Cast Iron Machining Calculator
Calculate optimal CNC machining parameters for cast iron - gray iron, ductile iron (SG), and ADI. Dry machining optimization for production efficiency - tailored for South African manufacturing.
Material Selection
Gray Cast Iron FC200 (Class 20)
General purpose gray iron, good machinability
Fe-C-Si with graphite flakes
190 HB
70%
Type A (random flakes)
Engine blocks, machine bases, pump housings, general castings
Tool & Operation Parameters
Standard for gray iron machining
Cast Iron Machining Guide
DRY machining preferred! Graphite flakes cause abrasion—powdery chips, excellent chip control.
Needs coolant. Continuous chips require chip breakers. More ductile than gray iron.
Very hard! Machine BEFORE austempering. CBN/ceramic tools required after treatment.
Why This Calculator?
- 8 Cast Iron Grades: Gray FC200-FC300, ductile 400-600, ADI, white iron, malleable
- Dry Machining Optimization: Gray iron machines best dry—cost savings, cleaner shop
- Tool Life Prediction: Abrasive cast iron causes rapid wear—accurate tool life estimates
- CBN & Ceramic Tools: Advanced tooling for hard cast iron and high-speed operations
- Health & Safety: Dust extraction warnings for dry machining compliance (OHS Act)
- South African Context: Local foundries, ZAR pricing, SABS standards
South African Context
Engine blocks, pump housings, machine bases, brake drums, mining equipment, gearbox housings, cylinder heads, valve bodies
Gray and ductile iron castings available from SA foundries. ADI heat treatment limited availability—specialized service.
ZAR cost savings: no coolant purchase/disposal, cleaner shop floor, reduced maintenance. Requires proper dust extraction (OHS Act).
Cast Iron Grades Quick Reference
| Grade | Type | Machinability | Hardness (HB) | Dry Machining | Optimal Speed | Applications |
|---|---|---|---|---|---|---|
| Gray Cast Iron FC200 (Class 20) | Type A (random flakes) | 70% | 190 HB | Yes | 130 m/min | Engine blocks, machine bases, pump housings, general castings |
| Gray Cast Iron FC250 (Class 25) | Type A (uniform distribution) | 65% | 210 HB | Yes | 115 m/min | Brake drums, flywheels, cylinder heads, gearbox housings |
| Gray Cast Iron FC300 (Class 30) | Fine flakes (higher strength) | 55% | 240 HB | Yes | 100 m/min | Heavy-duty machine tool structures, diesel engine components |
| Ductile Iron 400-18 (SG Iron) | Spheroidal (nodular) | 65% | 170 HB | No | 115 m/min | Crankshafts, steering knuckles, suspension components, valve bodies |
| Ductile Iron 500-7 (Pearlitic) | Spheroidal with pearlitic matrix | 50% | 230 HB | No | 90 m/min | Gears, high-strength crankshafts, heavy-duty components |
| Ductile Iron 600-3 (Austempered ADI) | Spheroidal with bainitic/ausferritic matrix | 35% | 280 HB | No | 70 m/min | Heavy-duty gears, crankshafts, suspension arms (automotive/mining) |
| White Cast Iron (Chilled) | No graphite - carbides instead | 10% | 450 HB | No | 30 m/min | Mill liners, crusher jaws, wear plates, grinding balls |
| Malleable Iron (Blackheart) | Temper carbon (annealed) | 80% | 120 HB | No | 160 m/min | Pipe fittings, agricultural equipment, small castings |