Head Bolt Reuseability

Outer Diameter of Cylinder Head Bolts
Cylinder head bolts are tightened by plastic zone tightening method. Whenever the size difference between d1 and d2 exceeds the limit, replace them with new one.

Limit (d1 - d2):................................0.11 mm (0.0043 inch)

If reduction of outer diameter appears in a position other than d2, use it as d2 point.