Star SB-20R Type G

$120,000 - $200,000 Updated 2025-03-15

Key Specifications

Max Spindle

max. 10,000min-1

Tool Capacity

6 tools (ø12mm) / 7 tools (ø10mm)

Rapid Traverse

32 m/min

Spindle Power

2.2kw (continuous) / 3.7kw (10min./25%ED)

Max Turn Length

80mm (3-5/32in)

max bar capacity

20 mm (0.787 in)

Overview

The Star SB-20R Type G is a versatile 20mm Swiss-type CNC automatic lathe that combines the SB series' value orientation with expanded capability through the 'R' (Revised) platform and Type G guide bushing configuration. This machine targets the high-volume 20mm bar size sweet spot where the largest concentration of Swiss-type work exists across medical, electronics, automotive, and aerospace industries. The Type G designation indicates the standard guide bushing configuration, optimizing the machine for the precision and surface finish that guide bushing Swiss turning is known for.

With up to 7 axes and an expanded tool layout compared to the smaller SB-16 variants, the SB-20R Type G delivers meaningfully more capability while maintaining the SB series' emphasis on value and operational simplicity. The main spindle reaches 10,000 RPM with a built-in motor design for smooth, vibration-free rotation, while the back spindle provides capable secondary machining at 8,000 RPM. The gang-type tool post accommodates up to 22 tool positions, providing enough stations for multi-feature parts without the complexity of a turret-based system.

Star's guide bushing technology is at the heart of the SB-20R Type G's precision capability. The guide bushing supports the bar stock immediately adjacent to the cutting zone, eliminating deflection and enabling tight tolerances even on longer parts. This is particularly valuable at the 20mm bar size where workpiece rigidity becomes more critical than on smaller-diameter Swiss work. The Fanuc 31i-B control provides reliable, familiar CNC operation with support for advanced features like superimposed control and custom macro programming.

The SB-20R Type G occupies a strategic position in Star's lineup: more capable than the 16mm SB models and significantly more affordable than the SR-20J or SV-20. For shops whose parts fit within the SB platform's capability envelope, this machine delivers an excellent balance of Swiss precision, production capability, and capital efficiency. Star's global service network and parts availability ensure long-term support and minimized downtime.

Full Specifications

Parameter	Value
Max Bar Capacity	20 mm (0.787 in)
Max Machining Diameter	20 mm (0.787 in)
Max Machining Length	200 mm (7.87 in)
Main Spindle Speed	10,000 RPM
Back Spindle Speed	8,000 RPM
Number Of Axes	7
Tool Positions	22
Guide Bushing	Yes (Type G standard)
CNC Control	Fanuc 31i-B
Rapid Traverse Rate	32 m/min
Machine Weight	1,750kg
Power Consumption	8 kVA
Max Turning Diameter	ø20mm (25/32in)
Max Turning Length	80mm (3-5/32in)
Bar Capacity	ø20mm (25/32in)
Max Spindle Speed	max. 10,000min-1
Spindle Motor Power	2.2kw (continuous) / 3.7kw (10min./25%ED)
Tool Capacity	6 tools (ø12mm) / 7 tools (ø10mm)
Rapid Traverse X	35m/min
Rapid Traverse Y	35m/min
Rapid Traverse Z	35m/min
Coolant Capacity	180ℓ
Floor Space	2,070 × 1,177 × 1,760mm
Cnc Control	Fanuc 0i-TD
Electrical	3.7KVA

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

Strengths & Limitations

Strengths

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Limitations

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Best For

Shops needing 20mm Swiss capability at a value price point without requiring SR or SV-level complexity High-volume production of turned components in the 10-20mm range for medical, automotive, and electronics industries Contract manufacturers adding 20mm Swiss capacity for moderately complex turned parts Automotive suppliers producing fuel system components, sensor housings, and precision fittings Shops running multiple Swiss lathes that want to standardize on Star's SB platform for simpler part families

Frequently Asked Questions

01 What does a Star SB-20R Type G cost?

A new Star SB-20R Type G typically costs between $120,000 and $200,000 depending on configuration and options. This is roughly 30-40% less than a comparably equipped SR-20J. Used SB-20R machines sell for $40,000-$100,000 depending on age, condition, and tooling.

02 What does Type G mean on the SB-20R?

Type G indicates the guide bushing configuration. The SB-20R Type G is set up for standard guide bushing operation, which provides maximum precision and surface finish for Swiss-type turning. Star also offers Type N (non-guide bushing) configurations for some models, which are better suited for short parts where bar remnant waste is a concern.

03 How does the SB-20R compare to the SR-20J?

The SR-20J is significantly more capable with Y-axis, more live tooling, up to 9 axes, and greater configuration flexibility. The SB-20R Type G is designed for shops whose parts are primarily turned with moderate cross-work and don't require the SR-20J's milling capability. The SB-20R costs 30-40% less, making it the better value when parts fit its capability.

04 Can the SB-20R Type G handle medical parts?

Yes, for simpler medical components. Bone screws, dental abutment blanks, cannulated pins, and basic surgical instrument shafts are well within its capability. Complex medical parts with flats, hexagons, and angular features are better suited to the SR-20J or SV-20.

05 What bar feeder works with the SB-20R Type G?

The SB-20R Type G is compatible with standard magazine and hydrodynamic bar feeders from LNS, FMB, IEMCA, and other major manufacturers. Star can specify the optimal bar feeder integration for your production requirements. Most shops use a 12-foot magazine feeder for maximum unattended run time.