Spindle/Insulator Pin Overhead Line Fittings Power Line Hardware China Pin Insulator with Spindle, Insulator Pin Spindle, Spindle For Pin Insulator, Insulator Pin Specification: Spindle/ insulator pin can be divided into lead head spindle�?nylon head and steel head spindle, and steel head spindle includes small steel head and large steel head. Pin insulator is finished by hot dip galvanize with excellent mechanical strength, usually used with insulator and normally coming with nuts and bolts.