centerless grinding removes notch sensitivity. The final process for all KPMI® Studs is to encase the entire stud with premium corrosion resistant treatment of Black Oxide. Congratulations on your choice to purchase a stud that meets and exceeds your stock-replacement of high-performance needs!
KPMI® nuts are single point machined from high tensile strength Aircraft Alloy Steel. During the machining process close tolerances and smooth surface finishes are maintained. Two critical factors for achieving correct fit and torque. After machining, the nuts are heat treated to a specific depth. This creates hard, wear resistant working surfaces, while retaining a ductile core to prevent cracking under load. The premium black oxide treatment provides excellent corrosion resistance and appearance.