I'd go with the pin gauge any time. Many times I've seen the hole size be good until you got to the bottomside where the platting caused a much smaller hole size that either prevented a press pin operation or a hand insertion prior to wave solder. The angle of the scope and other error factors and eye fatigue would not lend itself well to check hole sizes after plating. John ----- Original Message ----- From: "Louis Hart" <[log in to unmask]> To: [log in to unmask] Sent: Thursday, April 21, 2011 7:24:46 PM Subject: [TN] hole sizes Technetters, here is a real question, to replace the spurious one I just posted by mistake. May I have some comments on measurement of hole sizes in printed circuit boards? For many years, I have been using plug/pin gauges to check hole sizes. I recently noticed that the IPC test method 2.2.7 called for use of a microscope. My opinion is that the plug gauges are fine, and, if anything, better than a microscope, even a good 20X device. A small measurement quality study we did on some 40-100 x microscopes a while back suggested the error in using them is greater than the tolerance of a plug gage. But I don't want to get in trouble for using a non-recognized test method. Thanks for any comments. Louis Hart Compunetics Monroeville, PA USA [log in to unmask]<mailto:[log in to unmask]> 412-858-1272 ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------