Two sets of wrenches? How are you going to work on 1953 MGs and other British antiques without Whitworth? Willis 'Cookie' Cooke K5EWJ
________________________________ From: Don Wilhelm <w3...@embarqmail.com> To: Pierfrancesco Caci <p...@tippete.net> Cc: elecraft@mailman.qth.net Sent: Sat, April 9, 2011 7:43:22 AM Subject: Re: [Elecraft] understanding screw sizes Pf, Most of the screws in the K3 are #4, and the thread size is in turns per inch (4-40). These are standard sizes here in the US - no metric size hardware is used in the K3 as far as I know. You have the reference link correct. There is also some #2 hardware used in the K3 - it is the smaller diameter, and has 56 threads per inch (2-56). #6 hardware has a larger diameter and will have 32 threads per inch (6-32) The length of the screw threads will change depending on whether the head is flat or not. For flathead screws, measure the entire length of the screw including the head. For the others, measure from the head to the end of the screw. The washers are designated by the size of the hole. Other dimensions may exist if important, but often just the hole size and the washer type (flat, internal tooth lockwasher, split lockwasher) suffice for the description. Sorry for those in "Metric Land" who do not understand the US hardware system. We tried to go metric many years ago and failed. Most of the auto industry is now metric, but for small hardware, the US sizes predominate here. We have to keep two sets of wrenches if we are to have a complete set. 73, Don W3FPR On 4/9/2011 1:51 AM, Pierfrancesco Caci wrote: > Hello, > while lenght of the screws is given in the manual in mm also, I'm > trying to figure out how to read the screw and washer diameters > that are given as "4-40" and such. Is this the relevant standard? > http://en.wikipedia.org/wiki/Unified_Thread_Standard > > For washers, the first number should be the size of the hole, right? > > Pf > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
