Star SB-20R Type G

Est. $120,000 - $200,000 Specs verified 2026-10-03 · ellisontechnologies.com Updated 2026-10-03

Image: starcnc.com, Star Micronics

Key Specifications

Max Spindle

6,000 rpm

Tool Capacity

6 tools (ø12mm) / 7 tools (ø10mm)

Rapid Traverse

35 m/min (X1,Y1,Z1,X2,Z2)

Spindle Power

2.2 kW (Continuous) / 3.7 kW (10min./25%ED)

Max Turn Length

80mm (3-5/32in)

max machining diameter

20 mm (0.787 in)

How much does the Star SB-20R Type G cost?

Estimated price range

Est.$120,000 - $200,000

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 SB-20R Type G is a Swiss-type sliding-headstock lathe for bar up to 20 mm (25/32 in), listed with 7 axes, a 205 mm (8 in) headstock stroke and a machine weight of 1,700 kg. It is the largest of three Type G machines with closely matched tables. The SB-16R Type G takes ø16mm (5/8in) bar and the SB-12R Type G takes Ø13 mm (33/64 in), and both show the same 6,000 rpm spindle figure and 35 m/min rapid traverse as this model.

The two spindles are not equals. The main spindle is listed at 6,000 rpm with 2.2 kW continuous and 3.7 kW on the 10min./25%ED rating. The sub spindle runs faster, to 9,000 rpm, on a far smaller motor: 0.55 kW continuous and 1.1 kW on the 15min./40%ED rating. Read together, those rows say that stock removal belongs on the main side, while the sub spindle is sized for light back-end turning, drilling and finishing after cut-off.

Turning tools can be arranged in one of two ways, 6 tools on 12 mm shanks or 7 tools on 10 mm shanks, so the choice is between a stiffer shank and one more station. Rapid traverse is 35 m/min on X1, Y1, Z1, X2 and Z2.

The machine occupies 2,070 mm × 1,177 mm × 1,760 mm, which leaves the bar feeder as the main thing to add when planning floor space. The SB-20RII is the heavier relative at Approx. 2,000kg, with a spindle listed at Max. 10,000min-1 and an optional ø25.4mm (1in) bar size.

Full Specifications

Parameter	Value
Max Machining Diameter	20 mm (0.787 in)
Number of Axes	7
CNC Control	Fanuc 31i-B
Rapid Traverse Rate	35 m/min (X1,Y1,Z1,X2,Z2)
Machine Weight	1,700 kg
Power Consumption	8 kVA
Max Turning Diameter	ø20mm (25/32in)
Max Turning Length	80mm (3-5/32in)
Bar Capacity	Ø20 mm (25/32 in)
Max Spindle Speed	6,000 rpm
Spindle Motor Power	2.2 kW (Continuous) / 3.7 kW (10min./25%ED)
Tool Capacity	6 tools (ø12mm) / 7 tools (ø10mm)
CNC Control	Fanuc 0i-TD
Electrical	3.7KVA
Headstock Stroke	205 mm (8 in)
Sub Spindle Speed	9,000 rpm
Sub Spindle Power	0.55 kW (Continuous) / 1.1 kW (15min./40%ED)
Turning Tools	6 tools (□12 mm) / 7 tools (□10 mm)
Floor Space Required	2,070 mm × 1,177 mm × 1,760 mm

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

Strengths & Limitations

Strengths

205 mm (8 in) of headstock stroke on a 20 mm (25/32 in) bar machine
Sub spindle listed at 9,000 rpm for back-end work, with 0.55 kW continuous and 1.1 kW on the 15min./40%ED rating
Turning tools can be set up as 6 tools on 12 mm shanks or 7 tools on 10 mm shanks
35 m/min rapid traverse on X1, Y1, Z1, X2 and Z2
Small installation: 2,070 mm × 1,177 mm × 1,760 mm and 1,700 kg

Limitations

The main spindle is listed at 6,000 rpm, against Max. 10,000min-1 on the SB-20RII, which holds back surface speed on small diameters
Sub spindle power is 0.55 kW continuous, a quarter of the 2.2 kW on the main spindle, so back-end cuts have to stay light
Bar size stops at 20 mm (25/32 in) with no oversize option in the table, where the SB-20RII lists ø25.4mm (1in) as an option
The table gives no driven-tool count, speed or power, so cross-drilling and milling capacity has to be confirmed separately

Best For

Bar work up to 20 mm (25/32 in) in diameter Parts that need up to 205 mm (8 in) of headstock stroke Parts finished complete with light back-end cuts on the 9,000 rpm sub spindle Cells where a 2,070 mm × 1,177 mm machine has to fit between others

Frequently Asked Questions

01 What bar diameter does the Star SB-20R Type G take?

Up to 20 mm (25/32 in). The table shows no larger optional size. Within the same family the SB-16R Type G is listed at ø16mm (5/8in) and the SB-12R Type G at Ø13 mm (33/64 in), so the SB-20R is the one to pick when any part in the mix needs stock above 16 mm.

02 How do the main and sub spindles compare?

The main spindle is listed at 6,000 rpm with 2.2 kW continuous and 3.7 kW on the 10min./25%ED rating. The sub spindle is listed at 9,000 rpm with 0.55 kW continuous and 1.1 kW on the 15min./40%ED rating. The sub spindle is faster but has a quarter of the continuous power, so plan the heavy cuts for the main side.

03 How many turning tools does it hold?

Either 6 tools on 12 mm shanks or 7 tools on 10 mm shanks. The smaller shank buys one extra station, the larger one gives a stiffer tool. The table does not list driven tools, so ask for the cross-working and back-working tool configuration when you request a quotation.

04 How much floor space and floor load does it need?

The machine itself measures 2,070 mm × 1,177 mm × 1,760 mm and weighs 1,700 kg. Those figures cover the lathe only. A bar feeder, chip handling and coolant equipment sit outside them and should be added to the layout before the position is fixed.

05 What is the difference between the SB-20R Type G and the SB-20RII?

The SB-20RII is listed with a spindle of Max. 10,000min-1 against 6,000 rpm here, an optional ø25.4mm (1in) bar size, and a weight of Approx. 2,000kg against 1,700 kg. Both show 35 m/min rapid traverse and a 2.2 kW continuous main spindle rating.