Metrology & Flatness

Our Metrology Equipment

Measuring Instruments used for Flatness, Thickness and the Surface Finish of workpieces

We utilize a variety of fast and reliable instruments to evaluate the diverse finishes that are needed to be achieved throughout the industry. What you will find in our metrology lab is the latest technology equipment to get the most precise reading that needs to be achieved. This ultimately assures you the accuracy in surface finish, flatness, and thickness measurements of a part. We have the tools of measuring down to the tenth of a micron. We are ISO 9001:2015 Certified to provide you with the high-quality standards that we continuously stand by.

Stahli USA offers flatness measurements of three different types:

Zygo Optical flatness measurement reliable to the nanometer range accuracy

Zygo Instrument – Optical flatness measurement reliable to the nanometer range accuracy. Typically used when measuring very small parts or step dimensions.

Optical flatness measurement reliable to the micron range accuracy

LamTec Instrument – Optical flatness measurement that’s reliable to the micron range accuracy. This is typically used when measuring a wide range of parts, specifically 11+ inches in diameter.

optical flats

Optical Flats – We can special order optical flats for any size parts.


We go above and beyond in providing the finish that is needed to be achieved. Feel confident in our results with our data provided with the precision and relability you will recieve working with Stahli. Surface Finish readings can often be overlooked while creating a new process. We often see companies run into this issue which is why Stahli USA continuously dedicates in only using the latest technology. Precision and quality is what we take pride in. Any surface texture can be measured at Stahli USA by utilizing different methods:

Taylor Hobson reads in nanometer range and measure texture of the workpiece

Taylor Hobson – A physical measurement of the texture of a part. It uses a stylus that can traverse most materials and read to the nanometer range

3-D texture analysis of workpiece

Zygo Instrument – Optical 3-D texture analysis with the ability to read in the nanometer range


Measuring the thickness of flat pieces are done at Stahli USA through the use of a Brunswick instrument with accuracy to the nanometer range. In addition, we have the tools to measure the step dimensions and counterbores by using step gauges.

Portable tool used to physically measure pieces of any size

Mitutoyo – Portable physical measurements on our shop floor for fast texture analysis

Parallelism and flatness measurement in the nanometer range

Brunswick – Measures thickness, parallelism, and flatness down to the nanometer range.


  • Zygo – Measurement of parts from 0.020 inches to 3 inches in diameter

The Zygo is a 3D optical profiler that is a non-contact surface measurement instrument. It has the ability to read of micro- and nano-scale surfaces. In relation to the Zygo being a 3D profiler, this instrument is able to provide both flatness and the surface finish readings of a workpiece. This measurement tool produces accurate and repeatable measurements. Although, it’s main focus is for readings of smaller workpieces.

  • LamTec – Measurement of parts from 0.25 inches to 11+ inches in diameter

The LamTec is our latest addition to our metrology lab. It replaces the Tropel that was our main measuring instrument for flatness readings. The LamTech and Tropel both achieve the same performance standards although the lamtech adds to its capability. Particularly, the LamTech allows measureing of a workpiece surface without direct contact with the glass. The Tropel does require contact which can potentially lead to an innacrate reading. This will happen if the workpiece is not fully clean of substance that was in use during the finishing applications. In addition to this happening, causes the instrument to read the substance as part of the workpiece surface area. The LamTech allows us to completely avoid inaccurate measurements with the no contact feature. In addition, the LapTech instrument allows us to measure the flatness of workpieces bigger than 11 inches. Which in turn, the tropel is not capable of achieving.

  • .Optical Flats – Built for your specific needs

Optical flats are an optical-grade piece of glass that is lapped and polished on both sides creating an extremely flat surface. This is to use for referencing towad the flatness of an unknown surface for comparison. An interferometer is used as a light source while the optical flat is placed on top of the workpiece you are trying to get measurements for. Therefore, you will then be able to measure the workpiece by the light bands within the surface to precisely give an accurate flatness of the finished part.

Surface Finish:

The taylor hobson is used for the measurement of the finish part surface

Taylor Hobson – Measuring of the part surface

Thickness Measurement tool

Mitutoyo – A portable measurement tool for flat pieces that satifies any size part.

3D measurement view of workpiece finish part

Zygo – 3D measurement of parts

Stahli USA encourages our cosutomers to visit our facility to witness first hand the precision and reliability thats achiveved on a daily basis. We can accomodate to wide vaieties of thickness measurment(s) while holding or exceeding surface requirments. Call us today to meet with one of our specialists and test your workpieces on our equipment.

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