Types of impact device DC(D)/DL, D+15, C , G , E(imported)

D: General test.
DC : Testing hole or inner of cylinder.
DL : Test slender narrow groove or hole.
D+15 : Test groove or reentrant surface.
C : Test small, light, thin parts and surface of hardened layer.
G : Test large, thick, heavy and rough surface cast steel.
E : Test super high hardness Material.