James is correct; the formulas are in there. If memory serves, the formulas are on pp. 11-15 or thereabouts in IPC-SM-782A, published August 1993, and IPC-SM-782A with the amendment published in 1996. (However, if you have only the amendment, which was available as a standalone document, that might explain why the formulas are missing.) Mike Buetow IPC Staff ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################