I feel the generally accepted industry standard for the determination of PAD SIZE is the following: NOMINAL Finished Holes Size + (2 x annular ring requirement) + .010" (manufacturing tolerance) = Pad size. Example: .035 FHS + .004 - .001 = NOMINAL Finished Hole Size = .0365" + (2 x .002) + .010 = .0505". I have not read 55110 for a while so just determine what the annular ring is and plug it in. Hope it helps. ################################################################ 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 ################################################################