Right, They indicate the level of difficulty or complexity or . . . There has been some wordsmithing over the years. A, B and C right? A is pretty easy for most shops. C is difficult. In practice many shops are working beyond C now but. It is worth reading the forward in IPC 2221 which holds the keys to proper use of the standard. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Louis Hart Sent: Thursday, October 30, 2008 11:41 AM To: [log in to unmask] Subject: Re: [TN] IPC 2222 classes Mark, et al, Sorry for a blunder on my part. IPC-2222 uses the term 'Level A', etc, rather than Class. I was just back over in the inspection area and noticed my mistake. Classes seem to be connected to tolerance on mechanical dimensions. Louis -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Woolley, Mark D. (Mark) Sent: Thursday, October 30, 2008 11:13 AM To: [log in to unmask] Subject: Re: [TN] IPC 2222 classes Louis, I haven't looked at IPC-2222 but in IPC-600 and IPC-610 the definition of classes is located in the beginning of the spec, in the introduction. Briefly: Class 1: General consumer electronics. Cosmetic imperfections are allowable, and functionality after assembly is most important item on list. Class2: Communications equipment, business equipment. High performance and reliability are desired, but no one dies if the equipment quits. Class 3: High Reliability, life support, flight systems, reliability is critical. Hope this helps. mark Mark Woolley PTRL Laboratory Avaya, 1300 West 120th Ave, Area 33, Westminster, CO, 80234 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Louis Hart Sent: Thursday, October 30, 2008 7:50 AM To: [log in to unmask] Subject: [TN] IPC 2222 classes TechNetters, looking at IPC-2222, I see references to Class A, Class B, and Class C. I can't find a definition of the 3 classes in the document. Would someone comment on how these classes are assigned or determined? The question arose in the context of looking at a drawing with no dimensional tolerances. I'm asking for tolerances from the customer, but want to do my own homework on the issue. Thanks. Louis Louis Hart Compunetics Monroeville, PA USA [log in to unmask]<mailto:[log in to unmask]> 412-858-1272 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 847-615-7100 ext.2815 -----------------------------------------------------