Eddy-current testing

In many cases, BESSEY is able to offer surface defect testing using eddy-current testing as standard.


Thanks to the addition of a new eddy-current crack detection system, which we brought on-line in May 2011, we are able to detect the smallest of surface defects over a wide range of different product sizes.

Surface quality grades 1 2 3 4
Permitted defect depth

Max. 0.3 mm

for d ≤ 15 mm

Max. 0.3 mm

for d ≤ 15 mm

Max. 0.2 mm

for d ≤ 20 mm

Manufactured to be free of cracks

(only possible with a subsequent machining)

Max. 0.02 x d

for 15 < d ≤ 100 mm

Max. 0.02 x d

for 15 < d ≤ 75 mm

Max. 0.01 x d

for 20 < d ≤ 75 mm

Max.1.5 mm

for d > 75 mm

Max. 0.75 mm

for d > 75 mm

Max. percentage of delivery weight
above the established defect limit
4 % 1 % 1 % 0.2 %

( d= nominal diameter of the rod or distance between parallel surfaces on square and hexagonal bars)


Test methods: Circograph (rotating scanning probes) and Defektomat (encircling through-type coils)

Dimension: round 6-50 mm / hexagonal 6-36 mm / square on request