Peter, That question is essentially unanswerable in this format. The torque required to keep a fastener in place is a function of the material properties of the fastening system and the shock and vibration loads that system will see. You really need to see a mechanical engineering structural analyst to get the answer you need. Michael Hiteshew Lockheed Martin NE&SS Marine Systems 410-682-1259 -----Original Message----- From: peter lee [mailto:[log in to unmask]] Sent: Wednesday, February 06, 2002 2:34 PM To: [log in to unmask] Subject: [TN] Torque requirement Hello, Can anyone provide some general guidelines on the torque requirement for mounting and fastening common hardware onto FR4 materials with threaded steel fasteners, lock washers and bolts? Any table with starting values for common sizes and screw types would be greatly appreciated. Rgds, Peter --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------