Insert a pair of these nut-and bolt pins into adjacent flange holes and tighten to align flanges before connecting two pipes.

Each step on these aligner pins matches common bolt holes on pipe flanges, so they're more precise than conical aligner pins and don’t require nuts. Press the pair of pins into mated flanges to make sure the flanges are aligned.

Often called bull pins, these pins are designed to resist mushrooming caused by repeated pounding.