Powerline Hardware P8814 (Millennium Part #527382) is a 5/8 in x 14 in square head machine bolt manufactured to Bellcore Specification 6207 for aerial line construction. The 14 in length through-bolts standard-class wood utility poles for strand attachments, guy hardware, crossarms and messenger brackets. Square head geometry lets a lineman hold the bolt against pole rotation with a wrench while tightening the nut from the opposite side. Hot-dip galvanized coating resists corrosion through decades of weather exposure. Pair with square washers and locknuts and order in bulk, since bolt count on a fiber or joint-use aerial route scales with every framed pole position.