Deep drawing and pressing thin the sheet where deformation is most severe: edges, fillet radii, the bottom of ribs. Callipers cannot reach there, ultrasonic measurement can, and it works from one side only.
- ✓ Measurement from one side only, without dismantling or cutting the part
- ✓ Resolution down to 0.001 mm on the Precision range
- ✓ Sheet thickness check on incoming supplier goods
- ✓ Data logger for the grid of points and the inspection report
A pressed part does not have the thickness of the starting strip. Plastic deformation redistributes the material, and in the zones where elongation is greatest the wall thins. The thinnest point is almost always in a position that cannot be reached with callipers or a micrometer, because that would require access to both faces.
Ultrasonic measurement solves the access problem: the probe rests on the outer face and the instrument returns the thickness by reading the return time of the echo from the opposite surface. On thin thicknesses, typical of sheet for pressing, high-frequency probes with a delay line and an instrument from the Precision range are needed, not a gauge designed for corrosion.
Need help choosing the right product?
The same instrument is useful upstream of the process. Checking on receipt that the strip or sheet has the thickness declared by the supplier is a quick control that catches a problem before it becomes press scrap, and it is documented with the readings stored in the data logger.
Where to measure on a pressed part
| Zone | What is checked |
|---|---|
| Fillet radii and edges | Maximum thinning due to elongation of the material |
| Bottom of ribs and deep drawn features | Thickness reduction in severely deformed zones |
| Flat zones away from the deformation | Comparison reference, close to the starting thickness |
| Strip or sheet on receipt | Match between the thickness supplied and the thickness declared |
| Parts from the start and end of the batch | Process drift and die wear |
How the inspection is set up
The first step is calibration on the propagation velocity of the actual material: steel, stainless steel and aluminium have different velocities, and a wrong value shifts the reading systematically. On a reference block of the same material the calibration takes a few minutes.
The second is defining the grid of points. Fixing the positions once and for all, and using them on every part inspected, makes the values comparable over time and allows die drift to be recognised before it produces out-of-tolerance parts. The models with a data logger keep the grid and export it to DakMaster™ for the report.
Recommended instruments
| Instrument | Typical use |
|---|---|
| Dakota PMX2-DL | Precision measurement with A-Scan, resolution down to 0.001 mm |
| Dakota PZX1-DL | Thin materials, quality control in production |
| Dakota CX2 | Quick incoming check on uncoated surfaces |
| Precision transducers | High-frequency delay line probes for thin thicknesses |
Frequently asked questions
No. Ultrasonic measurement is carried out from one side only: the probe rests on the accessible face and the instrument reads the echo returning from the opposite surface.
Because corrosion instruments are optimised for greater thicknesses and coarser resolutions. On thin sheet the Precision range and high-frequency delay line probes are needed.
Yes, but an instrument with the Echo-Echo mode is required, which ignores the coating layer and returns the metal thickness alone. In Pulse-Echo mode the coating would be counted in.
Back to Automotive and Motorsport, or write to us from the Contacts page: tell us the material and nominal thickness and we will propose the right instrument and probe combination.
Further information and contacts
Systems division and sensor integration partner : www.roder.it
More information about RODER SRL : about us
Contact for general information : info@roder.it
Contact for information about these products : info@roder.it
The information contained on this web page is provided for information purposes only. Although it has been compiled with the utmost care, it does not constitute a contractual offer or a binding commitment to supply. It may contain transcription, translation or typographical errors. For precise and up-to-date information, please contact our company directly.
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