漏针现象
铸件粗加工

Snag \Snag\, v. t. [imp. & p. p. {Snagged}; p. pr. & vb. n.
{Snagging}.]
1. To cut the snags or branches from, as the stem of a tree;
to hew roughly. [Prov. Eng.] --Halliwell.

2. To injure or destroy, as a steamboat or other vessel, by a
snag, or projecting part of a sunken tree. [U. S.]

3. To catch on a snag [5]

4. (Fig.) To obtain by a quick action, as though by snagging
[3] something passing by; -- often used of an
opportunistic or fortunate action.