US Bolt Head Wrench Size

Head and Wench Size

Bolt DiameterHex/Lag/Square BoltHeavy Hex Bolt
#61/4″
#81/4″
#105/16″
#125/16″
1/4″7/16″ or 3/8″
5/16″1/2″
3/8″9/16″
7/16″5/8″
1/2″3/4″7/8″
9/16″13/16″
5/8″15/16″1-1/16″
3/4″1-1/8″1-1/4″
7/8″1-5/16″1-7/16″
1″1-1/2″1-5/8″
1-1/8″1-11/16″1-3/4″
1-1/4″1-7/8″2″