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.