I need some giant double ended wood screws of maybe 10mm or 12mm diameter by 100mm long. (or bigger)
(fixing 5"x5" timber baulks upright to 10" x 5" oak railway sleepers to form a handrail over a bridge). So far I've failed to find a supplier so may have to make them..
So how the heck do you cut a tapered woodscrew thread on a screwcutting lathe???
AWEM