Torque specifications for fasteners in Aluminum castings
Torque specifications for fasteners in Aluminum castings
(OP)
Hello,
I'm reviewing my company's existing standards for our fastener torque specifications, particularly as they apply to our metric SHCS' in aluminum castings (AA356-T6 material).
I understand that under specific loading conditions, we need to review the bolt torques in detail based on the strength of the materials and the applied loads.
However, in some applications we use brackets that are used to mount sensors and other items to the casting (i.e. there is no special loading, only machine vibration.) In such applications, I'd like to start working with a "general purpose" torque table based on fastener size.
Is anyone aware of a standard or document (I've been looking at Aluminum Association and various other organizations' standards with no luck) that has some recommended torques into aluminum castings? My plan is to use this as a starting point, take a scrapped casting, tap some holes in it and make sure our more experienced assemblers are ok with the torque specs.
Thanks in advance,
I'm reviewing my company's existing standards for our fastener torque specifications, particularly as they apply to our metric SHCS' in aluminum castings (AA356-T6 material).
I understand that under specific loading conditions, we need to review the bolt torques in detail based on the strength of the materials and the applied loads.
However, in some applications we use brackets that are used to mount sensors and other items to the casting (i.e. there is no special loading, only machine vibration.) In such applications, I'd like to start working with a "general purpose" torque table based on fastener size.
Is anyone aware of a standard or document (I've been looking at Aluminum Association and various other organizations' standards with no luck) that has some recommended torques into aluminum castings? My plan is to use this as a starting point, take a scrapped casting, tap some holes in it and make sure our more experienced assemblers are ok with the torque specs.
Thanks in advance,





RE: Torque specifications for fasteners in Aluminum castings
If you want to do it well, then all tapped holes in the casting have a threaded insert.
If you want to prevent damage then you don't tighten the bolts to their optimum torque in the aluminum and you rely on secondary means of retention.
Obviously I recommend the former solution.
RE: Torque specifications for fasteners in Aluminum castings
RE: Torque specifications for fasteners in Aluminum castings
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Torque specifications for fasteners in Aluminum castings
It seems that while 'standard torque tables' are fairly common and well accepted for typical structural fasteners/materials etc. they are hard to come by for less common/typical applications.
Folks here have spent time looking for information for 'non standard' applications and not had much luck.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Torque specifications for fasteners in Aluminum castings
As gadkinsj pointed out, in areas where frequent disassembly/reassembly is required, we use helicoils and have a set of torque requirements for those.
Loctite is also specified where needed, but we cannot spec this in lieu of torque requirements.
Agreed that this is a non-standard application, however our company has heavily adopted the use of aluminum castings, so this will warrant further study with the guys on the floor so that we can start to work towards an "internal" standard.
RE: Torque specifications for fasteners in Aluminum castings
Regards,
Mike
RE: Torque specifications for fasteners in Aluminum castings
RE: Torque specifications for fasteners in Aluminum castings
Just saying
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?