Electroplating of zinc on steel can leave hydrogen embrittlement. That is why many nuts and bolts are "mechanically plated". This is, impact plated with zinc in something like a cement mixer that has glass beads, zinc powder, and a touch of a liquid acid. It is also called "peen plating" as the zinc is "peened" or hammered onto the surface. -----Original Message----- From: Gary Bremer <[log in to unmask]> To: [log in to unmask] Sent: Wed, 29 Apr 2009 6:27 pm Subject: Re: [TN] Plating on screws AIDS.FRMI have had problems with screws that purchasing acquired hat had a zinc platting that caused Hydrogen embrittlement but there was no inc whiskers just a lot of broken screws. Gary Bremer > Date: Wed, 29 Apr 2009 13:45:06 -0700 From: [log in to unmask] Subject: Re: [TN] Plating on screws To: [log in to unmask] What is the logic? Is the layer thin enough that stress is not induced or a by-product? Does it poison the alloy as does the addition of lead to tin? The expected results didn't pan out? Was it do to a twist of fate? Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Dennis Fritz Sent: Wednesday, April 29, 2009 1:34 PM To: [log in to unmask] Subject: Re: [TN] Plating on screws On the "Wednesday Whiskers Call" this morning.? NASA reported that the documents they have seen indicate that galvanized zinc is supposedly immune to zinc whiskers.? Denny -----Original Message----- From: EIMCNews < [log in to unmask]> To: [log in to unmask] Sent: Sun, 26 Apr 2009 4:28 pm Subject: Re: [TN] Plating on screws Denny, Steve, Dave, et al Thanks for all the feedback. I knew, of course, about tin and had heard some things about cadmium years ago but dismissed them because cadmium use was declining for much of everything but government spec'd corrosion requirements. Curious if the zinc whisker propensity is more or less for electroplated vs. galvanized zinc. Anyone know? Roger --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for dditional information, or contact Keach Sasamori at [log in to unmask] or 47-615-7100 ext.2815 ----------------------------------------------------- _________________________________________________________________ ediscover Hotmail®: Get quick friend updates right in your inbox. ttp://windowslive.com/RediscoverHotmail?ocid=TXT_TAGLM_WL_HM_Rediscover_Updates2_042009 -------------------------------------------------- echnet Mail List provided as a service by IPC using LISTSERV 15.0 o unsubscribe, send a message to [log in to unmask] with following text in he BODY (NOT the subject field): SIGNOFF Technet o temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) o receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest earch the archives of previous posts at: http://listserv.ipc.org/archives lease visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for dditional information, or contact Keach Sasamori at [log in to unmask] or 47-615-7100 ext.2815 ---------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 847-615-7100 ext.2815 -----------------------------------------------------