Star SB-51

$200,000 - $290,000 Updated 2026-03-16

Key Specifications

Rapid Traverse

20 m/min

max bar capacity

51 mm (2.008 in)

max machining diameter

51 mm (2.008 in)

max machining length

320 mm (12.60 in)

main spindle speed

6,000 RPM

back spindle speed

5,000 RPM

Overview

The Star SB-51 is the largest machine in Star Micronics' SB series, offering 51mm bar capacity for heavy-duty Swiss-type production of larger precision components. At 51mm, the SB-51 addresses a market segment where Swiss-type's combination of guide bushing precision and single-setup multi-operation capability delivers genuine advantages over conventional CNC turning for complex longer parts.

The 51mm capacity class is particularly relevant for oil and gas, heavy industrial, and larger medical device applications—sectors that require the surface finish and dimensional consistency of Swiss-type machining but need to work with bar stock diameters beyond the reach of standard Swiss lathes. Components such as large hydraulic valve bodies, actuator shafts, coupling bodies, and implant trials fall naturally within the SB-51's capabilities.

The SB-51's robust machine structure is engineered for the substantial cutting forces generated when working 51mm diameter stock in tough materials. Spindle drives are sized for adequate torque at the lower RPMs appropriate for larger diameters, and the guide bushing system is scaled to maintain the support and precision that are Swiss-type machining's defining characteristics. A Fanuc control provides programming familiarity and broad operator accessibility.

While the SB-51 is positioned as the value tier within Star's 51mm offerings relative to the SH-51, it delivers the core Swiss-type advantages—guide bushing precision, simultaneous front and back operations, and integrated live tooling—in a package optimized for shops where part complexity is moderate but diameter requirements and production volumes justify the Swiss-type approach over conventional turning.

Full Specifications

Parameter	Value
Max Bar Capacity	51 mm (2.008 in)
Max Machining Diameter	51 mm (2.008 in)
Max Machining Length	320 mm (12.60 in)
Main Spindle Speed	6,000 RPM
Back Spindle Speed	5,000 RPM
Live Tool Speed	5,000 RPM
Number Of Axes	6 (X1, Z1, X2, Z2, C1, C2)
Tool Positions	18 (including live tools)
Guide Bushing	Yes
CNC Control	Fanuc 0i-TF
Rapid Traverse Rate	20 m/min
Machine Weight	3,800 kg (8,380 lb)
Power Consumption	18 kVA
Article	3 weeks ago

Strengths & Limitations

Strengths

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Limitations

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Best For

Oil and gas component manufacturers producing hydraulic fittings, valve bodies, and coupling components in the 40-51mm range Medical device manufacturers making large implant trials, instrumentation bodies, and orthopedic components Contract manufacturers seeking Swiss-type precision for 51mm diameter work without the premium of SH-class machines Shops transitioning from conventional turning centers to Swiss-type for medium-complexity large-diameter parts Defense and aerospace suppliers machining actuator components, structural connectors, and hydraulic system parts Industrial component manufacturers requiring consistent finish and tolerances on high-volume 51mm turned parts

Frequently Asked Questions

01 What is the difference between the Star SB-51 and the SH-51?

The SH-51 is Star's premium 51mm Swiss-type with more axes, higher live tool speeds, greater tooling density, and full multi-path synchronized machining capability for complex parts. The SB-51 is the value-tier option with a simpler axis configuration at a lower price point—ideal for medium-complexity parts where the SH-51's additional capability isn't needed.

02 What does a Star SB-51 cost new?

A new Star SB-51 typically ranges from approximately $200,000 to $290,000 depending on configuration and tooling options. Used SB-51 machines sell in the $80,000–$150,000 range depending on age, hours, and condition.

03 Is the Star SB-51 suitable for titanium machining?

Yes, the SB-51's robust construction and adequate spindle torque handle titanium (Ti-6Al-4V and similar alloys) effectively. Appropriate tooling selection—specifically coated carbide inserts designed for titanium—and conservative feed rates are important. The guide bushing system helps maintain precision during the lower cutting speeds required for titanium.

04 What part types are ideal for the SB-51?

The SB-51 excels at parts in the 38-51mm diameter range with L/D ratios up to 6:1 that require Swiss-type precision. Ideal applications include hydraulic valve bodies, large connectors, orthopedic implant components, actuator shafts, and any part needing consistent OD tolerances and surface finish that would be difficult to hold on conventional turning due to part slenderness.

05 How does the SB-51 compare to conventional CNC lathes for 51mm work?

For shorter, simpler parts with adequate rigidity in a conventional chuck, a standard CNC lathe may be faster and less expensive. The SB-51 wins when parts are long relative to diameter (slender), when finish quality must be maintained over the full machined length, or when simultaneous front and back operations in a single setup eliminate costly secondary operations.