Main types of surface flaw and characteristic, difference of detectability by flaw detection method are indicated in following table:
|Flaw Name||Characteristic and Shape||Form of Cross Section||Surface property||Eddy Current Tester||Magnetic Leakage Flex Tester|
|Seam Crack||Linear shape flaw which occurs in longitudinal direction continuously||△～×||〇||〇|
|Creases||Creases shape flaw which occurs on contacting surface||△～×||〇|
|Fold||Fold flaw which along the rolling direction||△～×||〇|
|Scab||Peel off of surface, wrap shaped flaw||〇～△||〇||〇～△||〇～△|
|Rough Surface||The flaw which surface got uneven by getting rough||△||〇||△||△|
|Dent||Dent flaw which occurs locally||×||〇||×||×|
|Scab Crack||Crack which is originated from scab flaw||〇||〇||〇||〇||〇|
: Depend on the direction of scanning
It is appropriate for the final inspection of the target material which has smooth surface after the process such as wire drawing or peeling.
Example: metal, nonferrous metal bar (Stainless, aluminum, copper), cold finished steel bar, steel pipe, wire, drawn wire, etc.
It is appropriate for the inspection of the material which has rough surface and is at the initial stage of processing such as after forming process by rolling.
Example: Round bar, Steel pipe, Black steel round bar, other strong magnetic material