Star Micronics SW-12RII

Est. $140,000 - $230,000 Specs verified 2026-10-03 · ellisontechnologies.com Updated 2026-10-03

Image: starcnc.com, Star Micronics

Key Specifications

Max Spindle

15,000 rpm

Tool Capacity

Front 5 tools, Rear 2 tools

Rapid Traverse

35 m/min (for X2, Y1, Y3, Z1, Z2 axes)

Spindle Power

2.2 kW (continuous) / 3.7 kW (10min/25%ED)

max machining diameter

13 mm (33/64 in)

max headstock stroke standard

135 mm (5-5/16 in)

How much does the Star Micronics SW-12RII cost?

Estimated price range

Est.$140,000 - $230,000

Our best estimate for a swiss-type lathe in this class — not a quote from Star Micronics. Configuration moves it a long way.

Overview

The Star Micronics SW-12RII is a small-diameter Swiss-type lathe: Ø13 mm (33/64 in) bar, a 135 mm (5-5/16 in) headstock stroke and 15,000 rpm on both the main and the sub spindle. It is the smaller of the two SW machines; the SW-20 takes Ø20 mm (25/32 in) bar at 10,000 rpm.

Speed is the point of this size. On 13 mm stock, and on the much smaller diameters usually turned from it, 15,000 rpm is what keeps surface speed up, and having the same ceiling on the sub spindle means the back end of the part is not cut slower than the front. Motor ratings are 2.2 kW (continuous) / 3.7 kW (10min/25%ED) for the main spindle and 2.2 kW (continuous) / 3.7 kW (10min./40%ED) for the sub spindle.

The back-working side is unusually well equipped for a machine this small. A back 8-spindle unit takes up to 8 stationary tools plus 8 power-driven tools, so drilling, tapping and milling on the cut-off face do not have to share a handful of positions. At the front there are 5 turning tools with 2 rear tools, on 10 mm shanks, and a 4-spindle sleeve holder with 4 front and 4 rear tools. The table also lists a maximum part projection of 20 mm (25/32 in); ask the dealer which spindle that limit applies to before planning long back-end work.

Rapid traverse depends on the axis: 35 m/min on X2, Y1, Y3, Z1 and Z2, 24 m/min on X1 and X3, and 15 m/min on Y2. The machine weighs 2,100 kg and its footprint row reads 1,995 × 920 × 1,700 mm.

Full Specifications

Parameter	Value
Max Machining Diameter	13 mm (33/64 in)
Max Headstock Stroke Standard	135 mm (5-5/16 in)
Max Part Projection	20 mm (25/32 in)
Sub Spindle Speed	15,000 rpm
Sub Spindle Power	2.2 kW (continuous) / 3.7 kW (10min./40%ED)
Front Tools	5 tools + 2 rear tools (10 mm shank)
Sleeve Holder	4-spindle (front 4 / rear 4 tools)
Back 8 Spindle Unit	Max 8 stationary + 8 power-driven tools
Rapid Feed Rate	35 m/min (X2, Y1, Y3, Z1, Z2), 24 m/min (X1, X3), 15 m/min (Y2)
Machine Weight	2,100 kg
Max Turning Diameter	ø13mm (33/64in)
Bar Capacity	Ø13 mm (33/64 in)
Max Spindle Speed	15,000 rpm
Spindle Motor Power	2.2 kW (continuous) / 3.7 kW (10min/25%ED)
Tool Capacity	Front 5 tools, Rear 2 tools
Headstock Stroke	135 mm (5-5/16 in)
Turning Tools	Front: 5 tools - Rear: 2 tools
Rapid Traverse Rate	35 m/min (for X2, Y1, Y3, Z1, Z2 axes)
Floor Space Required	1,995 × 920 × 1,700 mm

Specifications sourced from ellisontechnologies.com (authorised dealer / distributor, not the manufacturer's own site) — verified 2026-10-03

Strengths & Limitations

Strengths

15,000 rpm on both the main and the sub spindle, so small diameters can be cut at speed on either end of the part
Back 8-spindle unit takes up to 8 stationary tools plus 8 power-driven tools for work on the cut-off side
35 m/min rapid traverse on X2, Y1, Y3, Z1 and Z2
5 front turning tools and 2 rear tools on 10 mm shanks, plus a 4-spindle sleeve holder with 4 front and 4 rear tools
Weighs 2,100 kg with a 1,995 × 920 × 1,700 mm footprint; the SW-20 is listed at 3,400 kg

Limitations

Bar capacity stops at Ø13 mm (33/64 in); the SW-20 takes Ø20 mm (25/32 in)
Headstock stroke is 135 mm (5-5/16 in) as standard, which caps the length turned in one chucking
Y2 rapid traverse is 15 m/min and X1 and X3 run at 24 m/min, below the 35 m/min of the other listed axes
Main spindle power is 2.2 kW continuous, with 3.7 kW only on the 10min/25%ED rating, so heavy stock removal in tough alloys is outside its range

Best For

Small-diameter bar work up to Ø13 mm (33/64 in) Parts with heavy back-end content, using up to 8 power-driven tools on the back unit Small turned parts that need 15,000 rpm on both spindles Slender parts within the 135 mm (5-5/16 in) headstock stroke

Frequently Asked Questions

01 What bar diameter and part length can the SW-12RII handle?

Maximum machining diameter and bar capacity are Ø13 mm (33/64 in). The standard headstock stroke is 135 mm (5-5/16 in), which sets the length that can be turned in one chucking. A maximum part projection of 20 mm (25/32 in) is also listed.

02 Are the main and sub spindles on the SW-12RII the same?

In speed, yes: both are listed at 15,000 rpm. Both also show 2.2 kW continuous and a 3.7 kW short-time figure, but the duty rating differs between the rows. The main spindle row reads 3.7 kW (10min/25%ED) and the sub spindle row reads 3.7 kW (10min./40%ED).

03 How many tools does the SW-12RII carry?

The front post holds 5 turning tools with 2 rear tools, all on 10 mm shanks. A 4-spindle sleeve holder adds 4 front and 4 rear tools. For the sub spindle, the back 8-spindle unit takes a maximum of 8 stationary tools plus 8 power-driven tools.

04 What are the rapid traverse rates on the SW-12RII?

They vary by axis. X2, Y1, Y3, Z1 and Z2 move at 35 m/min, X1 and X3 at 24 m/min, and Y2 at 15 m/min. The slower axes matter mostly on short-cycle parts, where tool-to-tool positioning is a visible share of the cycle.

05 How does the SW-12RII differ from the SW-20?

The SW-20 is the larger machine: Ø20 mm (25/32 in) bar against Ø13 mm (33/64 in), 10,000 rpm against 15,000 rpm, and 3,400 kg against 2,100 kg. The SW-20 lists the same 2.2 kW (continuous) / 3.7 kW (10min/25%ED) main spindle power, and Front 4 tools / Rear 2 tools where the SW-12RII has front 5 tools and rear 2 tools.