To all, THANK YOU VERY MUCH!!!! I guess I underestimated the good folks here on TechNet, silly me! I am very pleased with the responses and the information. Especially to Dave and Jay. I thought I knew the formula for figuring this out, that is to go from an X-Y coordinate to the diameter, however I don't think I ever heard of a factor to apply (.3535) to the diametric number to go the opposite direction! And I thought this would be outside the realm of TechNet! Next time I will pay attention to the name of the forum!! Richard Hamilton Clemar Mfg. / Rain Bird [log in to unmask] ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################