Blohm PLANOMAT HP 412
Key Specifications
table working area
max workpiece weight
longitudinal travel x
cross travel y
vertical travel z
grinding spindle power
Overview
The Blohm PLANOMAT HP 412 is a high-precision CNC surface grinding machine in Blohm's PLANOMAT HP (High Precision) series, offering a 400 × 1,200 mm magnetic chuck working area on a platform engineered specifically for the flatness, parallelism, and surface finish tolerances demanded by precision toolmaking, die and mold, gauge manufacturing, and high-accuracy component production. The HP designation distinguishes the PLANOMAT HP series from Blohm's production-oriented surface grinders — the HP line prioritizes geometric accuracy and thermal stability over maximum material removal rate, targeting shops and toolrooms where a precision surface grinder is the final arbiter of workpiece precision.
The PLANOMAT HP 412's machine architecture is built for geometric accuracy. The machine base is cast from polymer concrete for vibration damping and thermal mass, the wheelhead spindle uses precision hydrostatic or roller bearings depending on configuration, and the guideway system is designed to minimize Abbe offset errors across the full table travel. These design choices directly translate into the flatness and parallelism tolerances achievable: the PLANOMAT HP 412 is capable of grinding flat surfaces to flatness values below 1 µm across the full table area under appropriate environmental and thermal conditions.
The grinding spindle on the PLANOMAT HP 412 provides 15–22 kW of power with peripheral wheel speeds to 63 m/s — adequate for precision surface grinding of hardened tool steels, carbide plates, and precision gauge blanks. The Siemens 840D sl control manages X, Y, and Z axes with micron-level resolution, and Blohm's grinding-specific HMI provides straightforward programming of grinding cycles, dressing sequences, and multi-pass strategies for achieving fine surface finishes. Surface finish capability reaches Ra < 0.05 µm with optimized parameters and appropriate wheel selection.
The PLANOMAT HP 412 is specified by precision toolmakers, gauge manufacturers, and high-accuracy component producers who need a surface grinder with demonstrably superior geometric accuracy over production-line grinders. New pricing typically falls in the $280,000–$420,000 range — a premium over standard surface grinders of comparable table size, reflecting the precision-optimized design, tighter machine build tolerances, and Blohm's positioning in the high-accuracy surface grinding segment alongside competitors such as Mitsui Seiki and Jones & Shipman.
Full Specifications
| Parameter | Value |
|---|---|
| Table Working Area | 400 × 1,200 mm (15.7 × 47.2 in) |
| Max Workpiece Weight | 600 kg (1,323 lb) |
| Longitudinal Travel X | 1,350 mm (53.1 in) |
| Cross Travel Y | 500 mm (19.7 in) |
| Vertical Travel Z | 450 mm (17.7 in) |
| Grinding Spindle Power | 15 - 22 kW (20.1 - 29.5 HP) |
| Max Wheel Peripheral Speed | 63 m/s |
| Max Grinding Wheel Diameter | 500 mm (19.7 in) |
| Max Grinding Wheel Width | 80 mm (3.15 in) |
| Flatness Capability | < 1 µm (controlled environment) |
| Surface Finish Capability | Ra < 0.05 µm |
| Rapid Traverse Longitudinal | 20,000 mm/min (787 ipm) |
| Machine Base | Polymer concrete for vibration damping |
| CNC Control | Siemens 840D sl with Blohm PLANOMAT HP interface |
Strengths & Limitations
Strengths
- High-precision-optimized machine architecture with polymer concrete base, precision guideway design, and tight assembly tolerances enables flatness below 1 µm — exceeding what production surface grinders can achieve
- Surface finish capability to Ra < 0.05 µm satisfies the most demanding gauge, tooling, and precision component requirements
- 400 × 1,200 mm table area handles long workpieces — guideways, mold inserts, and precision plates — in a single setup without re-fixturing
- Siemens 840D sl control with micron-resolution axis positioning enables multi-pass grinding strategies and fine spark-out passes that precision surface grinding demands
- Polymer concrete base provides excellent thermal mass and vibration damping, protecting achievable flatness from shop floor vibration and thermal cycling during production shifts
Limitations
- At $280,000–$420,000, the PLANOMAT HP 412 commands a premium over standard CNC surface grinders of comparable table size — justified by precision capability but not for shops where geometric tolerances are 5 µm or looser
- The 22 kW maximum spindle power and 63 m/s wheel speed prioritize precision over high material removal rate — the PLANOMAT HP 412 is not optimized for high-production stock removal
- Achieving the machine's flatness capability below 1 µm requires a temperature-controlled environment, proper machine thermal stabilization, and experienced grinding technique — typical shop floor conditions will yield more modest results
Best For
Frequently Asked Questions
01
The PROFIMAT series (408, 412, MT variants) is Blohm's production-oriented surface and profile grinding line, optimized for multi-technology capability (pendulum + creep-feed), high material removal rates, and heavier workpieces. The PLANOMAT HP series prioritizes geometric accuracy and surface finish — the machine build, guideway design, and spindle specification are optimized for flatness and parallelism rather than MRR or profile flexibility. Choose the PLANOMAT HP when the surface grinder is the precision arbiter in your process; choose the PROFIMAT for production volume and profile grinding.
02
Under controlled temperature conditions (20°C ± 1°C, thermally stabilized machine, appropriate spark-out passes), the PLANOMAT HP 412 is capable of grinding flatness below 1 µm across the full 400 × 1,200 mm table area. In a typical shop environment without temperature control, realistic expectations are 2–5 µm flatness for standard production work — still significantly better than most production surface grinders. For best results, Blohm recommends temperature-controlled environments and machine warm-up protocols before precision work.
03
The PLANOMAT HP 412 grinds the full range of ferrous materials on a magnetic chuck: hardened tool steels (D2, H13, M2), P20 and H13 mold steels, bearing steels, stainless steels, and carburized case-hardened steels. With a vacuum chuck or mechanical fixture, non-ferrous materials including carbide plates, ceramics, and glass can also be ground. The precision spindle is particularly valued for grinding fine-grain tool steels and carbide where surface finish directly affects EDM electrode quality or die wear performance.
04
The PLANOMAT HP 412 can perform limited profile grinding with a dressed profile wheel — single-rib profiles, angles, and simple forms are possible with standard wheel dressing. However, the PLANOMAT HP series is not designed for deep creep-feed profile grinding cycles. For complex, deep profiles such as turbine root forms or gear tooth profiles, the PROFIMAT series with its higher spindle power and rigid creep-feed capability is the appropriate choice.
05
The PLANOMAT HP 412 competes with the Mitsui Seiki MSG-412H, Jones & Shipman Ultramat series, and precision Okuma GP surface grinders in the high-accuracy CNC surface grinding segment. Blohm's strength is the combination of the polymer concrete base, precision guideway design, and the backing of United Grinding's service and support network. The machine is widely respected in the toolmaking and precision manufacturing community as a benchmark-class surface grinder for shops that require documented flatness and surface finish capability.
Videos
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Community Discussions
Maintenance and service — Alarm 412 in fanuc 3M - CNCzone
Community discussion — Manuals and Useful Documentation List - CNCzone
Troubleshooting and problem-solving — Need Help! FANUC 18i-m Alarm Message 443 - Fan failure - CNCzone
Maintenance and service — Need Help! 410 and 412 alarms on 0m fanuc - CNCzone
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