Chris, Are you saying that if I have a .150 hole in a PCB I should expect a tolerance for location to be about a dia. of .015 (MMC)? Tom Burek Ametek/Dixson Chris Robertson <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 12/15/03 02:00 PM Please respond to Chris Robertson To: [log in to unmask] cc: Subject: Re: [TN] Hole tolerance Doesn't quite work like that. It is dependant upon the manufacturer and the drill size. On average it is about 10% of the drill size rounded with a minimum tolerance. Conventional (everyone) .010" - .003" .030" - .004" .050" - .005" Advanced (roughly 9%, min .002") .010" - .002" .040" - .003" .050" - .004" You will find variations and some that can do even better, but this is my rule of thumb. It is a percentage, similar to the aspect ratio of board thickness to minimum drill size. (not a guru though) Chris Robertson Author "PCB Designer's Reference" [log in to unmask] ISBN: 0130674818 Search for it at www.amazon.com ----- Original Message ----- From: Tom Burek To: [log in to unmask] Sent: Monday, December 15, 2003 2:36 PM Subject: [TN] Hole tolerance Greetings guru's, I have an inquiry into hole location tolerance, especially directed to our many PCB manufacturers listening in. What is the best reasonable tolerance you can expect, world wide, (overseas as well as domestic suppliers), for positional location of plated and unplated holes, without adding addition cost to the circuit board? Expressed in a true position format, would a diameter of 3 mils. be unreasonable? dia. .005? Assume a moderate volume of production. Thank you in advance. Tom Burek Ametek/Dixson --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- [log in to unmask] --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------