Dave - The AA portion specifies the thickness tolerance class of the material (first character) and surface quality (second character) the requirements are in sections 3.8.4.2 and 3.8.3 respectively. Class A is the least stringent in both cases. The 3 does not appear to be part of the standard definitions under 4101. Jeffrey A McGlaughlin, CID Engineering Designer/EAS Room 4-2-50 Phone (614)424-7582 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Dave Connitt Sent: Wednesday, May 20, 2009 6:47 AM To: [log in to unmask] Subject: [TN] IPC-4101 specification question Hi all, I have an older fabrication drawing here that has a suffix on a material spec. that I cannot locate in the IPC spec and I was wondering if anybody can help me out. The material callout is "IPC-4101/24-C1/C1AA3. What is AA3 referring to?? Thanks, Dave Connitt CID+ Printed Circuit Designer L3 Fuzing & Ordnance Systems A Wholly Owned Subsidiary of: L3 Communications 3975 McMann Road Cincinnati, Ohio 45245 Ph. 513- 943-2010 Fax 513-943-2288 --------------------------------------------------- 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 -----------------------------------------------------