From: sgi!pwcs.StPaul.GOV!phile@EDDIE.MIT.EDU (Philip J Ethier) Date: Mon, 14 May 90 9:57:44 CDT To: alliant!alliant.com!british-cars@EDDIE.MIT.EDU cc: pyramid!pyramid.pyramid.com!phile@EDDIE.MIT.EDU Subject: Whitworth OK, here is the official skinny on Whitworth. Source: Machinery's Handbook, 20th edition. Have you ever seen a machinist"s toolbox? There is a deep drawer in the center top. It has a silver-dollar-sized hole in the bottom. This drawer is made to the dimensions of this book. The hole is for you to stick your finger up through to push the book up so you can get it out. Some of you will think this is a gag, but I am confident that there are plenty of you that know it is perfectly true. Anyway, I suddenly remembered that I have such a box and such a book. Strictly speaking, only the coarse threads are British Standard Whitworth, the same diameters and wrench sizes are used in British Standard Fine. Here is a small portion of the chart. Don't forget that the wrench is called by the bolt diameter, not the actual wrench opening. Bolt Diameter Across hex flats maximum minimum 1/4 .445 .438 5/16 .525 .518 3/8 .600 .592 7/16 .710 .702 1/2 .820 .812 9/16 .920 .912 5/8 1.010 1.000 3/4 1.200 1.190 All dimensions are in inches. A 5/15 Whitworth wrench will work for the fill plug on the Armstrong lever shocks on the front of a Spridget. This plug is a 5/16-22-BSF bolt. The wrench will also work for a bolt of 5/16-18-BSW. If there is such a thing as a regular inch wrench of 17/32, that should work OK, as 17/32 = .531, but my local tool supplier says not to hold my breath for that. I think I am going to order a 5/16 Whitworth combination wrench from Moss. There does not seem to be a point to ordering a whole set, as most folks tell me you don't find Whitworth on Spridgets. Guess they didn't have to fill the front shocks! phile@pwcs.stpaul.gov -- Login name: phile In real life: Philip J Ethier Phone: 298-5324