Pop Rivet vs Screw..Which is stronger?

Discussion in 'Materials' started by rebar, May 9, 2012.

  1. Wynand N
    Joined: Oct 2004
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    Wynand N Retired Steelboatbuilder

    I used 6 & 8mm steel rivnuts on my Lotus 7 replica I built and many of the rivnuts was fitted through the 1.2mm aluminum body cladding especially the rear mudguards fitment. These (mudguards) were removed and fitted quite a few times during build process for various reasons and still the rivnuts are completely secured...

    I installed all the rivnuts (about 40) on the Lotus with my homemade contraption. It is just a 5 x 40mm flatbar with one end bend up to "lock" securing spanner. the other end has a 6 & 8mm holes drilled. I have another that is made from 1.6 x 30mm flat strip that works equally well but prefer the thicker unit.
    The way I go about it is to take a 6mm high tensile bolt (40mm long) and screw HT nut onto thread, slip on a single washer and push through the flatbar handle. Turn the rivnut onto the screw from the bottom of flatbar until and this is important the thread of bolt past just through the rivnut.
    Now take a spanner and hold bolt head and let spanner lock itself against the flatbar end thats bent up and start tightening the nut and this will compress the rivnut and you will feel when its secure - it tightens up quite solid. Release the tightening nut and remove bolt from rivnut.

    I used this contraption with success for the last 6 years on boats and other stuff and yet still have to get a loose rivnut.
    Commercial units are only good when you buy top quality ones at a big price medium, but the DIY ones tend to snap often and only like ally rivnuts and not steel ones. Been there done that;)
  2. garyohv
    Joined: May 2012
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    garyohv Junior Member

    You need to spread the load and increase the fasteners:
    Get tie down rings or pad eyes (Al) mounted on a 4 hole plate.
    Cut 3/16-1/4" AL mounting plates 2" bigger than pad plate (1" each side).
    Attach plate to surface with 8 rivets.
    Attach pad to plate with 4 big rivets.
    One should calculate the strength of the 4 big rivets on 1/4" AL and 12 rivets on 1/8", but I estimate over 800 lbs. The weak point may be the pad ring.
  3. rebar
    Joined: Sep 2008
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    rebar Junior Member

    holy thread resurrection

    Hey people.. Its funny because I was searching for information on rivnuts again and came across my old thread..:)

    The tool box stayed put the entire trip.. I know the bouncing around in the trailer is dramatic because my tools were all in disarray after towing 900 miles one way over less than favorable roads. The caster wheels under the tool box bent slightly from the weigh bouncing around..:eek:

    Anyway.. Now I need to install Ancra Tie-down Fittings to secure a customized couch to the wall..:D


    But the location of the Ancra Tie-down Fittings are over two 1/8" 6061 thicknesses, so total of >.25" instead of the 1/8" for the tool box. I say greater than .25" because there might be a small gap between the two layers.

    So I cant decide which SS rivnut I want to use..

    Grip range of .200-.260" or grip range of .260-.320" ?

    And I'm guessing I need a test hole to determine how many turns it takes to mushroom the rivnut correctly with my home made tool..

    Are rivnuts still the fastener I want? Or has something new and improved been released since 2012?

    Thanks again!
  4. SaltOntheBrain
    Joined: Feb 2007
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    SaltOntheBrain Senior Member

    Togglers are a little better than a moly bolt.
    they don't load on the points, they secure in place like a zip-tie, and they require a smaller hole.
    Not sure if they're a fit for this job, but they are a great product.


    Attached Files:

  5. rebar
    Joined: Sep 2008
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    rebar Junior Member

    But the wall I need to fasten to has 2.5" X 3/4" X 1/8" 6061 aluminum studs.
    Meaning the trailer wall is less than 1" thick.

    I found jack nuts which have a nice grip range.. But believe the rivnuts to be stronger.
    Joined: Oct 2002
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    FAST FRED Senior Member

    Look at the sites for home built aircraft , they have pull rivets that are structural.

    What would be the problem with using say 20 rivets rather than a few to reduce the loads to very minor?

  7. rebar
    Joined: Sep 2008
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    rebar Junior Member

    Thanks.. Iv ordered 1/4"-20 stainless rivnuts for the .25" grip range because I need four of them to strap my couch to the wall. The couch isn't top heavy so I can mount the strap locations along the base board.

    But now I need to relocate my 400 pound tool box where the straps pull from points not directly on a wall stud as before. I will use e-track this time and wondered what the strength difference is between rivnuts and pull rivets as they are so much easier to install. But the length of the E-track allows me to use 8 bolts or rivets, instead of four as before. Twice as many.

    So, are pull rivets available with strength comparable to rivnuts and bolts? I guess I need to do more research or continue the plan on mounting the E-track with rivnuts, once again.. :rolleyes:
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