Haas ST-45S

$230,000 - $310,000 Updated 2026-03-19

Key Specifications

Max Spindle

1,400 RPM

Spindle Taper

A2-11

Tool Capacity

12-station BOT

Spindle Power

40.0 hp

max part swing

35.5 in

max cutting diameter

27.50 in

Overview

The Haas ST-45S is the sub-spindle variant of the ST-45 large-bore turning center, adding a secondary spindle for back-working operations on large-bore components. It retains the same 178 mm (7.0 in) main spindle bore, A2-11 spindle nose, and 457 mm (18 in) chuck as the standard ST-45, but the sub-spindle enables complete part machining without manual re-chucking.

The main spindle delivers 29.8 kW (40 hp) through a 2-speed gearbox, producing 1,898 Nm (1,400 ft-lb) of torque at 150 RPM with a max speed of 1,400 RPM. The optional XP spindle bumps output to 41.0 kW (55 hp) and 2,847 Nm (2,100 ft-lb). The sub-spindle runs an A2-8 nose, enabling back-end facing, boring, drilling, and threading without removing the part from the machine.

The cutting envelope is 762 mm (30 in) diameter by 1,118 mm (44 in) length on the main spindle side. Axis travels are 508 mm (20 in) in X and 1,118 mm (44 in) in Z, with rapids at 18.0 m/min (710 ipm). The 12-station turret handles both main spindle and sub-spindle operations.

For oil and gas, valve, and heavy industrial shops machining flanged components that require both front and back operations, the ST-45S eliminates the second setup that costs accuracy and time. Pipe couplings with threaded or machined features on both ends are the classic application.

Priced at approximately $230,000-$310,000 configured, the ST-45S commands a premium over the standard ST-45 for the sub-spindle capability, but the reduction in cycle time and elimination of re-chucking operations delivers a strong return on the investment in medium-to-high volume production.

Full Specifications

Parameter	Value
Max Part Swing	35.5 in
Max Cutting Diameter	27.50 in
Max Cutting Length	28.0 in
Chuck Size	18.0 in
Bar Capacity	165 mm (6.5 in) with optional workholding
Spindle Nose	A2-11
Spindle Bore	7.00 in
Max Spindle Speed	1,400 RPM
Spindle Motor Power	40.0 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
Sub Spindle Nose	A2-8
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	5500 lbf
Max Thrust Z	9000 lbf
Tool Capacity	12-station BOT
Tailstock Taper	MT5
Coolant Capacity	95 gal
Machine Weight	20400 lb
CNC Control	Haas Next Generation Control (NGC)
Capacities	S.A.E
Chuck	18.0 in
Bar Capacity W Opt Workholding	6.50 in
Travels	S.A.E
X Axis	20.00 in
Z Axis	28.00 in
Feedrates	S.A.E
Rapids On X	710 ipm
Rapids On Z	710 ipm
Axis Motors	S.A.E
Spindle	S.A.E
Spindle Taper	A2-11
Drive System	2-Speed Gearbox
Max Rating	55.0 hp
Max Speed	1400 rpm
Max Torque	2100.0 ft-lbf @ 150 rpm
Xp Option	S.A.E
Input Ac Voltage Low	220 VAC
Full Load Amps Low	70 A
Input Ac Voltage High	440 VAC
Full Load Amps High	35 A
Pc18kit	S.A.E
Draw Tube Bore	6.50 in
Tailstock	S.A.E
Taper	MT5
Travel	26.0 in
Max Thrust	3,000 lbf
Min Thrust	200 lbf
Turret	S.A.E
Od Vs Id Tools	Any Combination (will vary with turret)
Boring Bar Rear Clearance	4.50 in
Tooling	BOT
General	S.A.E
Air Requirements	S.A.E
Air Required	4 scfm @ 100 psi
Inline Air Hose	3/8 in
Coupler	3/8 in
Air Pressure Min	80 psi
Electrical Specification	S.A.E
Dimensions Shipping	S.A.E
Domestic Pallet	216.5 in x 94.5 in x 116.0 in
Export Crate	216.5 in x 96.0 in x 120.0 in

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

Strengths & Limitations

Strengths

Sub-spindle enables done-in-one machining of large-bore components, eliminating re-chucking and second-operation accuracy loss
Same 7.0-inch main spindle bore and A2-11 nose as the ST-45 for full large-bore through-spindle capability
40 hp main spindle with 1,400 ft-lb torque handles heavy roughing on front and back operations
A2-8 sub-spindle nose provides robust clamping for back-end facing, boring, and threading
Optional XP spindle upgrade to 55 hp and 2,100 ft-lb for the most demanding roughing applications
Eliminates double-handling and re-fixturing costs that add up quickly in medium-to-high volume production

Limitations

1,400 RPM max spindle speed limits surface speed on smaller-diameter work and aluminum finishing
Sub-spindle adds significant cost over the standard ST-45 — the premium is justified only with sufficient volume
Machine weight of approximately 24,000 lb requires heavy-duty rigging and floor preparation
Sub-spindle cuts into available Z-axis working length for main spindle operations

Best For

Oil and gas manufacturers machining pipe couplings, flanges, and fittings that require operations on both ends Valve body manufacturers needing front and back boring, facing, and threading in a single setup Medium-to-high volume production where eliminating re-chucking delivers measurable cycle time savings Heavy industrial shops machining large-bore components with tight concentricity requirements between front and back features Shops upgrading from a standard ST-45 where second-operation re-chucking is a bottleneck

Frequently Asked Questions

01 What does a new Haas ST-45S cost?

The ST-45S starts at approximately $230,000. With the XP spindle, BMT75 live tooling, high-pressure coolant, and chip conveyor, configured prices reach $280,000-$310,000. The sub-spindle premium over the standard ST-45 is approximately $40,000-$50,000.

02 What is the sub-spindle specification on the ST-45S?

The sub-spindle runs an A2-8 nose for back-end operations including facing, boring, drilling, and threading. It enables complete part machining by receiving the workpiece from the main spindle for back-working, eliminating the need for manual re-chucking.

03 How does the ST-45S compare to the standard ST-45?

The ST-45S adds a sub-spindle with an A2-8 nose for back-working operations. The main spindle, bore size, cutting envelope, and power specs are identical. Choose the ST-45S when parts require machined features on both ends and production volume justifies the sub-spindle premium.

04 Can the ST-45S do live tooling?

Yes, with the optional BMT75 turret and C-axis. Live tooling at 4,000 RPM combined with the sub-spindle creates a versatile large-bore mill-turn platform for complex components requiring turning, milling, and back-working in a single setup.