DMG Mori SL-403

5,000 - 0,000 (used) Updated 2026-03-13

Key Specifications

Max Spindle

4,000 RPM

Tool Capacity

12 stations (driven tools optional)

Rapid Traverse

24 m/min (945 ipm) X, 24 m/min (945 ipm) Z

Spindle Power

18.5 kW (24.8 hp)

Max Turn Length

610 mm (24.0 in)

max turning diameter

410 mm (16.1 in)

Overview

The DMG Mori SL-403 (originally Mori Seiki SL-403) is a mid-size slant bed CNC lathe that has earned a legendary reputation among machinists for its rock-solid construction and long service life. Produced from the early 2000s through the mid-2010s, the SL-403 was one of Mori Seiki’s most popular turning centers and remains highly sought-after on the used market. If you see one on a shop floor that has been running for 15+ years with original spindle bearings, that tells you everything about the build quality.

The main spindle delivers 18.5 kW (24.8 hp) at 4,000 RPM with 610 Nm (450 ft-lb) of torque through an A2-8 spindle nose. The standard 10-inch (254 mm) chuck handles most production chucking work, with bar capacity of 76 mm (3.0 in) through the spindle bore. Maximum turning diameter is 410 mm (16.1 in) with 610 mm (24.0 in) of turning length, covering the bulk of mid-size shaft and chuck work.

The SL-403 uses box guideways on both X and Z axes, which is a key reason for its superior surface finish quality and vibration damping compared to linear-guide competitors from the same era. The 12-station turret accepts VDI 40 tooling with optional driven tools for cross-drilling, tapping, and light milling. The optional C-axis enables angular positioning for milled features.

The machine was available with MSC-501 (Mitsubishi-based) or MAPPS IV controls. Earlier versions used the MSC-500 series. The controls are reliable but lack the touchscreen interfaces of modern CELOS machines. Programming is straightforward G-code with Mori Seiki conversational overlay.

New SL-403 machines are no longer produced (replaced by the NLX lineup), but used units from 2003-2015 trade between 5,000 and 0,000 depending on hours, condition, and options. At these prices, a well-maintained SL-403 delivers more rigidity and build quality per dollar than any new entry-level lathe on the market. Parts availability is good through DMG Mori and aftermarket suppliers.

Full Specifications

Parameter	Value
Max Turning Diameter	410 mm (16.1 in)
Max Turning Length	610 mm (24.0 in)
Max Spindle Speed	4,000 RPM
Spindle Motor Power	18.5 kW (24.8 hp)
Spindle Torque	610 Nm (450 ft-lb)
Spindle Nose	A2-8
Chuck Size	254 mm (10 in)
Bar Capacity	76 mm (3.0 in)
X Axis Travel	240 mm (9.4 in)
Z Axis Travel	610 mm (24.0 in)
Turret Type	VDI 40, 12-station
Tool Capacity	12 stations (driven tools optional)
Rapid Traverse Rate	24 m/min (945 ipm) X, 24 m/min (945 ipm) Z
Guideway Type	Box guideways, X and Z
Machine Weight	5,500 kg (12,125 lb)
CNC Control	MSC-501/MAPPS IV (Mitsubishi-based)
650 Mm	25.6 in.
2158 Mm	85 in.
185 Mm	7.3 in.
345 Mm	13.6 in.
2000 Mm	78.7 in.
995 Mm	39.2 in.
958 Mm	37.7 in.

Specifications sourced from us.dmgmori.com — verified 2026-03-28

Strengths & Limitations

Strengths

Box guideways on both axes deliver surface finish quality and vibration damping that linear-guide machines from the same era cannot match
610 Nm spindle torque provides excellent cutting authority for interrupted cuts and heavy roughing in steel and stainless
Legendary build quality and service life with many machines running 15+ years on original spindle bearings with proper maintenance
76 mm bar capacity handles common production bar stock sizes and exceeds many competitors from the same generation
Used prices of 5,000-0,000 make the SL-403 one of the best rigidity-per-dollar values on the used lathe market
Parts availability remains good through DMG Mori service and aftermarket suppliers despite the model being discontinued

Limitations

No longer in production so only available as used machines with varying hours, condition, and remaining service life
Older MSC-500/501 controls lack the touchscreen interfaces and connectivity of modern CELOS or FANUC systems
No Y-axis option limits milling capability to C-axis indexed positions only, which may require second-operation work for complex milled features
4,000 RPM max spindle speed limits surface footage for high-speed aluminum and brass turning
Finding qualified DMG Mori technicians for older Mori Seiki control systems can be challenging in some regions

Best For

Job shops looking for a high-quality used lathe that delivers premium build quality at entry-level pricing Production shops needing a reliable workhorse for steel and stainless turning where rigidity and surface finish matter more than bells and whistles Training facilities wanting a solid, proven CNC lathe platform for student instruction at lower acquisition cost Shops with limited budgets that want box guideway quality without paying new-machine prices Second or third machines in growing shops that need capacity now without the lead time and cost of a new machine order

Frequently Asked Questions

01 What does a used SL-403 cost?

Used SL-403 machines from 2003-2015 typically trade between 5,000 and 0,000. Lower-hour machines from 2010-2015 with MAPPS IV controls command the top end. High-hour machines from the early 2000s can be found under 0,000.

02 What replaced the SL-403?

The NLX 2500 is the closest current-production equivalent. The NLX 2500 offers similar turning capacity with modern BMT turret technology, CELOS control, thermal compensation, and larger bar capacity. However, it costs 50,000+ new versus 5-80K for a used SL-403.

03 Are parts still available for the SL-403?

Yes. DMG Mori service departments still support the SL-403 platform. Aftermarket suppliers also stock common wear items like spindle bearings, turret components, chuck cylinders, and control boards. Availability is better than most discontinued machines from the same era.

04 SL-403 vs buying a new Haas ST-20?

A low-hour SL-403 at 0-60K delivers better build quality, box guideways, and surface finish than a new Haas ST-20 at similar pricing. The Haas wins on modern control features, warranty, and new-machine support. Choose the SL-403 for cutting performance; the Haas for ease of support.

05 What should I look for when buying a used SL-403?

Check spindle runout (under 0.005 mm is good), guideway wear patterns, turret indexing accuracy, hydraulic system condition, and control board availability. Request spindle hour readings if available. Machines from 2008-2015 with MAPPS IV controls are the best balance of capability and remaining life.