Terry, be aware that the correct amount of torque is determined as much by the objects being fastened by the screw as it is by the strength of the screw.
In some places, a screw threads into soft plastic. Any extra movement beyond the point at which the head touches the surface will strip the threads out of the plastic. In other places screws secure plastic bezels to a panel. These can take a little more torque than the screw-into-plastic situation but not much before the plastic cracks or deforms. And in some situations the screw threads into fairly thin sheet metal with a threaded hole which makes it very easy to strip the threads. The Elecraft manuals provide guidance in the steps where the above occur, but they also presume you are using a manual screwdriver and paying close attention to the feel of the screw as it tightens. Even where the only concern is to keep the screw from breaking, there is little gain from tightening the screw past the point where you feel the resistance suddenly increase. At that point the screw has stretched slightly, clamping the parts together. Lock washers are called for wherever it is likely a screw will work loose. You only need to tighten a screw with a lock washer until the lock washer is compressed, whether it is a split ring or a star type. Squeezing the lock washer past the point at which it is flat does nothing at all and may actually be counter-productive. The amount of torque required depends upon the type of lock washer more than the screw. 73, Ron AC7AC -----Original Message----- 2. are there recommended torque settings for fasteners? I typically use torque limiting drivers that are set as follows for metal fasteners: 2-56 threads = 2 in-lbs 4-40 threads = 3 to 5 in-lbs 6-32 threads = 6 to 10 in-lbs 8-32 threads = 15 to 20 in-lbs 10-32 threads = 25 to 30 in-lbs ok? not ok? Regards - Terry ps: anyone know what power connector is used on the KX3? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
