UT Test Block NavShip Phased Array/1018 Steel Nickel plated ultrasonic Calibration Block 6 holes type

Overview
Inch
Contains six 3/64 diameter side-drilled through-holes at distances of 0.25 to 2.75 in 0.25 increments. MTDs are engraved near both scan edges on one face. In accordance with MIL-STD-271G Figure 9, and NAVSHIPS Specification 0900-006-3010/Section 6. Also known as a Mare Island block. This block is surface ground to a 32 Ra finish on all surfaces,

• Dimensions: 12.000 x 3.000 x 1.250
• material:1018 Steel Nickel plated

The drawing of it: