Dave; The IPC design rules have certainly taken this spacing into account. The IPC-D-275 requires that the designers add a "Standard Fabrication Allowance" per table 5-10. This table is intended to allow for variation in the fabrication process. The amount of allowance chosen, should be placed in a note on the master drawing, flagging the amount to the fabricator, inspection, and purchasing. If the inspection allows breakout beyond the incorporated allowance, then there could very well be a spacing violation to the nearest conductor. I mention purchasing, since it is their job to match vendor capabilities with design requirements. No sense sending a job to a fabricator that is beyond his normal capability. Regards, Gary Ferrari IPC Staff *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************