Tick chisel chisel should be preceded by small-scale trial, supervision should be checked, requires the construction side to gain experience before formal tick chisel work.
Before the chisel should be carried out small-scale test chisel, supervision should be inspected, require the construction party to gain experience before carrying out formal chisel ingy.
Before chiseling, small-scale trial chiseling shall be carried out first, and the supervisor shall carry out inspection, and the formal chiseling work shall be carried out after the construction party obtains experience.<br>