w/INT. AMENDMENT 2
that all administrative functions for the establishment of a new CSTA project have been
completed in preparation for the test. The contracting government activity is to initiate the
new project through a letter to Commander, US Army CSTA, ATTN: AMSTE-TO-O,
Aberdeen Proving Ground, MD 21005-5059 requesting a cost estimate for the ballistic
testing of the applicable number and sizes of plates. In the case of increases in scope of
existing projects, similar correspondence is needed.
6.10.1 Slivers. An imperfection consisting of a very thin elongated piece of metal attached
by only one end to the parent metal into whose surface it has been worked.
6.10.2 Laps. A surface imperfection with the appearance of a seam, caused by hot metal,
fins or sharp corners being folded over and thus being forged or rolled into the surface but
without being welded.
6.10.3 Checks. Checks are numerous very fine cracks at the surface of a metal part. Checks
may appear during processing or during service and are most often associated with thermal
cycling or thermal treatment. Also called check marks, checking, heat checks.
6.10.4 Seams. Seams are an unwelded fold or lap that appears as a crack, usually resulting
from a discontinuity on a metal surface.
6.10.5 Blisters. A raised area, often dome shaped, resulting from delamination under
pressure of expanding gas trapped in metal in a near sub-surface zone. Very small blisters
may be called pinhead blisters or pepper blisters.
6.10.6 Snakes. Any crooked surface imperfection in a metal plate, resembling a snake.
6.10.7 Cold shuts. A lap on the surface of a forging or billet that was closed without fusion
6.10.8 Burning. Permanently damaged metal due to overheating enough to cause incipient
melting or intergranular oxidations. Note: This condition is usually obscured by normal
cleaning methods and would require deep pickling and/or metallography to note the
continuous oxidation (chicken wire effect) of the enlarged grain boundaries. This defect is
usually not limited to the surface and may be sub-surface or at interior locations when
associated with heavy mechanical working. Metal with these conditions will be scrapped.
6.10.9 Laminations. A type of discontinuity with separation or weakness generally aligned
parallel to direction of the worked surface of the metal and may be the result of pipe
blisters, seams, inclusions, or segregation elongated and made directional by working.
6.10.10 Linear indication. For nondestructive examination purposes, a linear indication is
evidence of a discontinuity that requires interpretation to determine its significance.