VMC855 Vertical Machining Center: Built for Medium-to-Heavy Workpieces
If your shop regularly cuts steel housings, mold inserts, or automotive components that push a 1,000 x 550 mm table to its limit, a light-duty VMC will show it quickly. The VMC855 vertical machining center from BONANZA is a different class of machine. It carries a 5,300 kg structure, 800/550/550 mm X/Y/Z travels, and an 8,000 rpm BT40 belt spindle behind a 24-tool disc ATC. That combination is aimed at one thing: holding accuracy while you take heavier cuts than a 650-class machine would tolerate.
This article walks through the actual specifications, what they mean on the shop floor, and which options matter for batch production versus one-off mold work.
VMC855 Specifications at a Glance
| Parameter | VMC855 |
|---|---|
| X / Y / Z travel | 800 / 550 / 550 mm |
| Spindle taper | BT40 |
| Spindle speed | 8,000 rpm (belt-driven) |
| Tool magazine | 24-tool disc ATC |
| Machine weight | 5,300 kg |
| Guide system | Precision linear guides (3-axis) |
| Typical workpieces | Medium-to-heavy parts, molds, automotive components |
| Optional extras | Through-spindle coolant, chip conveyor, smart networking |
Why the 5,300 kg Structure Matters
Machine weight is not a marketing number. Every kilogram of cast iron in the base and column adds damping, and damping is what keeps tool chatter away when you are pushing a 50 mm end mill through EN8 steel. The VMC855’s rigid structure, combined with precision linear guides on all three axes, gives you a stable platform for both roughing passes and the finishing pass that follows them.
For shops that have run lighter machines, the difference shows up in surface finish consistency and in tool life. A rigid machine lets the insert do the cutting instead of the machine flexing and vibrating the edge off the insert.
The Spindle and Tool Magazine: 8,000 rpm BT40 with a 24-Tool Disc ATC
The 8,000 rpm BT40 belt spindle is a practical choice for this class. You get enough speed for aluminum and alloy machining, plus the torque delivery of a belt drive for steel work. Tool changes come from a 24-tool disc magazine, which covers most job-shop tooling lists: face mills, end mills, drills, taps, and boring bars can all live in the magazine without manual swaps between operations.
For high-mix work, that means you can set a job up in the morning, load the tooling list once, and let the machine run through the sequence. The 24-station capacity is enough for the majority of medium-complexity parts without forcing you into a larger, more expensive machine.
Where the VMC855 Fits
BONANZA positions the VMC855 for four application groups:
- Automotive parts – gearbox housings, brackets, and suspension components where batch repeatability counts.
- Mold making – inserts and cavity blocks that need stable cutting and good finish on the last pass.
- General machinery – pump bodies, valve blocks, and frames for custom equipment.
- Aerospace components – smaller structural parts and fittings where documented, repeatable processes matter.
If your work is consistently lighter, the VMC series lineup also includes the compact VMC650 for 3C and light alloy parts, and the 855D for a direct-drive alternative with the same travels. On the heavy end, the 1690 with its BT50 spindle handles large dies and fixtures up to 1,500 kg.
Options That Change How You Run It
Three optional extras are worth a serious look when quoting the VMC855:
- Through-spindle coolant – flushes chips out of deep holes and keeps the cutting zone cool on drilling and boring operations. Nearly essential for mold work.
- Chip conveyor – automated chip removal keeps the machine running unattended longer, which matters for batch production and lights-out shifts.
- Smart networking – production data collection and remote monitoring support the kind of process tracking that automotive and aerospace customers now expect from suppliers.
None of these change the base geometry of the machine. They let you match it to how you actually work: single parts with frequent setups, or batches that should run while the operator does something else.
Frequently Asked Questions
Can the VMC855 handle steel cutting?
Yes. The 5,300 kg rigid structure and belt-driven BT40 spindle are specified for medium-to-heavy steel and alloy machining. For very deep or interrupted cuts, add the through-spindle coolant option and choose tooling suited to the material.
What is the difference between the VMC855 and the 855D?
Both share the 800/550/550 mm travels and 8,000 rpm BT40 spindle. The 855D uses a direct-drive spindle configuration, while the VMC855 uses a belt drive. The right choice depends on your torque and speed profile; ask BONANZA for the comparison based on your part list.
Is the 24-tool magazine enough?
For most medium-complexity parts, yes. If your tooling list regularly exceeds 24 stations, BONANZA’s larger VMC models with extended magazines may be a better fit, and the sales team can walk you through the options.
Get the VMC855 Quoted for Your Work
Spec sheets only tell part of the story. If you are cutting medium-to-heavy parts and want to see how the VMC855 would fit your floor, send BONANZA your part drawings or a typical tooling list. You will get a machine recommendation, optional extras that actually apply to your work, and pricing for your configuration.
For the full range, browse the vertical machining centers collection or contact the BONANZA team directly through the website.