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 serve different jobs. Both are Y-axis lathes with a 40 hp (29.8 kW) A2-8 spindle, 4 in (102 mm) bar capacity and 4,000 rpm live tools, but the ST-40Y is a much larger machine, with 20 in (508 mm) of X travel against 9.4 in (239 mm) and a 27.5 in (699 mm) swing against 13.75 in (349 mm).
The ST-40Y turns 44 in (1,118 mm) long against 32.5 in (826 mm), has ± 3 in (± 76 mm) of Y travel against ± 2 in (± 51 mm), carries a 15 in (381 mm) chuck against 12 in (305 mm) and delivers 1,400 ft-lbf @ 150 rpm against 425 ft-lbf @ 325 rpm. The ST-35Y spins faster, 3,200 rpm against 2,400 rpm. Haas lists the ST-35Y at US$151,995 and the ST-40Y at US$241,995.
Specifications Comparison
| Specification | Haas ST-35Y | Haas ST-40Y |
|---|---|---|
| X-Axis Travel | 9.4 in (239 mm) | 20 in (508 mm) ▲ |
| Y-Axis Travel | ± 2 in (± 51 mm) | ± 3 in (± 76 mm) ▲ |
| Z-Axis Travel | 32.5 in (826 mm) | 44 in (1,118 mm) ▲ |
| Max Turning Diameter | 13.75 in (349 mm) | 27.5 in (699 mm) ▲ |
| Max Turning Length | 32.5 in (826 mm) | 44 in (1,118 mm) ▲ |
| Bar Capacity | 4 in (102 mm) | 4 in (102 mm) |
| Chuck Size | 12 in (305 mm) | 15 in (381 mm) |
| Max Spindle Speed | 3,200 rpm ▲ | 2,400 rpm |
| Spindle Power | 40 hp (29.8 kW) | 40 hp (29.8 kW) |
| Spindle Torque | 425 ft-lbf @ 325 rpm (576 N·m @ 325 rpm) | 1,400 ft-lbf @ 150 rpm (1,898 N·m @ 150 rpm) ▲ |
| Spindle Taper / Nose | A2-8 | A2-8 |
| Live Tool Speed | 4,000 rpm | 4,000 rpm |
| Tool Capacity | 12 | 12 |
| Rapid Traverse | 472 ipm (12 m/min) | 472 ipm (12 m/min) |
| Published List Price | US$151,995 | US$241,995 |
Advantages
Haas ST-35Y
- 3,200 rpm spindle against 2,400 rpm
- Lower published list price, US$151,995 against US$241,995
- 12-station BMT-65 turret
Haas ST-40Y
- 27.5 in (699 mm) max turning diameter against 13.75 in (349 mm)
- 1,400 ft-lbf (1,898 N·m) of torque against 425 ft-lbf (576 N·m)
- 44 in (1,118 mm) turning length against 32.5 in (826 mm)
- ± 3 in (± 76 mm) of Y travel against ± 2 in (± 51 mm)
Verdict
Pick by diameter. The ST-35Y is for long shafts and tubular parts within a 13.75 in (349 mm) swing, where 3,200 rpm and a US$151,995 list price fit. The ST-40Y is for large forgings, castings, flanges and housings up to 27.5 in (699 mm) in diameter in tough material, where 1,400 ft-lbf of low-speed torque and 44 in (1,118 mm) of turning length are needed.