Machine Comparison
Haas ST-25Y vs Haas ST-28Y
Haas Automation vs Haas Automation · Mill-Turn Machines
Summary
The Haas ST-25Y and Haas ST-28Y are Y-axis turning centers on the same envelope: ± 2 in (± 51 mm) of Y, 22.5 in (572 mm) of Z travel and turning length, an 11.75 in (298 mm) swing, a 6,000 rpm sub-spindle, 4,000 rpm live tools, 12 Stations and 472 ipm (12 m/min) rapids. The ST-28Y is the big-bore, higher-torque version.
The ST-28Y takes 4 in (102 mm) bar against 3 in (76 mm), carries a 12 in (305 mm) chuck on an A2-8 nose against 10 in (254 mm) on A2-6, and delivers 40 hp (29.8 kW) and 425 ft-lbf @ 325 rpm against 30 hp (22.4 kW) and 300 ft-lbf @ 500 rpm. It has 9.4 in (239 mm) of X travel against 8.4 in (213 mm). The ST-25Y spins to 3,400 rpm against 3,200 rpm. Haas lists them at US$127,995 and US$134,995.
Specifications Comparison
| Specification | Haas ST-25Y | Haas ST-28Y |
|---|---|---|
| X-Axis Travel | 8.4 in (213 mm) | 9.4 in (239 mm) ▲ |
| Y-Axis Travel | ± 2 in (± 51 mm) | ± 2 in (± 51 mm) |
| Z-Axis Travel | 22.5 in (572 mm) | 22.5 in (572 mm) |
| Max Turning Diameter | 11.75 in (298 mm) | 11.75 in (298 mm) |
| Max Turning Length | 22.5 in (572 mm) | 22.5 in (572 mm) |
| Bar Capacity | 3 in (76 mm) | 4 in (102 mm) ▲ |
| Chuck Size | 10 in (254 mm) | 12 in (305 mm) |
| Max Spindle Speed | 3,400 rpm ▲ | 3,200 rpm |
| Spindle Power | 30 hp (22.4 kW) | 40 hp (29.8 kW) ▲ |
| Spindle Torque | 300 ft-lbf @ 500 rpm (407 N·m @ 500 rpm) | 425 ft-lbf @ 325 rpm (576 N·m @ 325 rpm) ▲ |
| Spindle Taper / Nose | A2-6 | A2-8 |
| Sub-Spindle Speed | 6,000 rpm | 6,000 rpm |
| 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) |
| Machine Weight | 12,300 lb (5,580 kg) | 10,860 lb (4,926 kg) |
| Published List Price | US$127,995 | US$134,995 |
Advantages
Haas ST-25Y
- 3,400 rpm spindle against 3,200 rpm
- Lower published list price, US$127,995 against US$134,995
Haas ST-28Y
- 4 in (102 mm) bar capacity against 3 in (76 mm)
- 425 ft-lbf (576 N·m) of torque against 300 ft-lbf (407 N·m)
- 40 hp (29.8 kW) spindle against 30 hp (22.4 kW)
- 12 in (305 mm) chuck and 9.4 in (239 mm) of X travel
Verdict
Buy on bar size and torque. The ST-28Y suits oil and gas fittings, flanges and couplings run from pipe or heavy bar up to 4 in (102 mm), where 425 ft-lbf at 325 rpm matters. The ST-25Y suits bar and chuck work up to 3 in (76 mm) with milled flats and cross-holes, where the slightly higher 3,400 rpm spindle and lower US$127,995 list price fit.