Thank you Gary Ferrari. You have indeed clarified a few points. Since this stuff is just spreadsheet arithmetic reckon why CAD vendors can't incorporate it into our software? When I create a library part I'd input the lead min/max and it'd calculate my hole and pad size based on what class and level I've selected. Then after placement in a design it would minimize the number of different hole sizes as much as possible based on 2222 table 9-3. Or maybe the library definition would only include lead size and the holes and pads would be calculated in the design. Ain't I lazy? But that's what we have computers for isn't it? George W Uptain, Jr. Austin Product Center of Schlumberger Oilfield Services (512)331-3183 ################################################################ DesignerCouncil 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 DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################