Haas ST-40
Key Specifications
Max Spindle
Tool Capacity
Spindle Power
max part swing
max cutting diameter
max cutting length
Overview
The Haas ST-40 is the entry point to the Haas large-frame turning center family. With a 902 mm (35.5 in) max part swing, 762 mm (30 in) max cutting diameter, 1118 mm (44 in) max cutting length, and a 102 mm (4.0 in) bar capacity through an A2-8 spindle, the ST-40 handles the big turning work that mid-size lathes like the ST-20 and ST-30 cannot touch. The redesigned platform delivers more capacity in a smaller footprint than the previous generation, with increased X-axis travel to 508 mm (20 in) and an available BMT75 turret with live tooling.
The 29.8 kW (40 hp) spindle drives through a 2-speed gearbox, producing 1,898 Nm (1,400 ft-lb) of torque at 150 RPM with a max speed of 2,400 RPM. An optional XP high-performance spindle bumps output to 41.0 kW (55 hp) and 2,847 Nm (2,100 ft-lb) of torque for aggressive roughing in tough materials. The 117.3 mm (4.62 in) spindle bore handles bar stock up to 102 mm (4.0 in), covering the most common large-bar production sizes.
At a starting price of approximately $175,995, the ST-40 significantly undercuts comparable large-frame lathes from Doosan, Okuma, and Mazak. The 12-station BOT turret accepts any combination of OD and ID tools, with an optional BMT75 turret for live tooling and C-axis work. The Haas NGC control, extensive HFO dealer network, and straightforward programming make the ST-40 accessible to shops stepping up to large-frame turning for the first time. Specs sourced from Haas Automation published data.
Full Specifications
| Parameter | Value |
|---|---|
| Max Part Swing | 902 mm (35.5 in) |
| Max Cutting Diameter | 762 mm (30 in) with BOT turret; 699 mm (27.5 in) with BMT75 turret |
| Max Cutting Length | 1,118 mm (44 in) |
| Chuck Size | 381 mm (15 in) |
| Bar Capacity | 102 mm (4.0 in) |
| Spindle Nose | A2-8 |
| Spindle Bore | 117.3 mm (4.62 in) |
| Max Spindle Speed | 2,400 RPM |
| Spindle Motor Power | 29.8 kW (40 hp) |
| Spindle Torque | 1,898 Nm (1,400 ft-lb) @ 150 RPM |
| Spindle Drive | 2-Speed Gearbox |
| Xp Spindle Power | 41.0 kW (55 hp) |
| Xp Spindle Torque | 2,847 Nm (2,100 ft-lb) @ 150 RPM |
| X Axis Travel | 508 mm (20 in) |
| Z Axis Travel | 1,118 mm (44 in) |
| Rapid Traverse X | 18.0 m/min (710 ipm) |
| Rapid Traverse Z | 18.0 m/min (710 ipm) |
| Max Thrust X | 24,465 N (5,500 lbf) |
| Max Thrust Z | 40,034 N (9,000 lbf) |
| Tool Capacity | 12-station BOT |
| Tailstock Taper | MT5 |
| Tailstock Travel | 1,067 mm (42 in) |
| Coolant Capacity | 360 L (95 gal) |
| Machine Weight | 9,861 kg (21,740 lb) export crate |
| CNC Control | Haas Next Generation Control (NGC) |
Specifications sourced from haascnc.com — verified 2026-03-28
Strengths & Limitations
Strengths
- Redesigned large-frame platform with increased X-axis travel to 508 mm (20 in) and larger 902 mm (35.5 in) max part swing in a smaller overall footprint
- 40 hp spindle with 1,400 ft-lb of torque through a 2-speed gearbox handles aggressive roughing in steel, stainless, and cast iron without hesitation
- Optional XP spindle upgrade to 55 hp and 2,100 ft-lb of torque for shops pushing heavy material removal in tough alloys
- Available BMT75 turret with live tooling and C-axis eliminates second-op milling on parts with cross-holes, flats, and keyways
- At ~$176K starting, significantly undercuts comparable large-frame lathes from Doosan Puma 4100, Okuma LB4000 EX, and Mazak QT-350
Limitations
- 2,400 RPM max spindle speed limits surface speed on smaller-diameter aluminum finishing compared to direct-drive competitors running 3,500+ RPM
- 4.0-inch bar capacity may be limiting for shops needing larger through-bore work — the ST-45 with its 7.0-inch bore is the next step up
- 15-inch chuck is standard; 18-inch chuck requires stepping up to the ST-45 platform
- Machine weight approaching 10,000 kg requires substantial floor preparation and rigging for installation
Best For
Frequently Asked Questions
01
The Haas ST-40 starts at approximately $175,995 for the base configuration. Adding tailstock, chip conveyor, high-pressure coolant, parts catcher, BMT75 live tooling turret, and the XP high-performance spindle can push the configured price to $220,000-$250,000. Used ST-40 machines from 2018-2023 typically sell in the $90,000-$150,000 range depending on hours and options.
02
The ST-45 shares the same castings and footprint as the ST-40 but features a 178 mm (7.0 in) spindle bore compared to the ST-40 117.3 mm (4.62 in) bore, an A2-11 spindle nose instead of A2-8, an 18-inch chuck option, and a lower max spindle speed of 1,400 RPM. The ST-45 is purpose-built for large-bore tubular work, while the ST-40 is optimized for general large-frame turning with higher RPM capability.
03
Yes, with the optional BMT75 turret and C-axis. The BMT75 turret supports 4,000 RPM live tooling with either 12 or 24 stations, enabling cross-drilling, milling flats, hexes, and keyways without a second setup on a VMC. The base BOT turret does not support live tooling.
04
The Doosan Puma 4100 offers stiffer box-way construction, a Fanuc control with broader CAM compatibility, and BMT tooling as standard. The Haas ST-40 costs $30-50K less, provides the NGC control familiar to Haas shops, and has a stronger North American dealer network. For pure rigidity and precision on heavy cuts, the Doosan has an edge. For value and ecosystem consistency, the Haas wins.
Videos
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Community Discussions
Community discussion — Is Haas Really That Bad? : r/Machinists - Reddit
Community discussion — New Haas Tooling : r/Machinists - Reddit
Community discussion — Has anyone tried Haas mill tooling? : r/Machinists - Reddit
Owner experience and review — Milling CNC precision & stability - why does Haas suck? : r ...
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