Ultrasonic Phased Array:

MAC can offer Phased Array technology to allow simple testing of both round corner square billets and large round billets. MAC has a unique Phased Array cassette system that allows quick change between the two major geometries (round or square). The transducer assemblies follow the product surface and allow the testing to be optimized relative to the bar center.

Eddy Current/Ultrasonic Multi-Test:

MAC can supply a combined Eddy Current and Ultrasonic system for inspecting hot rolled square and round billets up to 9” (228.6mm) in diameter.

  • The 8-channel eddy current test uses both sector and rotary test probes to detect defects on the flat surfaces and corners. Square or round corner billets can be tested.
  • The UT system can be Phased Array or conventional array type testing. The UT method detects internal defects and makes it possible to volumetrically inspect large bar product.
  • These tests meet MIL STD 2154 standards.

Custom Eddy Current system tests billets using rotary probes to inspect flat surfaces and tangent coils for the corners

MultiMac® Eddy Current Billet System

  • Detects longitudinal defects in the flat surfaces, detects transverse and longitudinal flaws on the corners.
  • MultiMac® electronics have eight test channels.
  • Test frequencies can be selected from 1 kHz to 5 MHz with a flaw bandwidth
    up to 5 kHz.
  • Set-up can be accomplished in less than 10 minutes and a size change only requires an adjustment of the headplate probes.
  • The MultiMac® electronics used in the billet test system have a full Windows® based user interface, making it easy and intuitive to operate.

Eddy Current tangent coils test billet corners

Echomac® FD6 Ultrasonic Billet Inspection System

  • Echomac®FD6 UT test electronics with 48 channels are expandable to 64 channels.
  • Mechanical operation consists of four transducer test heads, each with three surface ride shoes containing three or four transducers, and one bubbler for coupling purposes.
  • A tracking and marking system is available to identify indications.
  • Features an offline calibration station and an integrated water circulating and cooling system.


High-speed Ultrasonic (UT) Systems enable a full volumetric examination of materials and are designed to detect surface, subsurface, internal and dimensional flaws.

This type of testing utilizes high-frequency sound waves that are transmitted throughout the material being tested in order to conduct a thorough inspection.

  • Ultrasonic inspection can be used to detect surface flaws, such as cracks, seams, and internal flaws such as voids or inclusions of foreign material. It’s also used to measure wall thickness in tubes and diameters of bars.
  • An ultrasonic wave is a mechanical vibration or pressure wave similar to audible sound, but with a much higher vibration frequency. For NDT purposes, the range is usually from 1MHz to 30MHz or higher.
  • Depending on the test requirements, these waves can be highly directional and focused on a small spot or thin line, or limited to a very short duration.
  • Two methods of UT are used for flaw detection – Shear and Compression Wave.


MAC’s® Eddy Current Testing (ECT) systems incorporate computer-based test instruments and test coils that use two ECT coil technologies: encircling and sector coils, and spinning or rotary probe coils.

This type of testing utilizes high-frequency sound waves that are transmitted throughout the material being tested in order to conduct a thorough inspection.

  • Encircling and sector Eddy Current coil tests perform in this manner:
  • The product is passed through or adjacent to an electrical test coil, which has been excited by an alternating current.
  • This induces a flow of eddy currents around the test material or in the case of a sector coil, in the area under the coil.
  • Short, intermittent anomalies or flaws cause a variation in the eddy current pattern, which the instrument detects.

MAC’s vivid real time test screen displays results for easy review