Hey, thanks Russ. I thought this would be a refresher for me. In fact, I picked up 2 things I didn't know: the number after the decimal for metrics, and that inch threads were incremented by 13 thou per size. i.e. a number 10 screw is .026" larger than a number 8. I knew the rough sizes for #4,#6,#8,#10, but not the theory behind it. Now, ask me in a couple of weeks and I might not remember these things.
For cross-headed screws that look like Phillips, I am aware of 3 different styles that look virtually identical. The ones with no marking on the head, are Phillips head screws. The ones with 4 small radial tick marks between each of the 4 slots are PoziDriv, and the ones with a single dot between two of the 4 slots are made to JIS standards. Each have their own screwdrivers required. For instance, there are no Philips screws in any MG. They are all Pozidriv. this is why many of these cars have cross head screws that are bunged up. The American POs used Phillips screwdrivers when working on them. Japanese motorcycles (and sewing machines) used JIS screws. Same thing goes for those bunged up screw heads.
_________________
Chuck.
“Any suspension will work if you don’t let it.” - Colin Chapman
Visit my ongoing MGB Rustoration log:
over HEREOr my Wankel powered Locost log :
over HEREAnd don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766