How much stronger is grade 8 than Grade 5?

A grade 8 bolt is the highest grade SAE bolt. Grade 8 bolts have a minimum tensile strength of 150,000 PSI. As a comparison, the ASTM A325 bolt is roughly equivalent to the SAE grade 5. A grade 8 bolt would be one that meets ASTM A490 standards.

Which is stronger 8.8 or Grade 5?

Usually a tensile strength in the range of 112,000 to 116,000 PSI. In the metric world (a.k.a. ISO) the most common bolts are marked with an 8.8, 10.9, or 12.9. If there are no head markings at all, they are most likely comparable to the SAE grade 2. The 8.8 is comparable to the SAE Grade 5.

Will Grade 5 bolts rust?

Many other grades exist but are used far less often. Grade 2, 5, and 8 are usually plated with a slightly blue-ish or yellow zinc coating, or are galvanized, to resist corrosion.

What are Grade 5 bolts used for?

These bolts are generally used for non-critical joints and applications. A grade 5 bolt is distinguished by 3 radial lines and promises tensile strengths between 105,000 and 120,000 psi. They are most commonly found in automotive applications.

What are the different grades of bolts?

A. The grade of a bolt indicates the tensile strength of the steel. The higher the number the harder it is. The most common grades are 2, 5 and 8. Grade 2 bolts are made out of mild steel and have no marks on the head, except maybe ‘A 307A’ . Grade 5 bolts are a medium hard bolt and have 3 lines on the head.

What is the metric equivalent of Grade 8?

If we want to approximately compare metric grades to U.S. grades, a metric 8.8 is roughly equivalent to a Grade 5. Grade 10.9 is roughly equal to a Grade 8; and 12.9 is roughly equal to a Grade 9. Metric nuts are marked with a single or double numerical symbol (8, 10 or 12).

What type of steel is a Grade 5 bolt?

Grade 5 bolts are marked with three radial lines on the head of the bolt. The bolt is made of medium carbon steel that is quenched and tempered. In 1/4″ to 1″ bolts the proof load is 85,000 psi.

What is the material for Grade 8 bolt?

Grade 8 bolts are marked with six radial lines on the bolt head. It is made of medium carbon alloy steel that is quenched and tempered. In 1/4″ to 1-1/2″ bolts the proof load is 120,000 psi.