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.
Are Grade 8 bolts or Grade 5 shear easier?
There exists an often quoted myth, that Grade 5 bolts are better in shear than Grade 8 since they will bend before breaking. Not true. Shear strength of alloy steel is approximately 60% of its ultimate tensile strength. The Grade 5 bolt will therefore always fail first whether in tension or shear.
Can you use Grade 5 nuts on Grade 8 bolts?
Yes, but nuts and bolts have very different failure mechanisms. With Grade 5, A325 and metric 8.8 bolts, low strength nuts can be safely used unless the code prohibits them. With the stronger Grade 8, A490 and metric 10.9, high strength nuts have to be used and these bolts can strip the threads out of mild steel nuts.
Are Grade 8 bolts better than Grade 5?
Grade 8 bolts have been hardened more than grade 5 bolts. Thus they are stronger and are used in demanding applications such as automotive suspensions.
Are Grade 5 bolts rust proof?
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.
Are higher grade bolts more brittle?
Replacing a bolt with a stronger one is not always safe. Harder bolts tend to be more brittle and may fail in specific applications.
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.
How much weight can a Grade 5 bolt hold?
Proof Load
| Nom Bolt Size (in) | Grade | |
|---|---|---|
| 2 | 5 | |
| 5/16 | 2900 | 4450 |
| 3/8 | 4250 | 6600 |
| 7/16 | 5850 | 9050 |
What is a Grade 5 Hex Bolt?
A Grade 5 hex bolt has greater tensile strength than a Grade 2 hex bolt, and its yield to tensile ratio is the lowest of all heat treated steels. The length of a hex bolt is determined by measuring from under the head of the bolt to the base of the threads.
What is SAE grade 5 bolt?
Grade 5 bolts are a medium hard bolt and have 3 lines on the head. Grade 8 bolts are made out of alloy steel and heat treated to a real high tensile. Grade 8 bolts have 6 lines on the head. The specification number SAE J429 is the standard that covers these grades, and many other grades that are not as commercially available as these three are.
Are Grade 8 bolts more brittle than Grade 5?
It is true that grade 8 bolts are more brittle than grade 5. In general (although not always the case), steels that have a higher strength are less ductile . Grade 8 bolts have a higher strength and, therefore, would require fewer bolts in a joint than grade 5.
What is a Grade 5 nut?
Grade 5 nuts are a finished hex pattern, and A194-2H or A563-DH heavy hex nuts are required for use with A325 bolts. Another difference is that Grade 5 bolts may be specified from 1/4″ diameter up to and including 1-1/2″ diameter. The A325 specification covers bolts from 1/2″ up to…