UNC Hex Head Flange Bolts with Serrations in Bright Zinc Plated (BZP) USA Grade 5 High Tensile Steel
Hexagon headed bolt with a flange. Also known as a washer bolt. The wider surface area beneath the head spreads the clamping pressure and negates the need for a washer.
These UNC hex head flange bolts are serrated. The serrations are anti-rotational and bite into the material which they are connecting to secure the fixing.