Is SEMS Taboo - NCRS Discussion Boards

Is SEMS Taboo

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Larry M.
    Very Frequent User
    • January 1, 2002
    • 535

    Is SEMS Taboo

    Is it wrong to believe that SEMS bolts were used as below on a Nov 63 car?

    Looking under my dash at the steering column mounting, hood release mounting and parking brake mounting I found 5 SEMS 5/16-18 X 3/4 black phosphate indented head captured conical washer about 3/4 dia...same basically as a 3846202 used on the female hood catch. The sixth of six was E stamp 7/8 long with a serrated washer...a real 3847758 with no paint or rust. All six look too good to be 50+ years old and I "assumed" they had to have been replaced but the one serrated has to be 50+ or NOS; they are extremely hard to find/buy unless you get used. Then I looked at the screw holding the dash brace, item 2, AIM 1AsmB1.00, which is secured to the dash cross brace by item 6, a 3846202. It is rusted and has body color paint overspray as does the cross brace but no wrench mark...and IT IS SEMS. I'd bet a lot it has been there since the paint/assembly line. Hence, my lead question.

    My lower hood hinge bolts, 3847758 with serrated washers have been replated bright (zinc or cad), which is wrong by all prior information, But my female hood latch and outer splash shield bolts (spec'd as 3846202) are SEMS and are also bright and may have been plated wrong at the same time. So, same question: is SEMS wrong or is it just the plating that is wrong. Could the parts bins have had SEMS in them as a trial ordered by the hardware buyer for the 3846202 on a day in late Nov 63.

    I'd appreciate any philosophy or, better yet, experience in this area.
  • Edward J.
    Extremely Frequent Poster
    • September 15, 2008
    • 6940

    #2
    Re: Is SEMS Taboo

    Larry, I can tell you that all the bolts in the positions you speak off are the serrated washer style bolts on my 63 and believe most are the E head mark's. I know that the Sem's head mark is era correct for 63. But have not seen any 63's with the Sem's with smooth washers at those locations in a 63 before. 64 they went to the smooth washers for many locations.

    Larry, I should add that the serrated washer head bolts always leave a washer impression when tightened, check for those at the bolt locations that have the Sems that will be the tell tell signs.
    New England chapter member, 63 Convert. 327/340- Chapter/Regional/national Top Flight, 72 coupe- chapter and regional Top Flight.

    Comment

    • Michael G.
      Extremely Frequent Poster
      • November 12, 2008
      • 2155

      #3
      Re: Is SEMS Taboo

      "SEMS" is a type of fastener, in essence, a bolt or screw with the washer captured under the head. It originated in the 1930's. It was a trademarked name, not a head marking, though it may have been stamped on some heads to designate the trademark. Today SEMS-type parts are supplied by most companies, but in 1963 I think it was mostly made made by ITW Shakeproof.

      There were some SEMS-type parts on GM cars in 1963, but not many. I believe the Corvette may have had a few, but I can't say where they were.

      Comment

      • Larry M.
        Very Frequent User
        • January 1, 2002
        • 535

        #4
        Re: Is SEMS Taboo

        I may sound naive but I don't actually hold any hope that someone will "bless" SEMS in all the places I have them and I'm speaking of the SEMS headmark. I will change many of them but I still believe that the one on the dash brace may be original. It has a twin brother just above which goes in from the top so i can't see it. I will pull that one just to see. Also, the dash braces were there before paint whereas the others came later so there were multiple parts bins in play. Having said that, Rich Pasqualone (NCRS: Originalcorvette on ebay), who is quite knowledgeable on these topics lists many SEMS for midyears, notably the rear brake crossover line clamp for 63; however, I think this is more prevalent in later years. He shows at least three different washers, star, lock and conical...maybe more. And I found two more on my car today, SEMS with external tooth washer, holding the spark plug wires lower bracket....easy to see on my car since I have no shielding. Is is the same configuration as the 63 bolt I mention above although likely shorter. In any case, what I was hoping was that I'd get a 63/64 guy to tell me he has some original SEMS. 65 and up would not mean validation.

        Separately, I'd like to ask Edward for more info since I don't have 63 facts. What part number was the serrated washer bolt you reference for 63? Was it the3816170? In 64, of the eight places the 3847758 is used, five replaced the 3816170 during the model year so I assume the 6170 had serrations. My car predates two of these changes so I might have 6170s and not 7758s for seat and door hinge mounting.

        Comment

        • Edward J.
          Extremely Frequent Poster
          • September 15, 2008
          • 6940

          #5
          Re: Is SEMS Taboo

          Larry, As for the part numbers i have no book on what is what for which position, But I have restored my 63 and held every nut and bolt in my hand and inspected Sems locations on my 63 I found that the ignition shielding had a sem or two, rear access panel's had sems with a star, washers, and lower rocker panels had sems. they were self tapping with washer a fixed.I will take a look at my e/brake handle and hood later and report back, but I have a funny feeling they were the typical E marks w/serrated washers.
          New England chapter member, 63 Convert. 327/340- Chapter/Regional/national Top Flight, 72 coupe- chapter and regional Top Flight.

          Comment

          Working...

          Debug Information

          Searching...Please wait.
          An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

          Please push the back button and reload the previous window.'
          An unexpected error was returned: 'Your submission could not be processed because the token has expired.

          Please push the back button and reload the previous window.'
          An internal error has occurred and the module cannot be displayed.
          There are no results that meet this criteria.
          Search Result for "|||"