THIS GUIDE IS OFFERED AS AN AID TO MY CUTTING TOOL BUYERS IN CHOOSING WHICH MATERIAL IS BEST SUITED FOR THEIR MACHINING OPERATIONS.

PART THREE

CARBIDES

MOST OF THE CARBIDE GRADES ARE LISTED UNDER AN INDUSTRY CODE OF C-1, C-2, ETC..

THE C-1 THROUGH C-4 GRADES ARE GENERALLY STRAIGHT TUNGSTEN CARBIDE BONDED WITH COBALT. THEY ARE IN GENERAL USED FOR MACHINING CAST IRONS, NONFERROUS METALS INCLUDING TITANIUM, HIGH TEMPERATURE ALLOYS, WORK HARDENED STAINLESS STEELS, AND ABRASIVE NONMETALLIC MATERIALS.

TOUGHNESS DECREASES AND SURFACE SPEED CAPABILITY INCREASES PROCEEDING FROM C-1 TO C-4. THE C-2 GRADE PROVIDE A GOOD COMPROMISE IN PROPERTIES AND MAY BE CATEGORIZED AS "GENERAL PURPOSE". 

THE C-5 THROUGH C-8 GRADES INCLUDE THOSE WHICH CONTAIN VARIOUS COMBINATIONS OF TUNGSTEN CARBIDE, TANTALUM CARBIDE, AND TITANIUM CARBIDE BONDED WITH COBALT. THE C-8 CATEGORY ALSO INCLUDES TOOLS OF STRAIGHT TITANIUM CARBIDE BONDED WITH MOLYBDENUM AND NICKEL.

GRADES C-5 THROUGH C-8 ARE RECOMMENDED FOR MACHINING STEELS.

TOUGHNESS DECREASES AND THE SURFACE SPEED CAPABILITY INCREASES IN GOING FROM C-5 TO C-8.  C-6 IS FOR GENERAL USE.