When to use fixed or floating blind nuts?

Discussion in 'Steen Skybolt' started by Dances_with_cumulus, Sep 14, 2018.

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  1. Sep 14, 2018 #1

    Dances_with_cumulus

    Dances_with_cumulus

    Dances_with_cumulus

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    i have drilled 1/8th inch holes and have all sheet metal panels cut and held in place with Clecos. Now I have a choice to make- which blind nuts to install. Is there a rule of thumb for where floating versus fixed blind nuts should be used? For example should one type be used where there are no overlapping panels and another where there is? When the clecos are removed and drilled out for the actual screw, the bit will seek to center itself in a rigid blind nut, which will bias the hole to where it should be. That self centering may be less likely if a floating nut is used because the bit tip can wander. Suggestions appreciated! Thanks
     
  2. Sep 14, 2018 #2

    cwilliamrose

    cwilliamrose

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    People swear by the floating blind nuts but I have never used them. I use fixed ones everywhere. The holes in the panels are clearance holes anyway so small errors are not a problem. I might consider using floating style if I was dimpling the panels for flat head screws since they are centered by the dimple and small errors in positioning could become visible.
     
  3. Sep 14, 2018 #3

    Dennis Flamini

    Dennis Flamini

    Dennis Flamini

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    i hate the floating ones when trying to start a screw on the vertical or sloped bulkheads.
     
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  4. Sep 14, 2018 #4

    Neil

    Neil

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    Never use the floaters if I can help it. Never, ever on a vertical surface.
     
  5. Sep 15, 2018 #5

    Dave Baxter

    Dave Baxter

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    I'm with Neil, I prefer the fixed ones as well. Dave
     
  6. Sep 15, 2018 #6

    TFF1

    TFF1

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    Nothing worse than busting out the floating piece with the screw still in place.
     
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  7. Sep 15, 2018 #7

    cvairwerks

    cvairwerks

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    Only times we use fixed nut plates is where there is no clearance available in the structure or when the location requires no possible movement. In all the hundreds of thousands of nut plates I've installed over the years, I can only remember dealing with a couple of them (fixed or floating) that had sheared rivets. Glued on ones are another story.
     
  8. Sep 15, 2018 #8

    taff

    taff

    taff

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    I have installed a mixture, fixed and floating nut plates.
    I found it's easier to line up and have all screws meet their respective nut threads with floaters.

    If it's something small (only a couple of nuts) then fixed is good and I add a wider tolerance to the screw hole.
    It sucks, but I have elongated a hole or two of the attached piece when using fixed plates.

    I'm nuts for using whatever floats your boat (and whatever I have immediately available ;))

    Nut plates are tough on the SS screw thread. I've started to smear (rub) a little bees wax on the screw thread before installing.
    I have found that binding is not so much of an issue.
     
    John Beck likes this.
  9. Sep 15, 2018 #9

    TFF1

    TFF1

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    I don't think I have had rivets shear, just the floater break out. Especially one that has not been apart before off a production line. They will ram that screw in so they don't have to take their stuff apart and fix it. I pre run screws in and stuff so it's not so tight on our little stuff. Big difference if you work in a factory vs homebuilding.
     
  10. Sep 16, 2018 #10

    EAABipe40FF

    EAABipe40FF

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    I think the only ones I've ever cross-threaded were floaters. Yes tough on SS screws. I'll use a tap to remove some but not all of the "lock" and also lube floaters I inherit. I never use them myself
     

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