Haas ST-55

$355,995 - $430,000 Updated 2026-03-12

Key Specifications

Max Spindle

1,000 RPM

Tool Capacity

12-station BOT

Spindle Power

41.0 kW (55 hp)

swing over front apron

876 mm (34.5 in)

swing over cross slide

648 mm (25.5 in)

max cutting diameter

648 mm (25.5 in)

Overview

The Haas ST-55 is the largest turning center in the Haas lineup, purpose-built for heavy, large-bore work that exceeds the capacity of the ST-40 and ST-45 platforms. With a massive 318 mm (12.5 in) spindle bore, an A1-20 spindle nose (front and rear), and a cutting envelope of 648 mm (25.5 in) diameter by 2,032 mm (80 in) length, the ST-55 handles the biggest turning jobs in the Haas catalog — long shafts, large-bore tubular components, and heavy workpieces up to 14,062 kg (31,000 lb) machine weight class.

The 41.0 kW (55 hp) spindle drives through a 2-speed gearbox, producing a staggering 5,762 Nm (4,250 ft-lb) of torque at just 30 RPM. Max spindle speed is 1,000 RPM, reflecting the machine's focus on heavy material removal at low speed rather than high-RPM finishing. The swing over the front apron is 876 mm (34.5 in), with 648 mm (25.5 in) over the cross slide and tailstock. Axis travels are 432 mm (17 in) in X and 2,032 mm (80 in) in Z.

Starting at approximately $355,995, the ST-55 is the flagship of the Haas turning center line. The 12-station BOT turret is standard. The MT6 tailstock with 1,930 mm (76 in) of travel and 20,017 N (4,500 lbf) of thrust supports long, heavy workpieces. For oil and gas, power generation, mining, shipbuilding, and heavy equipment manufacturers that need massive turning capacity with Haas simplicity and pricing, the ST-55 delivers capability that would cost significantly more from European and Japanese builders. Specs sourced from Haas Automation published data.

Full Specifications

Parameter	Value
Swing Over Front Apron	876 mm (34.5 in)
Swing Over Cross Slide	648 mm (25.5 in)
Max Cutting Diameter	648 mm (25.5 in)
Max Cutting Length	2,032 mm (80 in)
Bar Capacity	318 mm (12.5 in)
Spindle Nose	A1-20 Front & Rear
Spindle Bore	318 mm (12.5 in)
Max Spindle Speed	1,000 RPM
Spindle Motor Power	41.0 kW (55 hp)
Spindle Torque	5,762 Nm (4,250 ft-lb) @ 30 RPM
Spindle Drive	2-Speed Gearbox
X Axis Travel	432 mm (17 in)
Z Axis Travel	2,032 mm (80 in)
Rapid Traverse X	18.0 m/min (710 ipm)
Rapid Traverse Z	8.1 m/min (320 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	MT6
Tailstock Travel	1,930 mm (76 in)
Tailstock Max Thrust	20,017 N (4,500 lbf)
Coolant Capacity	360 L (95 gal)
Machine Weight	14,062 kg (31,000 lb)
CNC Control	Haas Next Generation Control (NGC)

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

Strengths & Limitations

Strengths

12.5-inch spindle bore is the largest in the Haas lineup, handling tubular and hollow workpieces that no other Haas lathe can accept
55 hp spindle producing 4,250 ft-lb of torque at 30 RPM delivers massive material removal capability for heavy roughing in steel, cast iron, and alloy steels
80-inch Z-axis travel with an MT6 tailstock providing 76 inches of travel and 4,500 lbf of thrust supports long shafts and extended tubular components
A1-20 spindle nose with front and rear access enables flexible workholding setups for both chuck work and through-spindle loading
At ~$356K starting, delivers heavy turning capacity that would cost $500K-$800K from European and Japanese builders like Doosan, Okuma, and Mazak

Limitations

1,000 RPM max spindle speed severely limits surface speed on smaller-diameter work — this machine is for large, heavy parts only
Z-axis rapids at 8.1 m/min (320 ipm) are significantly slower than the ST-40/ST-45's 18 m/min, increasing non-cutting time on long traverses
Machine weight of 14,062 kg (31,000 lb) requires heavy-duty foundation preparation, specialized rigging, and may need floor reinforcement
17-inch X-axis travel is 3 inches less than the ST-40/ST-45, limiting cross-slide reach on some configurations
No XP spindle option listed — the 55 hp spindle is the only configuration available

Best For

Oil and gas manufacturers turning large-bore pipe, casing, couplings, and downhole tools requiring 12.5-inch through-bore capacity Power generation and turbine manufacturers machining large shafts, rotors, and cylindrical housings up to 80 inches long Mining and heavy equipment shops turning large pins, rollers, shafts, and wear components in tough materials Shipbuilding and marine manufacturers machining propeller shafts, stern tubes, and large-diameter marine fittings

Frequently Asked Questions

01 What does a new Haas ST-55 cost?

The Haas ST-55 starts at approximately $355,995. Adding tailstock, chip conveyor, high-pressure coolant, and additional tooling pushes the configured price toward $400,000-$430,000. This is the most expensive turning center in the Haas lineup, reflecting its massive capacity and 55 hp spindle.

02 What is the difference between the ST-55 and ST-45?

The ST-55 is a fundamentally larger machine: 12.5-inch bore vs 7.0-inch, 80-inch Z travel vs 44-inch, 55 hp vs 40 hp, 4,250 ft-lb torque vs 1,400 ft-lb, and A1-20 spindle nose vs A2-11. The ST-55 also weighs 31,000 lb vs the ST-45's 22,100 lb. Max spindle speed drops from 1,400 RPM to 1,000 RPM. Choose the ST-55 when the ST-45's bore and Z-travel are insufficient.

03 Can the ST-55 do live tooling and milling?

The base ST-55 uses a 12-station BOT turret without live tooling. For milling capability on this platform size, Haas offers the ST-55Y and ST-55SY variants with Y-axis, live tooling, and C-axis. The standard ST-55 is a pure turning machine focused on heavy material removal.

04 What floor preparation does the ST-55 require?

At 31,000 lb (14,062 kg), the ST-55 requires a reinforced concrete floor, typically 12 inches minimum thickness with rebar, and level to within 0.001 inch per foot. Professional rigging with a crane rated for the machine weight is essential. Consult your Haas HFO dealer for a site survey before purchase.