Square nuts (J8563) have always been considered safest to use by utility linemen because of their large wrenching surface. Regular nuts are used on all types of threaded bolts and insulator pins, while heavy nuts are used exclusively on anchor rods.

MacLean Power square nuts are manufactured in accordance with American National Standards Institute Specifications B18.2.2 and tapped Unified National Coarse Threads Series Class 2B after centrifugal hot dip galvanizing, oversize for galvanized bolts and rods.