Material Machining Views: 12

Cast iron machining notes and tool selection: Characteristics: 1) Brittle - chips are powdery, not ribbon: chip removal is easy; 2) Hard skin - castings have scale and mold-sand residue: hard, wears tools; 3) Graphite - self-lubricating: low cutting force, good finish; 4) Light work hardening - wear is mainly abrasive (hard particles). Which tool: 1) Standard HSS - usable, cheap, average life: small quantities, low demands; 2) Cobalt HSS (HSS-E) - 30%-50% longer life than standard HSS: batches; 3) Carbide - most wear-resistant, long life: high volume; but brittle - scale can chip it; 4) Coating - TiN or TiAlN: 30%-50% longer life, but graphite weakens coating benefits vs steel; 5) PCD - NOT for cast iron (graphite wears diamond). Parameters: 1) speed - medium: cobalt HSS 600-1200rpm, carbide 1000-2000rpm; 2) feed - medium, 0.08-0.15mm/rev; 3) fluid - cast iron can usually be dry-cut (graphite lubricates), but dust is generated: use compressed air or light fluid; 4) dust - wear a mask, use dust extraction. Notes: 1) remove the hard skin first - scale and mold sand wear tools fast; remove it before chamfering, or use carbide directly (standard HSS wears too fast); 2) sharp edges - dull tools roughen the surface; 3) avoid impact - brittle: feed steadily, no impact; 4) prevent edge chipping - cut from solid toward the edge, not from edge to solid; 5) defects - castings have pores and sand holes; avoid them when chamfering; 6) safety - powdery chips fly: glasses; dust: mask. Cast iron is a relatively easy material - cobalt HSS or carbide with moderate parameters gives quality chamfers. Ask our technical team.