MAC® offers Eddy Current, Electromagnetic, Flux Leakage and Ultrasonic solutions for on- or off-line testing of hex, round and other dimensions. Parts may be submitted for a free evaluation and analysis conducted by MAC’s certified engineers to determine the best NDT option for your application.

  • Typical flaws and conditions that can be detected include cracks, variations in alloy, grade or heat treatment, unwanted inclusions, seam and weld defects as well as some dimensional variations and other conditions.
  • Recommended for Military Ordinance, Automotive, Medical and a variety of other industries.
  • Our experienced Field Engineers can help to integrate your feed mechanisms with MAC testers.
  • Typical parts sorters and inspection equipment include the Varimac® VI and the Production Comparator.

Parts that can be tested include washers, coil springs, bearing races, inner bearings, outer bearings, roller bearings, ball bearings, ball joints, pivot bushings, fasteners, pistons, strut rods, CV joints, expanders, metal gas connectors, piston pins, metal stampings, rivets, nails, screws, clips, threaded inserts, nuts, studs, roller chain plates, bearing pins and rollers, grenades, ordinance shell bodies, ordinance shell bases, medical needles, surgical blades, and other parts as well as tubes, bars, plates and wires.


Low-frequency Tester for Ferromagnetic Materials

Detects Variations in Alloy, Heat Treatment or Case Depth

  • Rapid sorting of ferromagnetic parts with non-destructive testing (NDT).
  • Offers choice of Polar (Vector) or Lissajou screen displays.
  • Inspect tubes or bars at production line speeds.
  • Choose any one of 10 pre-set frequencies from 10 Hz to 150 Hz.
  • Optional 8-channel multi-frequency software is available.
  • System can be set up and monitored on site or used via computer at a remote location.
  • Monitor presentation provides simultaneous display of the “standard” piece and test piece waveforms for easy comparison.


Tests Hardness, Alloy, Dimensions and Physical Characteristics in Metal

  • Test and sort fasteners, bearings and other cold formed pieces using 100% nondestructive testing.
  • Check for hardness and correct grade in wire and bar.
  • Test ferrous (magnetic) or nonferrous (non-magnetic) material.
  • Use with MAC® Parts Gate for high-speed 3-way sorting.
  • Selective circuits separate wanted signals from those of unwanted conditions.
  • Contact MAC to arrange for a no charge comparator trial test of your product.

The Varimac® VI performs fast, convenient sorting of metal parts. When used with MAC’s Part Gates, parts can be sorted and counted at speeds up to six parts per second into three separate groups.


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.

  • 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.


A frequent challenge in manufacturing and industry is how to separate different parts that have been intentionally—or accidentally—mixed. Electromagnetic comparators can be used to accomplish this quickly and economically.

  • This type of instrument “compares” variations in a test part to conditions in a known sample.


  • When a metal part is placed inside or near a test coil that is excited by an alternating current, the voltage output from the coil will be affected. This is the basic principle employed by all electromagnetic comparators.
  • The kinds of mixes that comparators will separate typically involve variations in alloy, heat treatment, hardness, structure and dimensions (including length) .

570 Parts Gate