I purchased an electric tricycle for my sister, but the wheel base is a little narrow, so I want to extend the rear axle. I need a pair of M10 x 120mm matched bolts, one right hand and one left hand threaded. The right hand bolt is not really a problem. I can easily get it in just about any head style and material grade I want. The problem is the left hand threaded bolt. I have been searching, and so far haven't been able to get a left hand threaded M10 bolt that long. One possibility, of course, is to get a bolt blank and thread it manually. The only catch there is my lathe will not do left hand threads. I have also been having trouble finding even a 120mm bolt blank. Does anyone out there have a source for an M10 x 120mm bolt blank, and would someone be able to thread it? I am not too picky about the head style, although the existing hardware is all socket screws, so an Allen head socket bolt would be nice, but a hex head or flange bolt would be just fine. It would also be nice if the bolt were a bit stronger than mild steel, perhaps 10.9 or 12.9. The bolt does not need to be fully threaded. A thread depth of 20mm is more than plenty.