Cobalt Jobbers contain a percentage of Cobalt in their steel, greatly increasing their wear resistance. shank size is the same as the diameter of the drill
'COB' drill bits are made in the USA with M42 8% cobalt steel
'IMPORT' drill bits are made with M35 5% cobalt steel
Sets Also Available
Cobalt Jobbers - Letter Sizes
Cobalt Jobbers contain a percentage of Cobalt in their steel, greatly increasing their wear resistance. shank size is the same as the diameter of the drill
Cobalt Jobbers - Number / Wire Sizes
Cobalt Jobbers contain a percentage of Cobalt in their steel, greatly increasing their wear resistance. shank size is the same as the diameter of the drill
