Fastener Distributor FAQs: When To Use a Grade 2 Hex Head Bolt

The hex head bolt holds an important place in the fastener industry. Contractors, OEMs, maintenance staff and many others use hex bolts on a regular basis. Your fastener distributor offers this common fastener in different grades or strengths in order to provide affordable solutions to specific applications and situations. Hex Head Bolt Grades Hex head […]

The hex head bolt holds an important place in the fastener industry. Contractors, OEMs, maintenance staff and many others use hex bolts on a regular basis. Your fastener distributor offers this common fastener in different grades or strengths in order to provide affordable solutions to specific applications and situations.

Hed Head Bolt Grades

Hex head bolts are available in several steel grades, including:

• Grade 2

• Grade 5

• Grade 8

While grade 5 hex bolts, made from medium strength carbon steel and heat treated to provide greater levels of corrosion resistance and strength, are the most commonly used, certain specifications call for grade 8 and grade 2 steel.

A grade 8 hex head bolt is made from a carbon alloy and treated to create the optimum durability. They are used in the aerospace industry, as well as the military and critical mechanical applications. Offering a higher tensile strength than common grade 5 fasteners-150,000 psi from grade 8 compared to 105,000 psi from grade 5-these bolts provide the reliability required in applications involving heavy loads and stress.

When Is a Grade 2 Hex Head Bolt Used?

Grade 2 hex head bolts are made from low to medium strength carbon steel and offer a tensile strength of 60,000 to 74,000 psi, depending on the diameter. Contractors, designers, OEMs and maintenance staff turn to grade 2 steel fasteners for non-critical joints and applications, mainly because of affordability.

Low to mid-grade steel fasteners cost less to produce and in some cases, have a significantly lower price tag than grade 5 or above. Grade 2 makes economical sense when your application calls for hex head bolts in joints that are not exposed to extreme temperatures and excessive stress.

A grade 2 hex head bolt comes with an unmarked head, boasting a smooth, circular top above the hex. They can be partially or fully threaded, depending on your needs, and range in diameter from 1/4" to 1 1/2" and above.

When in doubt, ask your fastener distributor about whether or not a grade 2 hex head bolt will work for your application. Grade 5 and grade 8 will also be available, and may be a more reliable choice depending on the exposure and design.