Haas ST-20Y

$80,000 - $110,000 Updated 2026-03-10

Key Specifications

Max Spindle

4,000 RPM

Tool Capacity

12-station BMT-65

Spindle Power

14.9 kW (20 hp)

max swing

533 mm (21 in)

max cutting diameter

298 mm (11.75 in)

max cutting length

572 mm (22.5 in)

Overview

The Haas ST-20Y is a Y-axis CNC turning center built on the redesigned ST-20 platform. Haas re-engineered the castings from scratch, dropping the footprint 11% while adding a 63.5 mm (2.5 in) drawtube bore, 25% larger than the previous generation. That alone makes it a different machine for production bar work.

Max swing is 533 mm (21 in) with a cutting envelope of 298 mm (11.75 in) diameter by 572 mm (22.5 in) length. The A2-6 spindle puts out 14.9 kW (20 hp) and 203 Nm (150 ft-lb) of torque at 500 RPM, topping out at 4,000 RPM. For a mid-size Y-axis lathe at this price, the torque curve is competitive.

The Y-axis gives you +/-50.8 mm (+/-2.0 in) of travel. Paired with a 12-station BMT-65 turret and C-axis live tooling spinning at 6,000 RPM with 3.7 kW (5 hp), the ST-20Y handles cross-drilling, flat milling, hex work, and tapping without moving the part to a VMC. Done-in-one capability at a Haas price point.

Haas runs the NGC control across their entire lineup. Programmers who know the mill side can jump onto the lathe with minimal retraining. The control supports conversational programming, G-code, and canned turning cycles.

At $80,000-$110,000 configured, the ST-20Y undercuts the Mazak QT-250MSY and Okuma LB3000 EX II by $30-50K. You trade some rigidity and spindle power for that savings. For shops that need Y-axis turning without a six-figure commitment, it's the go-to value play in the segment. NYC CNC's purchase of an ST-20Y for their shop floor speaks to its reputation among working machinists. Specs sourced from Haas Automation published data.

Full Specifications

Parameter	Value
Max Swing	533 mm (21 in)
Max Cutting Diameter	298 mm (11.75 in)
Max Cutting Length	572 mm (22.5 in)
Max Spindle Speed	4,000 RPM
Spindle Motor Power	14.9 kW (20 hp)
Spindle Torque	203 Nm (150 ft-lb) @ 500 RPM
Spindle Nose	A2-6
Spindle Bore	88.9 mm (3.5 in)
Chuck Size	210 mm (8.3 in)
Bar Capacity	63.5 mm (2.5 in)
X Axis Travel	213 mm (8.4 in)
Y Axis Travel	±50.8 mm (±2.0 in)
Z Axis Travel	572 mm (22.5 in)
Rapid Traverse X Y	12 m/min (472 in/min)
Rapid Traverse Z	24 m/min (945 in/min)
Tool Capacity	12-station BMT-65
Live Tool Speed	6,000 RPM
Live Tool Power	3.7 kW (5 hp)
C Axis Accuracy	±0.01°
Coolant Capacity	208 L (55 gal)
CNC Control	Haas Next Generation Control (NGC)

Specifications sourced from haascnc.com — verified 2026-03-28

Strengths & Limitations

Strengths

Y-axis and live tooling at $80-110K is $30-50K cheaper than Mazak or Okuma equivalents with similar capability
Redesigned 63.5 mm (2.5 in) drawtube bore is 25% larger than the previous generation, covering most common bar stock sizes
BMT-65 turret provides better rigidity and tool clamping than the older BOT design, improving milling accuracy
Same NGC control as Haas mills, so cross-training operators takes hours instead of weeks
6,000 RPM live tooling at 3.7 kW handles cross-drilling, tapping, and flat milling without a second setup
Strong Haas dealer network with same-day parts availability on wear items and consumables
11% smaller footprint than the previous generation saves floor space in tight shops

Limitations

14.9 kW (20 hp) spindle is outgunned by the Mazak QT-250MSY's 18.5 kW on heavy roughing in tough materials
No sub-spindle option limits done-in-one capability for parts needing back-working operations
Forum reports of Y-axis turret alignment drift every 4-6 months on some units, requiring repeat service visits
C-axis ring gear failures have been reported by multiple owners, with suspected software-related root cause
3.7 kW (5 hp) live tooling lacks the power for aggressive milling, deep pockets, or large face mills

Best For

Job shops adding Y-axis turning capability without a six-figure machine investment Short-run parts with off-center features like cross-holes, flats, hexes, and keyways Production bar work in stock up to 63.5 mm (2.5 in) diameter Haas mill shops expanding into turning who want consistent NGC control programming Automotive, hydraulic, and pneumatic fitting manufacturers running mixed part families Shops doing done-in-one turning and light milling to eliminate second-op VMC time

Frequently Asked Questions

01 What does a Haas ST-20Y cost?

Base price is around $80,000. Common options include live tooling, tailstock, parts catcher, bar feeder, and chip conveyor, pushing configured price to $95,000-$110,000. Used ST-20Y machines from 2018-2023 sell in the $35,000-$65,000 range depending on hours and options.

02 What changed on the redesigned ST-20Y?

Haas re-engineered the castings for an 11% smaller footprint and increased the drawtube bore to 63.5 mm (2.5 in), a 25% jump over the old model. The turret moved to a BMT-65 design for better live tooling rigidity, and the overall casting geometry uses a steeper wedge angle for improved chip evacuation.

03 How does the ST-20Y compare to the Mazak QT-250MSY?

The Mazak has more spindle power (18.5 vs 14.9 kW), larger bar capacity (65 vs 63.5 mm), BMT tooling, and a sub-spindle option. But it costs $40-70K more. The ST-20Y is the value play; the Mazak is the production machine for high-volume or tougher materials.

04 Can the ST-20Y do serious milling work?

It handles cross-drilling, tapping, flat milling, and light pocketing well with 3.7 kW of live tool power at 6,000 RPM. For heavy milling operations like deep pockets or 3D surfacing, you'll want a dedicated mill-turn like the Mazak INTEGREX or Okuma MULTUS.

05 Are there known reliability issues with the ST-20Y?

Forum reports flag two recurring problems: Y-axis turret alignment drift requiring periodic recalibration, and C-axis ring gear failures tied to a suspected servo engagement bug. Both issues have multiple threads on Practical Machinist. Haas service response is generally quick, but repeat visits frustrate owners.