6 x 5/8 x 1/8 Carbide Jointer / Planer Knives, Delta, Craftsman, Rockwell, others Go to amazon.com Related posts Where to find jointer blades delta? FeatureMade of Tungsten Carbide for the longest lifeset of 3 DescriptionThese carbide tipped knives are very hard at roughly 89 RC and last approximately 10 times longer than high speed steel.