Are there any other "high strength" bolts other an A325, A449 or A490? Would SAE Grade 5 and 8 qualify?
The term “high strength” is a somewhat ambiguous fastener term. Most people in the industry would interpret the phrase “high strength” to refer to any bolt that has been quenched and tempered (heat treated) to develop its strength. Additionally, the ASTM specification F1554 Grade 55 is commonly referred to as being manufactured from a “high strength, low alloy steel”, even though this material is not heat treated. Any grades on our Strength Requirements by Grade Chart with a “Q & T” in the Material & Treatment Column undergo heat treatment and would be considered high strength by most people in the fastener industry. Both SAE J429 Grades 5 and 8 have been quenched and tempered and would be considered “high strength” by most.
good day sir i have a question about galvanizing that can v galvanize A490 bolts if no then i have also another question what should we do because we facing bolt fracture these days 1 out of four bolts cracks appreciate your response
@Muhammad- Galvanizing is expressly prohibited for A490 bolts. There are other coatings that are allowed, if a coating is needed. We are unable to diagnose cracking, you will need to contact a metallurgist or lab.
Why hardness cannot be measured in anchor bolts and studs ? Is there any marking required for A36/Grade 4.8 studs/Anchor bolts ?
@Nishad- hardness can be measured, but in most cases it is not required by the product standard, so the test is not performed. The results of tensile and yield testing is typically preferable to hardness. There is no marking required for A36 material, we are not certain about marking for 4.8 bolts since we do not manufacture that grade.
Please let me know high strength bolt must be have grade 10.9 or can be grade 8.8
Thanks your cooperation
@Mohammad- Grades 8.8 and 10.9 are both considered high strength bolts, but 10.9 is higher. Grade 8.8 is similar to SAE grade 5 or ASTM A449, whereas 10.9 is similar to SAE grade 8 or ASTM A354 BD.
Can I use ASME replace SAE bolt ? Same size and length ,I don’t know both type nuts is same or not .
@Luke- There are many grades within ASME as well as SAE, so we’d need to know what grade from each you are wanting to substitute. Regardless, an engineer should always be consulted before any substitutions are made.
good day sir
could you please explain what is actually the different between the regular bolt and hight strength bolt? from the process and the composition commonly. thanks
@Dineta – Low carbon bolts (regular) are made from low carbon, low strength steel, whereas high strength bolts are made from medium carbon or alloy steel and heat treated to achieve their higher strengths. We have summaries of both low carbon (A307) and high strength bolts (A325/A449/A490/A354/F1554) on our website.
Could you send me the bolt pretension torque KN to NM (conversion table)
@Prakash – Apologies, but we do not have a conversion table for those units.
good day sir
could u please give a sample computation for ASTM 325 AND 490 bolt sized M30 minimum tension, kips (kn)
@Velnie – I am sorry, you will need to clarify what information you are looking for. If we can help, we will be happy to do so.