Machine Comparison
Haas ST-25 vs Haas ST-28
Haas Automation vs Haas Automation · CNC Lathes / Turning Centers
Summary
The Haas ST-28 is the big-bore version of the Haas ST-25. The two share the same travels, 8.4 in (213 mm) in X and 22.5 in (572 mm) in Z, the same 13 in (330 mm) maximum turning diameter, a 12-Station BOT turret and 945 ipm (24 m/min) rapids. What the step up buys is a larger spindle.
The Haas ST-28 passes 4 in (102 mm) bar against 3 in (76 mm), carries a 12 in (305 mm) chuck against 10 in (254 mm) on an A2-8 nose against 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. The Haas ST-25 spins slightly faster, 3,400 rpm against 3,200 rpm. Haas lists the ST-25 at US$80,995 and the ST-28 at US$88,995.
Specifications Comparison
| Specification | Haas ST-25 | Haas ST-28 |
|---|---|---|
| X-Axis Travel | 8.4 in (213 mm) | 8.4 in (213 mm) |
| Z-Axis Travel | 22.5 in (572 mm) | 22.5 in (572 mm) |
| Max Turning Diameter | 13 in (330 mm) | 13 in (330 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 |
| Tool Capacity | 12-Station BOT | 12-Station BOT |
| Rapid Traverse | 945 ipm (24 m/min) | 945 ipm (24 m/min) |
| Machine Weight | 9,000 lb (4,083 kg) | 10,240 lb (4,645 kg) |
| Published List Price | US$80,995 | US$88,995 |
Advantages
Haas ST-25
- Lower published list price, US$80,995 against US$88,995
- 3,400 rpm spindle against 3,200 rpm
Haas ST-28
- 4 in (102 mm) bar capacity against 3 in (76 mm)
- 40 hp (29.8 kW) spindle against 30 hp (22.4 kW)
- 425 ft-lbf @ 325 rpm (576 N·m @ 325 rpm) against 300 ft-lbf @ 500 rpm (407 N·m @ 500 rpm)
- 12 in (305 mm) chuck on an A2-8 nose against 10 in (254 mm) on A2-6
Verdict
Buy the Haas ST-28 if any of the work is bar or tube over 3 in (76 mm), or short large-bore parts such as couplings, bushings and flanges: the 4 in (102 mm) bar capacity and 425 ft-lbf of torque are what the higher list price, US$88,995 against US$80,995, pays for. If the bar stays at 3 in (76 mm) or under, the Haas ST-25 does the same work in the same envelope for less.