Table-Type Horizontal Boring Mills: Capacity & Automation

ELK GROVE VILLAGE, IL. — November 12, 2026 

Buying a large boring mill usually comes down to two limits: how big a part the machine can take in the floor space you have, and how much of each shift the spindle spends waiting on setups.

A table-type horizontal boring mill handles both. It carries the part on a rotary table under a horizontal spindle that extends into deep bores. It covers most large prismatic parts, such as housings, gearbox cases and pump bodies, in less floor space than a floor-type machine. Add an automatic two-pallet changer (APC) and your set-up time is significantly reduced.

This guide covers how to size one, what the compact design buys you, and where a pallet changer pays off, using published specs for Shibaura Machine’s BTD series. Still deciding whether a boring mill is the right machine at all? Start with our comparison of boring mills, double column machining centers and vertical turning lathes. Learn More.

What is a table-type horizontal boring mill?

A table-type horizontal boring mill (HBM) is a boring and milling machine with a horizontal spindle and a rotary table that carries the part. Three linear axes, X, Y and Z, position the spindle relative to the part. The W-axis extends the spindle or quill to reach into deep bores. The B-axis rotates the table to present each face to the spindle.

That combination is why HBMs are the standard machine for housings, gearbox cases, pump and valve bodies, frames and other large prismatic parts. Most of those parts need accurate bores on more than one face, and the rotary table reaches them without re-clamping.

Table-type vs floor-type: which do you need?

The difference is where the part sits and what moves.

Pick table-type when your largest regular part, with its fixture, fits within a table rating and clears the column as the table rotates. Pick floor-type when parts outgrow every table, or when you need X travel far beyond what a table machine offers.

How much capacity do you need?

Start with the part, not the machine. Five checks cover most decisions.

1. Weight with the fixture. Add the part, fixture and any riser or pallet, and compare the total with the table rating. If you plan to use a pallet changer, compare it with the per-pallet rating.
2. Swing, not just length and width. When the table rotates, the part’s corners sweep a circle. The largest corner-to-corner dimension has to clear the column at every index position.
3. Travel to every feature. Check X, Y and Z travel against every feature, plus tool length. Features near the top and edges of a large part are where envelopes run out.
4. Reach for the deepest bore. W-axis travel sets how deep you can bore without long, flexible tooling. Bores that must line up across opposite faces need enough reach or a plan to bore from both sides.
5. Spindle size and speed. A larger spindle offers a longer extension.

Then leave headroom. A boring mill typically stays on the floor for decades, and the next job you quote may be the next size up.

The BTD series by the numbers

Shibaura’s BTD models span three table sizes. All three use a FANUC 31i-B Plus control and include a rotary milling function, which machines cylindrical and end surfaces with continuous B-axis indexing instead of a separate NC rotary table.

Source: Shibaura Machine spec pages, October 2026. Some specifications change when the pallet changer is selected, so confirm final numbers for your configuration.

Need more? The BTH-150.R35 carries a 5.9-inch (150 mm) spindle, 157 inches of X travel (236 inches optional) and a 78 x 137 inch table rated for up to 55,000 lb.

Why compact design matters

Floor space in an existing building is expensive to add and slow to approve. Shibaura describes the BTD line as compact in design but rigid enough to replace existing equipment. In practice, that means you can upgrade an aging boring mill without redesigning the bay around it.

Rigidity where it counts. The BTD-130S.R22 uses a double pinion drive on the B-axis for stable table indexing. BTD models list scale feedback on the X, Y and Z axes and on the B rotary axis for positioning accuracy.

Coolant through the spindle. The BTD and BTH series come standard with Big Plus tooling and coolant through the spindle.

Manual and CNC work together. A portable handwheel unit covers the X, Y, Z, W and B axes, so operators can set up and touch off without walking back to the control.

Can you automate a large boring mill?

Yes. On a boring mill, the first step is usually a two-pallet APC. While the machine cuts the part on one pallet, an operator fixtures and indicates the next part on the other. When the cut finishes, the pallets swap and the spindle starts again in minutes instead of hours.

The gain depends on your setup time. If fixturing a large part takes two hours and the cut takes three, a pallet changer moves most of those two hours off the spindle on every part. Without one, the spindle waits.

Plan around these points:

• An optional Renishaw probe measures the part on the machine, and a tool-setting probe measures tool length and sets offsets. Both cut the manual checks between operations.
• Tool capacity. ATC tool magazine pockets decide how many jobs can run before someone has to swap tools by hand.
• Connecting the machine to an IIoT platform such as Shibaura’s machiNetCloud shows how much of each shift the spindle actually cuts, which is how you prove the pallet changer is paying off.

See the BTD series

Compare models on the BTD series page, or send a part drawing and we’ll recommend a model and configuration. Shibaura Machine keeps an extensive machine inventory in North America for quick delivery.

Request a quote or contact the Machine Tool Sales team at (888) 593-1616 or MT-Sales@shibaura-machine.com.

Frequently asked questions

What is a table-type horizontal boring mill?

A table-type horizontal boring mill is a boring and milling machine with a horizontal spindle that extends (the W-axis) and a rotary table that carries the part. The table indexes to present each face, so housings, bodies and frames can be bored and milled on several sides in one setup.

What is the difference between table-type and floor-type horizontal boring mills?

On a table-type HBM, the part rides on a rotary table, which keeps the machine compact and suits parts up to the table’s load rating. On a floor-type HBM, the column travels along a floor runway while the part sits on floor plates, which suits parts too large or heavy for any table.

How much table load capacity do I need?

Add the part, fixture and any riser, then compare that total with the table rating, or with the per-pallet rating if you use a pallet changer. Leave headroom for larger future work. For reference, Shibaura’s BTD tables are rated from 8,800 lb on the BTD-200QS to 26,400 lb standard on the BTD-130S.R22.

Can you automate a horizontal boring mill?

Yes. The most common step is a two-pallet automatic pallet changer, which lets an operator fixture the next part while the machine cuts the current one. Probing and a larger tool magazine add more unattended time. On Shibaura BTD models the APC is an option, and per-pallet ratings are usually lower than table ratings.

Which BTD model fits my part?

Match your heaviest part plus fixture to the table or pallet rating, and its corner-to-corner size to the table and travels. The BTD-200QS suits parts up to 8,800 lb on a 39 x 47 inch table, the BTD-110S.R16 up to 13,860 lb on 55 x 63 inches, and the BTD-130S.R22 up to 26,400 lb on 71 x 87 inches.

Contact us at at (888) 593-1616 or mt-sales@shibaura-machine.com.