1. Flux residues between the wires above the tinned length or under insulation could cause corrosion 2. Under pressure from the crimp, the solder will cold-flow and will continue flowing for days, weeks and months to come. This may break the integrity of the electrical connection and it may even flow to where the metals are oxidised. Brian On 31/05/2011 20:24, Gregg Owens wrote: > Dear Technetters: > > I have been posed a question I can't answer. In both the IPC-A-610 and IPC-A-620 require that stranded wires used for crimp connections NOT be pre-tinned with solder. Okay I get the requirement, but does anyone know why this is a requirement. Pre-tinning keeps the strands together, so there is some push-pack on why this is a requirement. Any thought appreciated. > > Gregg Owens > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 16.0 > 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 > For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 > ----------------------------------------------------- > ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------