With standard double row (4 teeth) indenter crimp tools (i.e., Daniels) on a barrel pin/socket, the tool deforms the barrel into a shape like a square except with indented arcs from each corner (hard to describe easy to sketch). To have a capable joint, requires that the individual strands fill the corners of this "square-like geometry." Tinning would probably hinder this deformation. Dependent upon the lug and crimp tool, you may not achieve this same geometry but the principle is the same. Cross-sectioning can confirm whether a joint made outside the lug mfg recommendations is good or not. Refer to European Cooperation for Space Standardization literature on this subject for more information. You should be able to access it at: http://www.ecss.nl/ -----Original Message----- From: Kasprzak, Bill (sys) USX [mailto:[log in to unmask]] Sent: Friday, May 17, 2002 6:32 AM To: [log in to unmask] Subject: Re: [TN] Crimped connections Stu, I've read all of the responses so far but think they all miss the mark. A crimped connection is designed to "rearrange", for lack of a better word, the strands of wire within a conductor. This "rearrangement" is created when a crimp tool compresses the barrel of the lug so that the internal strands can conform to this compression without breaking the strands. That's why some crimp tools have different settings for different gauge wire. I've seen video of crimped connections where this attachment methodology is actually stronger than soldering the wire to the same lug. Therefore, tinning a wire before crimping defeats the design of what crimping is supposed to do. We crimp wires on a regular basis. We perform pull testing on crimped connections and typically the wire breaks before the crimp pulls out of the pin. Can't get any stronger than that! So, never tin a wire before crimping, again never! However, would I rework the lugs that you have? Assuming something less than class 3, probably not, but it would be the last time I'd allow it Bill Kasprzak Moog Inc. Manufacturing Engineering, Electronics 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 the archives of previous posts at: http://listserv.ipc.org/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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 the archives of previous posts at: http://listserv.ipc.org/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 ---------------------------------------------------------------------------------