Machine Comparison
Haas ST-15 vs Haas ST-20
Haas Automation vs Haas Automation · CNC Lathes
Summary
The Haas ST-15 and Haas ST-20 share the same spindle: 4,000 rpm, 20 hp (14.9 kW), 150 ft-lbf @ 500 rpm on an A2-6 nose, with 2.5 in (64 mm) bar capacity, an 8.3 in (210 mm) chuck and a 12-station BOT turret. The difference is length.
The ST-20 has 22.5 in (572 mm) of Z travel and turning length against 16 in (406 mm), swings 13 in (330 mm) against 12 in (305 mm), and has 8.4 in (213 mm) of X travel against 7.88 in (200 mm). The ST-15 rapids faster at 1,200 ipm (30.5 m/min) against 945 ipm (24 m/min) and weighs 7,900 lb (3,584 kg) against 8,820 lb (4,000 kg). Haas lists the ST-15 at US$70,995 and the ST-20 at US$77,995.
Specifications Comparison
| Specification | Haas ST-15 | Haas ST-20 |
|---|---|---|
| X-Axis Travel | 7.88 in (200 mm) | 8.4 in (213 mm) ▲ |
| Z-Axis Travel | 16 in (406 mm) | 22.5 in (572 mm) ▲ |
| Max Turning Diameter | 12 in (305 mm) | 13 in (330 mm) ▲ |
| Max Turning Length | 16 in (406 mm) | 22.5 in (572 mm) ▲ |
| Bar Capacity | 2.5 in (64 mm) | 2.5 in (64 mm) |
| Chuck Size | 8.3 in (210 mm) | 8.3 in (210 mm) |
| Max Spindle Speed | 4,000 rpm | 4,000 rpm |
| Spindle Power | 20 hp (14.9 kW) | 20 hp (14.9 kW) |
| Spindle Torque | 150 ft-lbf @ 500 rpm (203 N·m @ 500 rpm) | 150 ft-lbf @ 500 rpm (203 N·m @ 500 rpm) |
| Spindle Taper / Nose | A2-6 | A2-6 |
| Sub-Spindle Speed | 6,000 rpm | 6,000 rpm |
| Tool Capacity | 12-Station BOT | 12 |
| Rapid Traverse | 1,200 ipm (30.5 m/min) ▲ | 945 ipm (24 m/min) |
| Machine Weight | 7,900 lb (3,584 kg) | 8,820 lb (4,000 kg) |
| Published List Price | US$70,995 | US$77,995 |
Advantages
Haas ST-15
- 1,200 ipm (30.5 m/min) rapids against 945 ipm (24 m/min)
- Lower published list price, US$70,995 against US$77,995
- Lighter at 7,900 lb (3,584 kg) against 8,820 lb (4,000 kg)
Haas ST-20
- 22.5 in (572 mm) turning length against 16 in (406 mm)
- 13 in (330 mm) max turning diameter against 12 in (305 mm)
- 8.4 in (213 mm) of X travel against 7.88 in (200 mm)
Verdict
Same spindle and bar capacity, so buy on part length. The ST-15 suits short bar-fed fittings, couplings and connectors in 2.5 in (64 mm) stock, where its faster rapids and US$70,995 list price help. The ST-20 suits mixed part families with shafts and longer parts that need 22.5 in (572 mm) of turning length and a 13 in (330 mm) swing.