# Rotary tables

Machining rotary-table indexing, simultaneous control, angular accuracy, torque and workpiece-support limits.

Reviewed: 2026-11-02

Tags: tooling, workholding, rotary-tables, indexing

Haas's **HRT160** lists **203 N·m continuous spindle torque** and **136 N·m brake torque at 100 psi (6.9 bar)**. Maximum platter weight is **40.8 kg supported** or **20.4 kg unsupported**. Check whether the operation uses a stationary locked table or coordinated motion, and check overhang and load moment separately. [Haas HRT160 load specifications](https://www.haascnc.com/machines/rotaries-indexers/rotary-tables/models/hrt160.html).

Use [Choosing workholding](../workholding-and-fixtures.md) to compare location, support and restraint across fixture types.

## Purpose and motion

Haas offers rotary axes for indexing and coordinated machining. The table must support the loaded fixture throughout the intended motion. [Haas rotary introduction](https://www.haascnc.com/service/online-operator-s-manuals/rotary-tailstock---operator-s-manual-supplement/rotary---introduction.html)

| Use | Rotary behavior | Capability that remains separate |
| --- | --- | --- |
| Index and cut | Move to an angle, then machine at that position | Holding stiffness and load capacity |
| Simultaneous machining | Rotate in coordination with other machine axes | Compatible CNC, drives and interpolation |
| Manual angular positioning | Position using a handwheel and scale | Scale graduation versus achieved accuracy |
| Tilting-rotary arrangement | Add another angular axis | Its own travel, torque and collision envelope |

Verify CNC interpolation capability separately from motorization. A brake holds position while engaged.

## Drives and control interfaces

Sherline's 4-inch table family illustrates a worm-driven design: its 72:1 ratio produces 5° of platter rotation per handwheel revolution, with 0.1° handwheel graduations. The family includes manual, stepper-ready, motor-equipped and separately programmable-indexer versions. A motor mount does not itself include a motor, drive or integrated machine control. [Sherline rotary tables](https://www.sherline.com/rotary-tables/)

Haas's introduction calls a head plus separate Servo Control a semi-fourth-axis system. It separately lists true simultaneous fourth/fifth-axis control through the CNC without that Servo Control unit. These are Haas interface descriptions; a generic electrical connection or spare machine signal does not establish coordinated interpolation. [Haas control arrangements](https://www.haascnc.com/service/online-operator-s-manuals/rotary-tailstock---operator-s-manual-supplement/rotary---introduction.html)

Kitagawa's RK201 is a roller-gear/cam-driven example. Its page distinguishes mechanical pneumatic clamping from holding through motor torque, so drive type and stationary locking method are separate specifications. [Kitagawa RK201](https://www.kitagawa.com/en/mtools/nct/rk201.html)

## Accuracy, repeatability and backlash

Haas's HRT160 product specification lists **±15 arc-seconds indexing accuracy**, **10 arc-seconds repeatability**, **30 arc-seconds backlash** and **0.013 mm maximum runout**. These are distinct properties of that model; they do not describe the same error or establish finished-part tolerance. [Haas HRT160 specifications](https://www.haascnc.com/machines/rotaries-indexers/rotary-tables/models/hrt160.html)

**Interpretation:** angular accuracy concerns closeness to the commanded position; repeatability concerns returning to a position under the measurement conditions. Backlash concerns lost motion on reversal. Runout describes geometric variation rather than angular positioning. Display resolution, gear ratio and a handwheel graduation supply none of those quantities automatically.

An original small-angle comparison converts 15 arc-seconds to `15 / 3,600 = 0.0041667°`, or approximately `0.000072722 rad`. At a hypothetical 100 mm feature radius, the corresponding tangential displacement is `100 × 0.000072722 = 0.007272 mm`, approximately **7.27 µm**. This uses the cited angular magnitude only; mounting, axis location and fixture errors are additional. [Angular magnitude: HRT160](https://www.haascnc.com/machines/rotaries-indexers/rotary-tables/models/hrt160.html)

## Holding torque, drive torque and supported mass

The HRT160 page separately lists **203 N·m continuous spindle torque** and **136 N·m brake torque at 100 psi/6.9 bar**. Maximum platter weights are **40.8 kg with support** and **20.4 kg unsupported**. These values belong to the specified arrangement; supported mass, cutting torque and overturning moment are not interchangeable ratings. [Haas HRT160 load specifications](https://www.haascnc.com/machines/rotaries-indexers/rotary-tables/models/hrt160.html)

For the RK201, Kitagawa lists **340 N·m pneumatic clamping torque at 0.5 MPa**. It separately gives **108 N·m maximum continuous motor holding torque** and **240 N·m instantaneous holding torque**, explicitly scoped to its QUINTE controller; fourth-axis configurations differ. Its advertised **0.31 s for 90° indexing** excludes pneumatic clamping and uses servo holding. That timing is not a complete clamp–move–settle machining cycle. [Kitagawa RK201 specifications and notes](https://www.kitagawa.com/en/mtools/nct/rk201.html)

Check overhang, bearing moments and inertia in addition to payload and torque. Include the attached fixture and its restraint.

## Worked example: seven equal divisions

**Original ideal arithmetic using the cited 72:1 ratio:** seven equally spaced positions require `360 / 7 = 51.428571…°` per division. On that worm ratio, the corresponding handwheel motion is `72 / 7 = 10.285714…` revolutions per division. [Ratio context: Sherline](https://www.sherline.com/rotary-tables/)

Ten whole turns alone would move the table 50°, leaving 1.428571…° of the division. This calculation explains the distinction between a reduction ratio and a practicable indexing method; it does not claim that the handwheel's graduations resolve every fractional division exactly. A controller's numeric input resolution likewise does not guarantee equivalent positioning accuracy.

## Coverage and source dates

No technical issue dates were established for the cited product pages or Haas online introduction. Search timestamps and website copyright years are not technical editions. This article covers machining workholding tables, not transfer-machine indexing stations or drilling-rig rotary tables.

The sources do not establish universal positioning accuracy, speed, payload, cutting torque or controller compatibility. Machine travel, center height, mounting, fixture envelope, support, utilities and control options remain assembly-specific. Catalog features do not establish a shop's installed fourth/fifth-axis capability or approved machining setup.

## Related reference

[Workholding and fixture references](index.md)