We have taken similar steps as you have noted for the same reasons. We use 222 all over the place in our mechanical assemblies. Has kept our loose hardware issues to a very small problem. Randy Bock Sr. Quality Manager Pitney Bowes AddressRight Printers (p) 203 720-3861 (f) 203 729-5397 (email) [log in to unmask] "Croslin, Robert" <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 07/01/2004 08:59 AM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to "Croslin, Robert" <[log in to unmask]> To [log in to unmask] cc Subject Re: [TN] Max. Torque applied to a screw securing a PCB Marius, I asked my mechanical engineer and he searched through his files only to find a copy of a post made on 6/11/02 by TechNet's own Phil Nutting that contained the information below. Phil referenced SAE ARP 1928 and noted plenty of variables like assuming the screw was steel or stainless, noting that brass should be lower and nylon lower still. 2-56 - 3 inlb 4-40 - 8 inlb 6-32 - 10 inlb 8-32 - 20 inlb 10-32 - 32 inlb 1/4-20 - 60 inlb. We used to try to lock our boards down using torque specs but stopped. It will differ if you're tightening onto a copper surface, HASL surface, or just plain FR4. Years ago we went to the use of Loctite 222 (threads only) and our problems with loose hardware disappeared. The major problem wasn't the eventual use of the devices, but the vibrations caused in shipping and the resonances caused by traveling in trucks like UPS or FedEx. Hope this helps Bob Croslin Nielsen Media Research -----Original Message----- From: Marius S [mailto:[log in to unmask]] Sent: Wednesday, June 30, 2004 8:20 PM To: [log in to unmask] Subject: [TN] Max. Torque applied to a screw securing a PCB Hello All, I'd like to find out what is the maximum torque that can be appled to a metal screw that secures a PCB to a metal chassis. Perhaps someone can point me to a standards/IPC document on the subject. With many thanks, Marius __________________________________ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------