AT Series – Rotary Air Bearing Table

Air Bearing Rotary Tables

ABTech’s precision air bearing rotary tables address the metrology needs for different weights and part size. Built for the most demanding applications, every table provides ultra-smooth motion, sub-micron accuracy and absolute repeatability. Designed and manufactured in-house to extremely tight geometric tolerances, air bearings have no mechanical contacting parts to wear or create drag. This allows for decades of reliable maintenance-free motion.

ABTech’s AT models come standard with dual element filter/regulators and are commonly used as the core axis in equipment checking total indicator reading (TIR), roundness, flatness, squareness, perpendicularity, concentricity and parallelism measurements. They are ideal as stand-alone units for checking runout of turned parts, optical lens alignment, assembly applications, precision indexing, and light machining or grinding.

The heavy-duty HDRT tables complete the product family. They are a perfect solution for large part applications.

To speed part setup and increase productivity, the AT model tables come standard with our industry-best adjustable tilt and center (tip/tilt) work-tables. The tilt and center are optionally available on the HDRT models.

We understand metrology needs often require operating in harsher environments. We use the most durable hardened 440C stainless-steel air bearing. This affords forgiveness from minor accidental touch downs that may result from low air pressure, excessive loading, or operator error.

All rotary tables can be customized with a variety of options and accessories including motor drives, vacuum worktable (AT Series), high-resolution optical encoders, digital readout (DRO) displays, inspection-grade granite surface plates and gage stands.

If our standard tables don’t fit your application, our precision motion experts will work closely with you to configure a rotary motion solution that will meet your exact needs.

AT Series – Rotary Air Bearing Table
AT Series – Rotary Air Bearing Table
AT300 Rotary Air Bearing
AT300 Rotary Air Bearing
HDRT Series – Rotary Air Bearing Table
HDRT Series – Rotary Air Bearing Table
HDRT 3000
HDRT 3000

Features & Benefits

  • Accurate, Repeatable, Smooth Motion

    Manufactured with tight geometric tolerances, our standard air bearings deliver radial and axial error motion of <2.0 µ” (50.0 nanometers) and angular errors (coning) of 1.0 µ” per inch (25.0 nanometers/25mm). And custom configurations can deliver the ultimate in accuracy with radial and axial error motion of as little as 1.0 µ” (25.0 nanometers) and angular errors (coning) of 0.5 µ” per inch (12.5 nanometers/25mm). Air bearings provide significant advantages over mechanical bearings or other approaches to precision worktables. They have no mechanical contacting parts to wear, or create drag, air bearings are close to frictionless, providing ultra-smooth, repeatable and maintenance-free motion.

  • Superior Durability

    Metrology is no longer relegated to the quality control lab. To maximize productivity, we know many applications require integrating measurement devices within the production and assembly processes. This means being exposed to harsher environments, ABTech uses hardened 440C stainless steel components – so you’ll experience many years of service and investment longevity.

  • Configuration Flexibility to Meet Your Specific Needs

    Part of our “Pride in Precision” philosophy means providing you with the precise solution needed. We don’t believe selling our customers more, or less, than what their application calls for. For over two decades working with our customers we’ve developed a broad range of options and accessories to address the majority of ultra-precision motion applications. (See options and accessories for a complete list.)

    No matter how broad our product options, we realize they don’t address every possible application. Our precision motion experts will work closely with you to configure a rotary motion solution that will meet your exact needs.

Land & Marine
Custom Large Clear Aperture
Custom Grind Table
Custom 17" Clear Aperture Air Bearing


  • Motor drives and controls
  • Encoders and digital readouts (DRO)
  • Vacuum worktable and controller to hold sensitive lightweight parts safely and securely
  • Custom bolt circle patterns
  • Standard and custom size clear apertures


  • ABTech Precision Centering Fixtures
  • Custom fixturing and work holder tooling
  • Gage stands
  • MicroTIR electronic gage packages
    • µTIR-10: display with single lever-type electronic indicator
    • µTIR-11: display with single lever-type electronic indicator and encoder interface
    • µTIR-20: display with dual lever-type electronic indicators
    • µTIR-21: display with dual lever-type electronic indicators and encoder interface
  • Granite surface plates
  • Structural steel frames with passive vibration isolation leveling feet
  • Certified 2µ” round master test ball and cover

