MicroForm µFG450 Roundness Gage
MicroForm µFG450 Roundness Gage
MicroForm µFG450 Large Capacity Roundness Gage with Vertical Gage Arm
MicroForm µFG450 Large Capacity Roundness Gage with Vertical Gage Arm
Nobody makes such a nice and robust tilt and center assembly. The load rating exceeds any equivalent stage on the market and the workmanship is amazing.
Luke Gers
Optical Engineer
Callaghan Innovation (New Zealand)


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Large Tower  –  Single & Dual Probe

(Max Part Size: 32” dia. x 60” tall, Max Part & Fixture Weight: 2,000 lbs)

With their ability to perform ultra-precision form measurement on even the largest parts, our turnkey large capacity roundness gages are unique in the industry.  With worktable diameters up to 48” and with our counterbalanced tower designs, the sky is the limit (almost) for vertical height of the probe.

Our roundness gages incorporate an ABTech designed and built air bearing rotary table that delivers ultra-precision results. A powerful yet intuitive user interface simplifies navigation, displaying the results in a familiar way. These ease-of-use features allow operators of all skills levels to take exacting measurements on the shop floor or in the QC lab.

MicroForm gage platforms measure roundness, flatness, concentricity (in and out of plane), parallelism and perpendicularity.  Our unique RunOut feature simplifies part alignment and provides quick in-process shop floor checks. For precise part alignment and to reduce eccentricity errors, gages can be configured with an adjustable Tilt and Center worktable.

Currently have a gage that’s functional but isn’t quite cutting it?

If you don’t need a new gage we don’t want to sell you one. Save thousands of dollars by upgrading your current air bearing-based gage with a new MicroForm controller and software. We’ll also work with you to customize your platform to address unique applications.

For more detailed specifications read more in the tabs below or view the datasheet for this product.

To learn more about software for this product, view the MicroForm Software datasheet.

Features & Benefits

Accurate and Repeatable

An ultra-precision air bearing rotary axis is the foundation for all MicroForm gages. Standard single lever-type probe or optional dual probes with nearly perfect linearity (correlation coefficient of .9999 out of a possible 1.0000) contribute to an overall system accuracy under 5 millionths of an inch ( 0.125 μm). Systems with capacities of over 2,000 lbs have an accuracy of 10 millionths of an inch (0.250 μm). With no mechanical contacting parts to wear or create drag, air bearings produce virtually no friction. This translates into ultra-smooth, repeatable and maintenance-free operation.

Stable and Reliable

Frustrated by frequent measurement errors? Our platforms have engineered out the most common causes of errors such as thermal and/or vibration interference from interference from internal electrical components. The motor drive amplifier, power supplies and other electronic hardware are installed in the MicroForm controller isolating then from the part. Minimal cabling and connectors help reduce electrical interferences that could distort your measurements. To maximize thermal and vibration stability, the air bearing is recessed in a granite base and the granite surface plates are mounted on structural steel frames with passive vibration isolation leveling feet. With this robust design, you can be confident that your measurement result is from the part alone, and don’t include “noise” from outside influences.

Quick Part and Probe Setup

Fine adjust features on both the horizontal and vertical arm allow precise alignment of the probe tip to the measurement surface from the tower. On other systems, adjustments are made on the gage head making it difficult to reach on large parts.

To make multiple surface measurements quicker, our dual probe configuration comes with an additional portable or fixed gage stand that can be mounted on the granite surface plate with a second electronic indicator.

With the Tilt and Center adjustable worktable operators can make very fine adjustments to level and align parts to the bearing’s axis of rotation, reducing eccentricity. The spherical seat design maintains the part’s center point when leveling, saving you time and frustration in setting up the part for measurement.

Based on the large girth and short stature of your parts the gage stand was configured to offer the most stability and robustness for the extended radial reach required. A secondary vertical probe arm provides easy access to ID surfaces in deep bores. The gage stand can be encoded so the vertical position can be captured directly into the MicroForm measurement software.

Familiar User Interface with Touch Screen Navigation

We’ve designed our measurement program to display results in a fashion that is familiar for shop floor operators while providing full function analysis for quality control labs. In the case of a user interface often less in more. MicroForm’s intuitive software features two simple views on a large color touch screen monitor, delivering quick and easy results whether you’re a novice or experienced operator. Toggle between the main setup screen with active analog and digital runout meters, to the results screen with graphical polar and linear charts. A sidebar menu of all the form options along with measurement results are always visible And for novice operators, on screen “step-by-step” instructions are available. (Learn more about MicroForm software.)

Operators interface with Mircoform gage using a large 22” touch screen. Two simple screens are used to clearly lay out access and navigation. Operators can easily toggle between the main setup screen with its active analog and digital RunOut meters, to the results screen with graphical polar and linear charts. Measurement results and a sidebar menu of all the form options are always visible.

Unique Dedicated Processing Power for Fast Measurements

Our gages are driven by a “real-time” operating system with dedicated FPGA processing platform and signal conditioners. These are the workhorses for performing the measurement algorithms, eliminating resource conflicts typical with systems running on PCs. The gage’s dedicated processor results in high speed data acquisition and instantaneously synchronizes the indicator displacement with a high resolution encoder for pin-point accuracy. This powerful processing platform not only provides tremendous system performance but also permits future system enhancements without the cost and downtime associated with hardware obsolescence.

A Spectrum of Analysis Functionality

To ensure quick and accurate measurements, surface interruptions can be automatically removed during a measurement or easily edited out using our drag and exclude feature. You also have the flexibility to analyze part harmonics (slope and lobing optional) right on the results screen or export the data for statistical process control (SPC).

