The Square-D panels I'm using have a hex nuts that can only be tightened with an hex tool (aka allen key/wrench). There is a 50 lb/ft suggested torque specification for this nut. I have torque wrenches for normal sockets but not for a hex nut.

Wonder if there exists a special torque wrench (or an attachment) to tighten hex nuts?

Thank
-kd

If you have a typical 3/8" drive torque wrench, the socket you need has a fixed Allen wrench attached to a socket, such as shown in the picture. Nothing special, just an attachment not see often.