SNK RB-Series

$800,000 - $1,600,000 Updated 2026-03-16

Key Specifications

X Travel

4,000 mm (157.5 in) standard

Y Travel

2,500 mm (98.4 in)

Z Travel

1,200 mm (47.2 in)

Max Spindle

3,000 RPM

Table Size

1,800 mm x 1,800 mm (70.9 in x 70.9 in)

Spindle Power

37 kW (49.6 HP)

Overview

The SNK RB-Series is a floor-type CNC horizontal boring and milling machine designed for heavy-duty machining of large, complex workpieces. Built on SNK's decades of experience supplying floor-type boring equipment to shipbuilding, heavy equipment, and energy sector manufacturers in Japan and globally, the RB-Series features a rigid box-column construction and a large floor-mounted rotary table accommodating workpieces up to 1,800 mm in width. The machine is engineered for precision boring, facing, and milling on castings, forgings, and fabrications that cannot be processed on conventional machining centers.

The RB-Series spindle accepts a 130 mm (5.12 in) boring bar with a maximum spindle speed of 3,000 RPM and a spindle power of 37 kW (49.6 HP). The floor-type column travels on precision-ground box guideways in X (column traverse), while Y (vertical) and Z (spindle advance) provide the three primary linear axes. A CNC W-axis quill extends the boring bar for deep-bore operations without repositioning the column. Table rotation (B-axis) is CNC-controlled in 0.001-degree increments for 4-axis positioning.

SNK equips the RB-Series with the Fanuc 30i-B control, providing full 4-axis simultaneous interpolation and optional 5-axis capability with an angular milling head attachment. The machine's large floor area and high table load capacity — up to 30,000 kg on the floor and rotary table combined — make it a preferred choice for shipbuilding yards, power generation OEMs, and industrial machinery manufacturers needing to process large one-off or short-run components. Thermal compensation, full enclosure, and high-pressure coolant through spindle are available as options.

Pricing for the SNK RB-Series typically ranges from $800,000 to $1,600,000 depending on table size, spindle diameter, and axis configuration selected.

Full Specifications

Parameter	Value
Spindle Diameter	130 mm (5.12 in)
Max Spindle Speed	3,000 RPM
Spindle Motor Power	37 kW (49.6 HP)
Table Size	1,800 mm x 1,800 mm (70.9 in x 70.9 in)
Table Load Capacity	30,000 kg (66,139 lb)
X-Axis Travel	4,000 mm (157.5 in) standard
Y-Axis Travel	2,500 mm (98.4 in)
Z-Axis Travel	1,200 mm (47.2 in)
Quill Stroke W	500 mm (19.7 in)
B Axis Resolution	0.001 degrees
Positioning Accuracy	±0.008 mm (±0.00031 in)
CNC Control	Fanuc 30i-B
Machine Type	Machining Center
Num Of Axes	4
Operation Type	CNC
Cnc Brand	Fanuc 31i
Table Size L X W	157.500(L) x 78.740(W)
Table Size L X W Opt	236.220(L) x 78.740(W)
Max Workpiece Weight	33,000
Direction	Combination
Taper	# 50
Top Rpm	6,000
Top Rpm Opt	4,500
Hp	30.00
Hp Opt	50.00
Tool Carrier	ATC
Num Tools	40
Num Tools Opt	120
Tool Change Chip Time	0.00
Pallet Changer Available	Optional
Num Pallets	2
Num Axes	4
Num Axes Opt	5
U Axis	None
X1	167.300" Opt: 285.430"
Y1	114.000"
Z1	23.600"

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

Strengths & Limitations

Strengths

Floor-type design with a 30,000 kg table load capacity enables machining of very large castings and fabrications that would exceed the capacity of any machining center
130 mm spindle with 37 kW power provides sustained cutting force for heavy boring passes in steel, cast iron, and Inconel without deflection
CNC B-axis table rotation to 0.001-degree resolution enables precise 4-axis positioning for multi-face machining without workpiece unclamping
Fanuc 30i-B control offers broad compatibility with existing shop CAM and DNC infrastructure, reducing programming overhead for new jobs

Limitations

Floor-type setup requires substantial site preparation including foundation, coolant trenches, and enclosure — adding months to initial installation
Lower maximum spindle speed (3,000 RPM) compared to machining centers limits the machine's suitability for high-speed finish milling of aluminum and light alloys
Long cycle times for repositioning the large floor-type column reduce throughput compared to fixed-column machining centers on medium-sized workpieces

Best For

Shipbuilding and marine equipment manufacturers machining large structural frames, engine blocks, and gearbox housings requiring precision boring on multiple faces Power generation OEMs processing large turbine casings, generator frames, and valve bodies where workpiece weight exceeds 5,000 kg Heavy equipment manufacturers boring axle housings, transmission cases, and hydraulic manifold blocks in one setup Job shops and contract manufacturers servicing the energy and defense sectors with large, one-off precision boring requirements

Frequently Asked Questions

01 What is the difference between the SNK RB-Series and a machining center for large parts?

The RB-Series is a floor-type boring mill where the workpiece sits on a large floor-mounted rotary table and the column travels to the work. This allows machining of workpieces that are too large and heavy for any machining center pallet system — the 30,000 kg floor load capacity and 1,800 mm table far exceed what any standard HMC can handle. Machining centers excel at higher spindle speeds and automated pallet changing for medium-size parts; the RB-Series is built for large, heavy, one-of-a-kind workpieces.

02 Can the RB-Series perform milling operations in addition to boring?

Yes. The RB-Series spindle accommodates a full range of milling cutters, shell mills, and boring heads via its ISO 50 or HSK-A100 spindle interface. Face milling, pocket milling, and contouring are all standard operations. An optional angular milling head extends the machine to 5-axis positioning, enabling compound-angle milling on parts that would otherwise require multiple setups.

03 What control system does the RB-Series use?

The RB-Series is equipped with the Fanuc 30i-B CNC controller, which provides 4-axis simultaneous interpolation as standard. The 30i-B supports advanced features including thermal compensation, look-ahead control for smooth contour milling, and high-speed program processing. It is compatible with standard EIA/ISO G-code programs and most major CAM postprocessors.

04 How does the CNC W-axis quill work on the RB-Series?

The W-axis is the CNC-controlled spindle quill that extends the boring bar axially from the spindle face without moving the Z-axis column. It provides 500 mm (19.7 in) of additional reach for deep-bore operations, allowing the machine to reach features inside a deep casting without repositioning the column. The quill is CNC-programmed and can be used simultaneously with the other linear axes for boring taper and stepped bore profiles.

05 What industries use the SNK RB-Series?

Primary users are shipbuilding yards machining structural components, marine engine parts, and propulsion system housings; power generation manufacturers producing turbine casings and generator frames; and heavy industrial equipment OEMs machining large gearboxes, compressor cases, and hydraulic components. Defense contractors and large-part job shops are also common users.