I don't believe there is a specific spec for what you are looking for...someone please correct me if I am wrong... The IPC-2221 page 55 has an example requirement that says for UNCOATED (no soldermask or conformal coating) boards, you need .75mm minimum but not less than allowed by the electrical clearance requirements... The things that would govern the amount of spacing from any mounting hardware would be voltage on the line in question relative to any voltage or ground potential on the hardware, tooling clearance to swage or mount the standoff, and installation tool (screwdriver?) and hardware clearance from any screws and washers used in mounting the standoff to a chassis or bracket. Also be concerned about clearance to any nearby component body as well as the conductive pattern or any conductive non-insulated lead(s) from the component involved. If you are doing UL or TUV certification, there are more stringent requirements to be concerned about... The ability to prevent shock hazard by not allowing the end user to get their finger or a tool into an area that will get them electrocuted across the line or from the line to ground, spacing between the primary line voltages and SELV or Safety Extra Low Voltage requirements at 48VDC or lower... secondary voltages... Distances from Ground to the line voltages, line to line voltages, and on and on... They are also concerned with Fire hazard... a failure shall not cause a fire hazard... etc... It's a little more complicated... Best regards, Bill Brooks - KG6VVP PCB Design Engineer , C.I.D.+, C.I.I. Tel: (760)597-1500 Ext 3772 Fax: (760)597-1510 e-mail:[log in to unmask] http://www.dtwc.com http://pcbwizards.com -----Original Message----- From: Gary M. Koven [mailto:[log in to unmask]] Sent: Monday, March 28, 2005 10:11 AM To: [log in to unmask] Subject: [DC] Conductive pattern to mechanical hardware clearance Which IPC specification will show the minimum clearance from conductive pattern to mechanical hardware such as swage standoffs? Right now I have approximately 0.025in (0.635mm) from via pad edge to standoff lip edge, and want to make certain that distance will be sufficiently robust for production. The manufacturers' datasheets don't specify a recommended clearance, and neither do the IPC-222X series specs. Thanks, ====================== Gary M. Koven Engineering Services Manager Dynazign, Inc. 806 Tyvola Road, Suite 100 Charlotte, NC 28217 P: 704.405.1234 x210 F: 704.405.1402 http://www.dynazign.com/ ---------------------------------------------------------------------------- ----- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL) Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL) Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------