Air Bearing Rotary Table Specifications

Certified Accuracy
Radial & Axial<2.0 µ” (0.05 µm)<10.0 µ” (0.250 µm)
Tilt (Coning)<0.206 arc sec or 1.0µ”/in (0.025 µm/25mm)
Working Envelope
Maximum Part Diameter
305 mm
406 mm
610 mm
813 mm
1.0 m
1.2 m
Axial Load Capacity300 lbs
136 Kg
500 lbs
226 Kg
1,200 lbs
544 Kg
2,000 lbs
907 Kg
3,000 lbs
1,361 Kg
5,000 lbs
2,268 Kg
Worktable Diameter6"
152 mm
203 mm
305 mm
406 mm
508 mm
610 mm
Tapped holes1/4 -28 UNF
Worktable Configuration
Tilt and Center4-knob spherical seat8-knob spherical seatn/a
Knob Configuration2 centering, 2 leveling at 90⁰4 centering , 4 leveling at 90⁰n/a
Air Consumption2.0 cfm @ 60 psi with dual stage filter/regulator4.0 cfm @ 60 psi with dual stage filter/regulator
Product Dimension9.25" OD x 5.50" T
235 x 140 mm
12.63" OD x 7.25" T
321 x 184 mm
17.25" OD x 8.50" T
438 x 216 mm
19.00" OD x 8.00" T
483 x 203 mm
22.00" OD x 3.40" T
560 x 86 mm
26.00" OD x 3.50" T
660 x 89 mm
Product Weight50 lbs
23 kg
100 lbs
45 kg
240 lbs
110 kg
450 lbs
200 kg
220 lbs
100 kg
300 lbs
140 kg
*Limited by tilt and center worktable. Higher load capacity available upon request.

Motor Drive Options

With proper selection and integration of high-performance brushless DC servo motors ABTech’s air bearing rotary tables provide ultra-smooth and precise rotary motion. With high torque, high performance motor drives, our motion experts will gather your specific requirements and work closely with our motor suppliers to create/select a motor drive that suits your specific application. Whether you need sub-micron position accuracy with minimal settle time and stringent following error specifications, high-speed constant motion, or a combination of both there is an ABTech rotary table that will meet your needs.

The motor drives are designed to accommodate a wide range of precision motion applications such as optical metrology; circular geometry gages; and micro machining with ultra-precision scanning, velocity control, speed regulation and precision indexing.

ABTech’s modular design approach facilitates multiple system configurations to optimize the price-for-performance required in your application. This approach allows the user to define the level of control desired for the most cost-effective solution. Our complete engineering services allow us to respond quickly to provide a solution to your O.E.M. requirements for ultra-precision rotary motion.

AT 100
AT 100
AT 200 Direct Drive 1.25arcsec accuracy
AT 200 Direct Drive 1.25arcsec accuracy
AT 100 Foot Mount
AT 100 Foot Mount
AT 200 with variable speed motor, friction clutch and onboard DRO
AT 200 with variable speed motor, friction clutch and onboard DRO
AT 200 Direct Drive with/ TC8
AT 200 Direct Drive with/ TC8
AT 200 Wet Grind Table
AT 200 Wet Grind Table


Thank you for your interest in ABTech’s ultra-precision measurement tools and services.
Please tell us a little about what you need to accomplish and we will be in touch to discuss any of the additional details that will help you choose your best option.

Thanks a lot for your help. Your rapid, informative correspondence was invaluable. Hopefully I won't be bothering you with any further questions, but it's good to know you're willing. (following remote technical support provided for system installed at the South Pole) Morgan HedgesPost-doctoral Research Associate
Princeton University
Made in the U.S.A.

Every product we sell exemplifies our company-wide commitment to "Pride in Precision" craftsmanship. To that end, all of our products are designed, manufactured, and tested exclusively by ABTech at our New Hampshire facility.

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