While these two bolts are virtually identical in terms of chemical and physical strengths and properties, there are several differences between the two. The Grade 5 specification falls under the Society of Automotive Engineers (SAE) classification system, while A325 is an ASTM specification. ASTM A325 bolts are more commonly specified by engineers for use in structural steel connections on heavy construction projects, while SAE Grade 5 bolts are more common in OEM-type applications.
Grade 5 bolts are most typically made, and are most readily available in a finished hex bolt configuration. A325 bolts are required to have a heavy hex head. The same thing applies for the compatible nuts. 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 and including 1-1/2″ diameter. For bolts larger than 1-1/2″, ASTM A449 should be specified.
Lastly, the required thread lengths are different. Grade 5 fasteners, like most grades, have a standard thread length of twice the diameter plus 1/4″ for bolt lengths less than or equal to 6″ and twice the diameter plus 1/2″ for bolt lengths 6″ and longer. A325 bolts have specific thread lengths, based on the diameter of the bolt, that are shorter than most other bolt grades.
Is there such a thing as a A325 washer?? If I am using a A325 cap screw and a heavy hex nut, can a grade 5 washer be used??
@Brian- The A325 standard requires an F436 structural washer. Any substitution should be approved by the engineer of record, but F436 washers are very common, so finding the proper size should not be an issue.
What if someone is asking for structural bolts that are 3/8″. Should I use grade 5 in that case though they are asking for structural?
@Edwin- Since there are not any structural grades that include 3/8″, using SAE J429 grade 5 is your most likely alternative, but that should be communicated back to the project engineer.
is grade 8 hex bolts the same stregnth as the structural bolts? I am thinking grade is stronger.
I am correct?
@Patricia- There are two grades of structural bolts, A325 and A490. A490 bolts have a similar tensile and yield requirement as SAE grade 8, but there are still some testing and dimensional differences. A325 structural bolts are not as strong as grade 8 bolts- they are more similar to SAE grade 5 bolts- but still have some testing and dimensional differences.
dear sir
plz tell me about sae grade 5 similar material
viral patel
9537156508
vrl_01@yahoo.co.in
@Viral- Many grades of carbon steel can be used to make SAE grade 5 bolts. If you have a specific question, we’d be happy to help if we can.
Dear sir i want Sea grade 5 list
Vrl_01@yahoo.co.in
@Viral- We do not have a list of available grade 5 bolts. If you have some sizes you are looking for, we’d be happy to look and tell you if they are readily available.
I have a drawing asking for 17-4 threaded rod or grade 5 minimum threaded rod my supplier is offering b7 threaded rod which is heat treated, should this be ok?
@Greg- 17-4, grade 5, and B7 are all very different materials with pros and cons for each. You should consult an engineer familiar with the job in order to find out which is best.