How do you center the throat to the heel width, on pipe insulation, when laying out measures for cutting a miter?

• A. Align to top edge
• B. Start with center line
• C. Align to bottom edge
• D. Use the outer edge as reference

Answer: (B)

Center line is the reference you need because the cut must be balanced around the pipe’s axis. By starting from the center line, you place the throat and heel widths symmetrically, so the miter cut sits evenly on both sides. This creates a neat, flush joint that wraps around the pipe with proper sealing. If you align to a top or bottom edge, or use the outer edge as a reference, the cut would bias toward one side, producing an off-center throat, gaps, and a poor fit. So, begin with the center line and lay out equal distances on either side to form the miter.