These Lunati Signature Series crankshafts are manufactured from the highest quality 4340 certified steel. The material meets all aircraft-quality standards for material cleanliness and purity standards. They feature drilled rod journals with lightening holes to reduce the inertia weight of the crankshaft and a surface finish that is a Grade 5 RMS or better. Whether you are building an engine for the street or the track, Lunati can provide the Signature Series crankshafts to fit your needs.