5/16-18 x 1 1/4 Carriage Bolt Grade 8 Fully Threaded Plain 1 1/8-7 which means that it is

which means that it is not coated with any additional material

while the Grade 2 rating indicates that it is suitable for general-purpose use

With its strength and corrosion resistance

where the square head helps to prevent the bolt from turning when tightened

This 1/4-28 x 1 1/2 Hex Cap Screw is made of steel and has a Grade 8 rating

5/16-18 x 1 1/4 Carriage Bolt Grade 8 Fully Threaded Plain 1 1/8-7 which means that it is5 16 18 x 1 1 4 Carriage Bolt Grade 8 Fully Threaded Plain: Diameter: 5 16" Thread: 18 threads per inch Length: 1 1 4" Grade: 8 (high strength) Fully threaded Plain finish Used for heavy duty applications in wood or metal