The Standard Centring Head provides aid towards the setting of centre lines, establishing accurate angles and marks for butt-ins, location points inside pipes and tanks, laying out keyways, and measuring declivity. The standard head model can be used on 1/2" diameter pipes and up to 4”. This tool consists of a 4" Y-type head attached to an adjustable dial bubble protractor (DSL.) Use a tapping hammer to operate the hardened centring pin.