Star Micronics SV-20R

$220,000 - $360,000 Updated 2026-03-14

Key Specifications

Max Spindle

10,000 min-1

Spindle Power

3.7kW (continuous) / 5.5kW (10min. / 60%ED)

Max Turn Length

205mm (8in)

max machining diameter

20 mm (25/32 in), optional 23 mm (29/32 in)

max headstock stroke

205 mm (8 in)

max front ejection length

105 mm (4-9/64 in)

Overview

The Star Micronics SV-20R is the high-performance flagship of Star's 20mm Swiss-type lathe lineup, combining the flexibility of both gang-type and turret-type tooling on a single platform. The SV designation—high-performance—signals that this machine is engineered for shops that demand the fastest cycle times, most complex parts, and highest precision available in a 20mm sliding headstock lathe. It is the machine that pushes the boundaries of what Swiss-type turning can accomplish.

The main spindle delivers 3.7 kW continuous power (5.5 kW peak) at 10,000 RPM—70% more continuous power than the SR-20JII's 2.2 kW. The sub spindle provides 2.2 kW continuous (3.7 kW peak) at 10,000 RPM. The optional 23mm bar capacity extends the reach for shops handling slightly larger parts. The back 8-spindle unit runs power-driven tools at up to 8,000 RPM with up to 8 stationary and 8 power-driven positions, providing comprehensive back-working capability.

What makes the SV-20R unique is its hybrid tooling approach. The machine combines gang-type front tools (6 tools at 16mm shank or 7 at 12mm) with turret-type capability (1 tool per station at 16mm or up to 3 tools per station at 12mm). This dual approach gives programmers the speed advantage of gang-type tool changes for primary operations plus the capacity of turret indexing for secondary operations—the best of both worlds.

Running on the FANUC 31i-B5 control, the SV-20R provides the processing power needed for complex multi-path programs. At 4,150 kg and a footprint of 2,730 x 1,350 mm, it is larger than the SR-20JII but more compact than the ST-20, occupying a middle ground. The switchable guide bush / non-guide bush capability and maximum headstock stroke of 205mm complete the package. The 6.3 kVA power consumption is moderate for a high-performance machine.

Full Specifications

Parameter	Value
Max Machining Diameter	20 mm (25/32 in), optional 23 mm (29/32 in)
Max Headstock Stroke	205 mm (8 in)
Max Front Ejection Length	105 mm (4-9/64 in)
Max Part Projection	75 mm (2-16/64 in)
Main Spindle Speed	10,000 RPM
Main Spindle Power	3.7 kW continuous / 5.5 kW (10 min, 60% ED)
Sub Spindle Speed	10,000 RPM
Sub Spindle Power	2.2 kW continuous / 3.7 kW (10 min, 40% ED)
Gang Type Tools	6 tools (16 mm) or 7 tools (12 mm)
Turret Type Tools	1 tool/station (16 mm) or 3 tools/station (12 mm)
Back 8 Spindle Stationary	8 tools
Back 8 Spindle Power Driven	Max 8 tools at 8,000 RPM
Guide Bushing	Switchable (guide bush / non-guide bush)
CNC Control	FANUC 31i-B5
Power Consumption	6.3 kVA
Machine Weight	4,150kg
Dimensions	2,730 x 1,350 x 1,865 mm
Max Turning Diameter	ø20mm (25/32in)
Max Turning Length	205mm (8in)
Bar Capacity	ø50mm (1-31/32in)
Turret Stations	8 stations
Max Spindle Speed	10,000 min-1
Spindle Motor Power	3.7kW (continuous) / 5.5kW (10min. / 60%ED)
Coolant Capacity	220ℓ
Cnc Control	FANUC 31i-B5
Floor Space	2,730 x 1,350 x 1,865mm
Electrical	6.3KVA

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

Strengths & Limitations

Strengths

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Limitations

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Best For

Medical device manufacturers producing the most complex implants and instruments where cycle time optimization directly impacts profitability Aerospace precision shops producing multi-feature fittings, valve bodies, and actuator components with tight tolerances and demanding surface finish requirements High-volume automotive component manufacturers where the SV-20R's power and tooling advantages translate directly into faster cycle times and lower per-part costs Contract shops handling premium work where the ability to complete complex parts in one cycle eliminates secondary operations and improves quality Shops upgrading from SR-20JII that have hit the limits of 2.2 kW spindle power or gang-only tooling capacity Any application where the SV-20R's cycle time improvement over the SR-20JII produces a positive ROI within the machine's payback period

Frequently Asked Questions

01 What does a Star Micronics SV-20R cost?

A new Star SV-20R typically runs $220,000-$360,000 depending on tooling configuration, back-unit options, and bar feeder. This positions it as the premium 20mm Swiss lathe in Star's range, above the SR-20JII but offering substantially more capability. Used SV-20R machines trade for $130,000-$220,000 when available.

02 How does the SV-20R compare to the SR-20R IV?

Both are premium 20mm platforms with FANUC 31i-B5 controls. The SR-20R IV emphasizes maximum tool positions (41 tools) and B-axis capability. The SV-20R emphasizes hybrid gang+turret tooling and higher spindle power (3.7 kW vs 2.2 kW). Choose the SR-20R IV for parts needing B-axis angular features; choose the SV-20R for parts needing power and hybrid tooling flexibility.

03 What is the advantage of the hybrid gang + turret approach?

Gang-type tool changes are essentially instantaneous—the machine simply moves axes to the next tool position. Turret changes require indexing time but offer more positions. The SV-20R lets programmers assign the most frequently used tools to gang positions for speed, while using turret positions for less frequent operations or additional tool capacity. This optimizes cycle time without sacrificing tool count.

04 Is the SV-20R worth the premium over the SR-20JII?

It depends on your application. If your parts require more than 2.2 kW spindle power, benefit from the hybrid tooling approach, or need extensive back-working capability, the SV-20R's premium pays for itself through faster cycle times and eliminated secondary operations. For simpler parts where the SR-20JII's capability is sufficient, the premium may not be justified.

05 Can the SV-20R handle back-end milling operations?

Yes. The back 8-spindle unit accommodates up to 8 power-driven tools running at 8,000 RPM, supporting cross-drilling, cross-milling, back-end threading, and contour machining on the sub spindle. This is one of the most capable back-working units in the 20mm Swiss class.

06 What is the difference between 16mm and 12mm tool shanks?

16mm shanks provide more rigidity for heavier cuts on larger diameters and harder materials, but take up more space in the tool post (6 positions). 12mm shanks allow one additional tool position (7 total) and are adequate for lighter cuts and smaller diameters. Most shops producing 15-20mm parts in steel or stainless use 16mm shanks for maximum rigidity.