[Chifo Jr]

For standard types of bolts there is a hash designation on the hex head of the bolt. Count the amount of hash on the head and add two to it to get the grade of bolt. If there is no marks on the top it is a grade 2 bolt. Three marks is a grade 5 and six marks is a grade 8 bolt. Most socket head cap screws are grade 8, unless they are in a different alloy.