SEP 1921 (U.T)

This spec is applicable to forged and hot-rolled, raw or processed steel bars in alloyed or non-alloyed steels, in natural state or treated condition. The inspection method for the search of internal defects can be freely chosen by the supplier (instrumentation, 1-4 MHz probes, coupling methods, etc.) as long as the test is carried out on the entire number of pieces. Defect recording must be done according to the F.B.H. (flat-bottom-hole) method. All defects (indications) bigger than the agreed-upon values must be described according to their position, size, extension and have to be reproduced in a drawing. Such a condition has to be sent to the Lucefin Group’s Technical Department for evaluation.
Acceptance limits            
Table 1              
Size Category Single defects Defects with extension Max. extension
mm FBH  (1) FBH  mm  mm
A 14 10 80
B 10 7 60
C 7 5 40
D 5 3 30
E 3 2 30
(1) The distance between single defects must be min. 50 mm; where the distance is lower, defects must be 
considered with their extension.          
Number of defects on individual pieces        
Table 2              
Frequency Category Number of defects Number of defects with extension
a 32 16
b 16 8
c 8 4
d 4 2
e 2 1