Flux Leakage Tester for Detecting Surface Defects in Hot Rolled Black Steel Bar

  • Designed to test hot rolled bar from 15mm to 130mm in diameter.
  • Incorporates wireless signal transfer features to minimize noise while maximizing sensitivity.
  • Detects longitudinal flaws as small as 0.1mm deep on hot rolled bars and rods, depending on the material condition.
  • Operates up to 1500 rpm, depending on product diameter.
  • A simple adjustment tool allows for quick resetting for dimensional changes.
  • Operates with Rotoflux® AC electronics.

130mm AC Flux Leakage Unit

The Rotoflux® AC combines superior technology and performance, and offers these additional important features:

  • Provides full quadrature detection to preserve phase selectability.
  • Choice of all phase and chord gates, similar to a conventional Eddy Current tester.
  • New Probe screen offers sensitivity and phase adjustment for each individual channel.
  • Features 2 surface ride Probe Arrays consisting of 8 elements, each covering up to 160mm per rotation.
  • Throughput speed of up to 4m/s (800 FPM). Larger diameters require slower FPM speeds.
  • Shares common graphic user interface with other MAC systems such as UT and EC testers.
  • 180mm unit also available.


Highly sensitive AC flux leakage is especially well suited to test hot rolled black steel bars and rods that have surface conditions which used to make finding shallow defects very difficult, if not impossible.

  • AC flux leakage systems use two magnetization yokes and alternating current to induce an alternating magnetic field.
  • Without contact, these yokes magnetize the test material in the transverse direction.
  • The magnetic flux is concentrated on the material’s surface due to eddy current effect, and is particularly sensitive to minor surface defects since the operating probe examines a very small portion of the entire surface at any one moment.
  • MAC’s® Rotoflux® AC Flux Leakage Tester was designed for use with materials such as hot rolled black bar and can find defects as small as 0.1mm deep, depending on the material condition.