Expanding plug hole position checking jig for concrete - comprises sheet divided into squares each with section denoting plug positions for different loads

摘要

The jig is for checking the position of holes drilled in concrete to take expanding sockets. It is formed by a supporting sheet on which there is printed a basic grid dividing it into a number of squares whose size depends on permissible intervals for different socket sizes, loads etc. In each square there is a first area where a socket can be inserted to carry its maximum load, a second area for a socket carrying reduced load adjacent to the first and a third area where no sockets may be inserted at all.