Machine Comparison
Haas ST-35Y vs Haas ST-40Y
Haas Automation vs Haas Automation · Mill-Turn Machines
Summary
The Haas ST-35Y and Haas ST-40Y are both from Haas Automation's mill-turn machines lineup, making this a common upgrade or lineup decision for shops already invested in the Haas Automation ecosystem. The Haas ST-35Y leads in max spindle speed (3,200 RPM vs 2,400 RPM). The Haas ST-40Y leads in chuck size (381 mm (15 in) vs 305 mm (12 in)). These machines are closely matched across most specifications, making the decision more about specific feature priorities, dealer support, and your existing shop ecosystem than raw spec advantages. Both machines are proven performers in production environments and represent solid investments for shops in the market for a mill-turn machine.
Specifications Comparison
| Specification | Haas ST-35Y | Haas ST-40Y |
|---|---|---|
| Max Spindle Speed | 3,200 RPM ▲ | 2,400 RPM |
| Spindle Power | 29.8 kW (40 hp) | 29.8 kW (40 hp) |
| Spindle Torque | 542 Nm (400 ft-lb) @ 500 RPM | 542 Nm (400 ft-lb) @ 500 RPM |
| Tool Capacity | 12-station BMT-65 turret | 12-station BMT-75 turret |
| Chuck Size | 305 mm (12 in) | 381 mm (15 in) ▲ |
| Bar Capacity | 102 mm (4.0 in) | 102 mm (4.0 in) |
| Machine Weight | 8,165 kg (18,000 lb) ▲ | 9,525 kg (21,000 lb) |
| Control | Haas Next Generation Control (NGC) | Haas Next Generation Control (NGC) |
| Max Cutting Diameter | 406 mm (16 in) | 457 mm (18 in) ▲ |
| Max Cutting Length | 1,016 mm (40 in) ▲ | 711 mm (28 in) |
| Max Swing Over Front Apron | 838 mm (33 in) | 914 mm (36 in) ▲ |
| Max Swing Over Cross Slide | 559 mm (22 in) | 660 mm (26 in) ▲ |
| Spindle Torque Optional Gearbox | 1,898 Nm (1,400 ft-lb) @ 150 RPM | 1,898 Nm (1,400 ft-lb) @ 150 RPM |
| Spindle Nose | A2-8 | A2-8 |
| Price Range | $125,000 - $155,000 ▲ | $190,000 - $245,000 |
Advantages
Haas ST-35Y
- Higher maximum spindle speed of 3,200 RPM enables faster cutting on aluminum and non-ferrous materials
- Lighter at 8,165 kg (18,000 lb), potentially easier installation and lower foundation requirements
- Superior max cutting length at 1,016 mm (40 in) vs 711 mm (28 in)
- More competitive pricing at $125,000 - $155,000 compared to $190,000 - $245,000
Haas ST-40Y
- Superior chuck size at 381 mm (15 in) vs 305 mm (12 in)
- Superior max cutting diameter at 457 mm (18 in) vs 406 mm (16 in)
- Superior max swing over front apron at 914 mm (36 in) vs 838 mm (33 in)
- Superior max swing over cross slide at 660 mm (26 in) vs 559 mm (22 in)
Verdict
This is a close matchup. The Haas ST-35Y and Haas ST-40Y trade advantages across different specifications, making neither a clear winner on paper alone. Your decision should come down to practical factors: which dealer is closer, which control system your operators already know, what tooling ecosystem you're invested in, and which machine's specific strengths match your highest-volume work. Get quotes on both, run test cuts with your actual parts if possible, and factor in long-term service and support costs.