GF Machining Solutions Vertical Machining Centers

GF Mikron MILL S 500

$250,000 - $350,000 Updated 2025-03-15

Key Specifications

X Travel

500 mm (19.7 in)

Y Travel

450 mm (17.7 in)

Z Travel

350 mm (13.8 in)

Max Spindle

42,000 RPM

Spindle Taper

HSK-E40

Tool Capacity

30 tools (60 optional)

Overview

The GF Mikron MILL S 500 is one of the benchmark machines in the high-speed milling world, and for good reason. Built on GF Machining Solutions' polymer granite base with a 42,000 RPM Step-Tec spindle in HSK-E40, this machine was designed from the ground up for speed-class mold finishing, electrode machining, and precision component production. The 500 x 450 x 350 mm (19.7 x 17.7 x 13.8 in) work envelope handles the vast majority of mold insert and small die work.

The S in the name stands for Speed, and GF means it. The 42,000 RPM spindle lets you run micro-diameter cutters at optimal SFM without compromising tool life, and the machine's acceleration and jerk rates are tuned for the kind of tight-radius contouring that defines modern mold finishing. Rapid traverse is 61 m/min (2,402 ipm), which keeps non-cutting time to a minimum on complex multi-feature parts. The polymer granite base absorbs high-frequency vibrations that would destroy surface finish on a conventional cast iron platform.

GF specs the MILL S 500 with the Heidenhain TNC 7 control on current models, which delivers advanced look-ahead, Dynamic Precision features, and a modern touchscreen interface. The 30/60 pocket tool magazine handles typical mold shop tooling requirements, and System 3R automation integration is available for pallet-based lights-out production. The integrated thermal management system — which actively monitors and compensates for spindle, structure, and ambient temperature variations — is what allows the machine to hold ±4 micron accuracy over 24-hour cycles.

Surface finishes of Ra 0.1 micron are achievable on hardened steel, which puts the MILL S 500 in the same conversation as dedicated ultra-precision machines costing significantly more. The machine competes directly with the Makino F5, Roku-Roku RMX-5, and Yasda YBM Vi40, though each takes a slightly different approach to achieving similar end results.

New MILL S 500 machines price between $250,000 and $350,000 depending on configuration. Used machines from 2015-2020 vintages trade between $100,000 and $200,000. The MILL S 500 has been in production in various forms for over two decades, and the current generation represents the refinement of a proven platform.

Full Specifications

Parameter	Value
X-Axis Travel	500 mm (19.7 in)
Y-Axis Travel	450 mm (17.7 in)
Z-Axis Travel	350 mm (13.8 in)
Max Spindle Speed	42,000 RPM
Spindle Taper	HSK-E40
Spindle Motor Power	13.5 kW (18 hp)
Spindle Torque	8.8 Nm (6.5 ft-lb)
Tool Capacity	30 tools (60 optional)
Table Size	600 x 500 mm (23.6 x 19.7 in)
Max Work Weight	300 kg (661 lb)
Rapid Traverse Rate	61 m/min (2,402 ipm)
Feed Rate	30 m/min (1,181 ipm)
Surface Finish	Ra 0.1 µm achievable
Thermal Accuracy	±4 µm over 24-hour cycle
CNC Control	Heidenhain TNC 7
Machine Weight	6,200 kg (13,669 lb)
Machine Base	Polymer granite

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

Strengths & Limitations

Strengths

42,000 RPM Step-Tec spindle enables optimal cutting speeds on micro-diameter tools, delivering Ra 0.1 µm surface finishes on hardened steel
Polymer granite base provides 6-8x better vibration damping than cast iron, critical for maintaining finish quality at high spindle speeds
Integrated thermal management system holds ±4 µm accuracy over 24-hour unattended machining cycles
61 m/min rapid traverse minimizes non-cutting time on complex multi-feature mold work
Heidenhain TNC 7 control with advanced look-ahead and Dynamic Precision is one of the best HSM control platforms available
System 3R automation compatibility enables straightforward pallet-based lights-out production

Limitations

HSK-E40 taper and 8.8 Nm torque limit roughing capability — this is fundamentally a finishing and semi-finishing machine
500 x 450 mm X/Y travel restricts workpiece size; shops needing more envelope should consider the MILL S 600 or S 800
Premium pricing puts the MILL S 500 at 2-3x the cost of a comparable-envelope conventional VMC
GF Machining Solutions' North American service network is thinner than Haas, Mazak, or DMG Mori
Maximum workpiece weight of 300 kg limits the machine to smaller precision parts — no room for heavy die blocks

Best For

Precision mold finishing where Ra 0.1 µm surface quality eliminates or reduces hand polishing Graphite and copper electrode production for sinker EDM operations Medical device component machining requiring tight tolerances and excellent surface finish Watch and luxury goods manufacturing where Swiss precision and micro-detail are essential High-mix mold shops running lights-out with System 3R pallet automation Hardened steel machining (up to 62 HRC) with small-diameter carbide and CBN tooling

Frequently Asked Questions

01 What does a new GF Mikron MILL S 500 cost?

New MILL S 500 machines typically price between $250,000 and $350,000 depending on configuration. Key price drivers include control choice, tool magazine size (30 vs 60), probing packages, and System 3R automation. Used machines from 2015-2020 trade between $100,000 and $200,000. Step-Tec spindle rebuilds run $15,000-$25,000 on older units.

02 How does the MILL S 500 compare to the Makino F5?

The Makino F5 uses a 20,000 RPM HSK-A63 spindle with higher torque (120 Nm), making it more capable for combined roughing and finishing. The MILL S 500 counters with 42,000 RPM and superior vibration damping, giving it an edge on fine finishing and micro-tool applications. The F5 is more versatile; the S 500 is more specialized for speed-class finishing. The Makino is typically priced 10-15% higher.

03 What's the difference between the MILL S 500 and MILL P 500?

The S 500 prioritizes speed with a 42,000 RPM HSK-E40 spindle optimized for finishing. The P 500 (Performance) uses a similar 42,000 RPM HSK-E40 spindle but adds enhanced thermal stability features and is tuned for tighter accuracy over longer machining cycles. The P 500 targets shops doing the most demanding precision work where every micron matters.

04 Can the MILL S 500 handle roughing?

Light roughing yes, heavy roughing no. With 8.8 Nm of torque and an HSK-E40 taper, the machine is optimized for high-speed finishing and semi-finishing with small-diameter tools. Shops that need serious roughing capability on the same platform should look at the MILL E or P 900 series with HSK-A63 spindles and significantly higher torque.

05 What Step-Tec spindle options are available?

The standard spindle is the 42,000 RPM HSK-E40 unit. A 30,000 RPM HSK-E40 option is available for shops that want a broader speed range with slightly more torque. Step-Tec spindles are manufactured in-house by GF Machining Solutions and are known for excellent longevity when properly maintained — 10,000+ hours between rebuilds is common.

06 How long does a Step-Tec spindle last?

Step-Tec spindles typically last 8,000-15,000 hours between rebuilds, depending on application severity and maintenance practices. GF recommends regular spindle warmup cycles and proper coolant management. Rebuild cost runs $15,000-$25,000 through GF's service centers. The spindles are designed for easy field replacement — a trained technician can swap one in under a day.