The MIL-STD-271F Magnetic Particle Test Plate contains (2) EDM notches at 0.020" deep x 0.006" wide x 0.063" long. Material is 3/8" thick low alloy steel x 6" wide x 12" long. Notches are filled flush with a nonconducting material, such as epoxy, to prevent mechanical holding of the indicating medium. One notch is oriented parallel to the weld, the other perpendicular to the weld. In accordance with MIL-STD-271F (SHIPS), Paragraph 220.127.116.11. Also meets requirements of newer NAVSEA Tech Pub T9074-AS-GIB-010 /271, Paragraph 18.104.22.168.