EMAG EMAG HG 204
Key Specifications
Max Workpiece ⌀
max workpiece length
x axis travel
z axis travel
spindle config option 1
spindle config option 2
Overview
The EMAG HG 204 is a multi-spindle CNC external cylindrical grinder designed for complex production grinding operations on shaft and chucked components up to 200 mm in diameter and 400 mm in length. What sets the HG 204 apart from the base HG 2 is its modular B-axis turret system that accommodates multiple grinding spindles, enabling multi-operation grinding in a single clamping without re-fixturing — a critical capability for components requiring OD grinding, ID grinding, and angular grinding in a single cycle.
The machine offers three principal spindle configurations: a B-axis with two external grinding spindles accepting wheels up to 500 mm diameter; a B-axis with one external spindle (500 mm max) plus two internal grinding spindles for combined OD/ID work; or a B-axis with three external spindles accepting wheels up to 400 mm diameter for multi-diameter plunge grinding. This configurability makes the HG 204 one of the most versatile production grinders in EMAG’s portfolio.
With 360 mm of X-axis travel and 1,000 mm of Z-axis travel, the HG 204 provides the work envelope for complex multi-step grinding operations. Absolute measuring systems with linear glass scales in all axes ensure positioning accuracy is maintained across the full travel range and throughout extended production runs. The machine supports both motor spindle and belt-driven spindle work headstock configurations, and the NC tailstock with large stroke accommodates varying workpiece lengths.
The HG 204 includes in-process measuring capability, automatic wheel balancing, and crash/contact recognition systems that ensure consistent quality and protect the machine during production. An automated loading hatch facilitates integration with external material handling systems for automated production cells. The machine accepts both corundum and CBN grinding wheels across all spindle positions.
New EMAG HG 204 machines typically price between $400,000 and $700,000 depending on the number of spindles, automation level, and optional features.
Full Specifications
| Parameter | Value |
|---|---|
| Max Workpiece Diameter | 200 mm (7.9 in) |
| Max Workpiece Length | 400 mm (15.7 in) |
| X Axis Travel | mmin |
| Z Axis Travel | mmin |
| Spindle Config Option 1 | B-axis with 2 external spindles, 500 mm max wheel diameter |
| Spindle Config Option 2 | B-axis with 1 external (500 mm) + 2 internal grinding spindles |
| Spindle Config Option 3 | B-axis with 3 external spindles, 400 mm max wheel diameter |
| Work Headstock Options | Motor spindle or belt-driven spindle |
| Measuring System | Absolute glass scales in all axes |
| In Process Gauging | Available for OD and shoulder measurement |
| Wheel Balancing | Automatic balancing unit |
| Crash Recognition | Contact and crash detection system |
| Grinding Media | Corundum or CBN |
| Tailstock | NC-controlled with large stroke |
| Loading | Automated loading hatch for external material handling |
| CNC Control | CNC (FANUC or Siemens) |
| Workpiece Dia Max | mmin |
| Workpiece Length Max | mmin |
Specifications sourced from emag.com — verified 2026-03-28
Strengths & Limitations
Strengths
- Modular B-axis turret system with up to three grinding spindles enables multi-operation grinding (OD, ID, angular) in a single clamping without re-fixturing
- Three spindle configuration options provide maximum flexibility to match the machine to specific application requirements and part geometries
- In-process measuring, automatic wheel balancing, and crash recognition ensure consistent quality and machine protection during unattended production
- Absolute glass scale measuring systems in all axes maintain positioning accuracy across extended production runs regardless of thermal drift
- Combined OD and ID grinding capability with the dual-type spindle configuration eliminates the need for separate machines for bore and cylindrical work
- Automated loading hatch facilitates integration with gantry loaders, robots, or conveyor systems for automated production cells
Limitations
- Premium pricing of $400K-$700K reflects the multi-spindle complexity requiring high-volume production of complex parts to justify the investment
- Multiple spindle configurations add setup complexity compared to single-spindle grinders requiring higher operator skill levels
- 200 mm maximum workpiece diameter limits the machine to small-to-medium components as larger work requires the HG 208 platform
- Lead times for customized multi-spindle configurations can extend to 6-9 months from order to delivery
Best For
Frequently Asked Questions
01
Three configurations: (1) B-axis with two external grinding spindles accepting wheels up to 500 mm diameter; (2) B-axis with one external spindle (500 mm max) plus two internal grinding spindles for combined OD/ID work; (3) B-axis with three external spindles accepting wheels up to 400 mm.
02
The HG 2 is a single-spindle external cylindrical grinder, while the HG 204 adds a B-axis turret with multiple grinding spindles (up to three). The HG 204 can perform multiple grinding operations in a single clamping, eliminating re-fixturing.
03
Yes. The HG 204 can be equipped with an in-process measuring attachment for real-time diameter and shoulder position monitoring during grinding. This closed-loop measurement ensures consistent part dimensions without stopping the machine for manual gauging.
04
Yes, across all spindle positions. The machine supports both conventional corundum and CBN grinding wheels. CBN is typically chosen for production grinding of hardened steel components where its superior wear resistance translates to longer wheel life and faster cycle times.
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