User definable system preferences for customizing output and displays are readily accessible through the configuration button. Select from four reference circle types: Least Squares Circle (LSC), Minimum Zone Circle (MRS), Minimum Inscribed Circle (MIC), and Maximum Circumscribed Circle (MCC), Gaussian filter settings, units of measure, and other options to match your part drawing’s requirement.

Quickly print or save a PDF file to share the measurement results and graphical charts and document traceability. And each PC includes an Ethernet network card to provide remote file storage and enterprise connectivity.

MicroForm™ Software

for Precision Measurement

A straightforward interface which increases productivity, streamlines training, and offers the highest degree of operator flexibility. The full functionally is made easy so operators of every skill level can use our gages. The maximized interface accommodates different skill levels with on screen “step by step” instructions that don’t interrupt an experience user. All MicroForm gages offer a dual probe option to enhance the measurement process.

Read more about our MicroForm™ Software

Measurement Results Showing Interrupted Surfaces


Working envelope:

  • Axial load capacity (max centered and balanced): 2,000 lbs (907 Kg)
  • Max part diameter (swing): 32″ (813 mm)
  • Max part height (OD probe access): 60″ (1,524 mm) with 48″
  • Height to worktable: 30″ (762 mm)

Gage system certified accuracy:

  • Radial & Axial accuracy: <5.0 µ" (0.125 µm)
  • Tilt accuracy: <0.206 arc sec or 1.0µ"/in (0.025 µm/25mm)


  • Rotary air bearing table (Model AT400)
    • Integrated motor with clutch for manual rotation
    • 440 hardened stainless steel
    • Grade A granite base dimensions: 60″ x 36″ x 10″
    • Frame construction: welded steel base with vibration isolation feet
    • High resolution rotary encoder
    • Air consumption: 2.0 cfm @ 60 psi
  • Spherical seat type tilt and center adjustable worktable (Model TC8-400)
    • 16” (406 mm) diameter worktable with 2.0″ (50.8 mm) thru hole with removable plug
    • Concentric ″V″ grooves in worktable equally spaced for rough centering
    • 1/4-28 tapped holes in worktable
    • Eight fine pitch screw type opposing knobs (4 centering, 4 leveling at 90⁰) for precise tilt and center adjustments
  • Counterbalanced tower style gage stand
    • Vertical travel: 60” (1.5 m)
    • Horizontal travel: 28” (711 mm); coarse manual height and arm adjustments; position locks with fine gage head adjustments
    • 48″ (1.2 m) secondary deep bore vertical arm with lever-type electronic gage head
    • Mount (second probe): MicroForm Ultra-fine adjust probe mount (#07000A)
  • Dual element air filter/regulator for air bearing supply (Model 00938A)
    • 5.0 micron pre-filter w/ regulator (0 – 150 PSI)
    • 0.3 micron second stage filter, oil/water removing (coalescing)
  • Metrology controller
    • Independent electrical box contains “FPGA” based “real-time” operating system, encoder interface, signal conditioners, and power supply
  • Mobile electronics cabinet with:
    • Swivel and locking casters for easy mobility
    • Adjustable shelf for keyboard and mouse
    • Shelf for MicroForm controller and PC with optional printer tray
    • Articulating touch screen monitor mount
  • Windows OS PC with 22″ color touch screen monitor, keyboard and mouse
    • Ethernet connection for network connectivity
  • MicroForm metrology software suite
    • Measure standard geometric forms:
      • Roundness, Flatness, Parallelism, Runout, Perpendicularity (Squareness) and Concentricity (in a single plane and in two planes) with reference axis setup
    • Setup screen with analog and DRO displays for checking TIR and part alignment
    • SAE and Metric units (standard and micro)
    • User definable Gaussian filter UPR’s and display/output and plot settings
    • Manual and automatic editing of interrupted surfaces
    • Harmonic analysis feature for identifying undulations per revolution (chatter)
    • Save and print measurement results
    • Save and access raw data for statistical process control (SPC) or further analysis

All specifications are at 60 psi and subject to change without notice.


  • Heavy-Duty HDTC4 style fine adjust Tilt and Center worktable
  • Motor drive with clutch for free rotation
  • Larger diameter and/or customized worktables and/or extension arms (up to 32″ diameter)
  • Second gage stand and probe with dual probe software upgrade
  • Retrofitting services


  • Optional probe tips (material and length)
  • Fixtures (3-jaw chucks, Precision Centering Fixture “PCF-400”, etc.)
  • Certified 2µ” round master test ball and cover


  • Aerospace
  • Aviation
  • Automotive
  • Precision optics
  • Bearings
  • Semiconductor

MicroForm gages are used for as variety of manufacturing and quality functions including:

  • In-coming inspection for vendor compliance
  • In-process tolerance confirmation
  • Manufacturing process control and improvement
  • Quality control and part analysis

Similar Products:

    AT200 with TC8 Tilt & Center Worktable AT200 (8″ Ø)
    EAS3000-2T P07 Standard Configuration EAS3000-2T
    AT300 With TC8 Tilt and Center Worktable AT300 (12″ Ø)
    AT400 with TC8 Tilt and Center Worktable AT400 (16″ Ø)
    HDRT Heavy Duty Series HDRT550 (22″ Ø)
    HDRT Heavy Duty Series HDRT660 (26″ Ø)
    MicroForm Model MFG200 µFG200
    MicroForm Model MFG200T µFG200T
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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.

I just wanted to let you know that the fixture that you provided was exactly what we need to check the parts we have. Thank you for your efforts in facilitating this tool. If we ever need anything like this tool in the future we will be sure to contact you. Mark MichelsenManufacturing Engineer
Varian Medical Products
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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