ASTM A 108 d (Defects)

Tolerance Surface discontinuity tolerances 
Carbon and Alloy
Non-resulfurized
Carbon and Alloy
Resulfurized (0,08 – 0,19 % sulfur)
Carbon and Alloy
Resulfurized (0,20 – 0,35 % sulfur)
dimensions  mm 6,35 thru 15,88  15,88 thru 152,40  6,35 thru 15,88  15,88 thru 152,40  6,35 thru 15,88  6,35 thru 15,88 
  maximum depth maximum depth maximum depth maximum depth maximum depth maximum depth
  mm  % mm  % mm  %
Level   1 0,20 1,6% 0,25 2,0% 0,30 2,4%
Level   2 0,15 1,0% 0,20 1,3% 0,25 1,6%
Level   3 0,15 0,75% 0,15 1,0% 0,20 1,3%
Level   4 (b) nil nil nil nil nil nil
(a) The information in the chart is the expected maximum surface discontinuity depth within the limits of good manufacturing pratice. Occasional bars in a shipment may have surface discontinuity that exceed these limits. For critical applications, the purchaser may require the cold finish steel bar supplier to eddy current test the bars prior to shipment.
(b) Level 4 requires metal removal by turning or multiple grinding passes for small bars