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Torque Specs for Bolts/Screws

Discussion in 'General Talk' started by The Dude, Jan 18, 2014.

  1. The Dude

    The Dude Veteran
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    Does anyone know what torque should be applied to the screws when assembling these v-slot parts? I have some 45mm motor mounting bolts(m3)... some m5 tee nuts about 10mm... etc I know this may be a strange question but I paid all this money for a torque wrench so might as well use it and have all those parts locked tight together on the frames and motors.
     
  2. Mark Carew

    Mark Carew OpenBuilds Team
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    That's a good question Dude and I am not completely sure of the answer, but I am interested if you are able to find out. It would be nice to pass it along if someone else has this question down the road.
     
  3. Al Hollaway

    Al Hollaway Well-Known
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    Torque values chart http://www.holo-krome.com/pdf/torquedatachart.pdf
     
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  4. Mark Carew

    Mark Carew OpenBuilds Team
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    Thanks Al
     
  5. The Dude

    The Dude Veteran
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    Are the tee nuts steel? Are these torque ratings the max for the screws? Isn't there going to be deformation of the aluminum if you overtighten steel screws? Some of the screws go directly into the aluminium so they may strip if overtightened...
     
  6. Al Hollaway

    Al Hollaway Well-Known
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    Valid points.
    New chart http://www.enfieldmotorcycles.com/forum/index.php?topic=10638.0

    IMO it's more likely you would strip threads by over torque than to deform the extrusion. YMMV.
     
  7. The Dude

    The Dude Veteran
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    Thank you! That's awesome. I'll post the data here in case that site goes down. Screw Torque ratings.jpg
     
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  8. joe.carson

    joe.carson Well-Known
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  9. Joe Santarsiero

    Joe Santarsiero OB addict
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    Nice find.

    EDIT: Note that the recommended torque is the recommended torque for a minimum engagement of 1.5 times nominal bolt diameter. If your engagement length is less than 1.5 times the nom. dia. then do not use the recommended torque provided.
     
    #9 Joe Santarsiero, May 3, 2015
    Last edited: May 3, 2015
  10. joe.carson

    joe.carson Well-Known
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    Hi Joe,
    thanks for your hint! If I understand right you can define the length of engagement and the material under "Mating Thread Data".
    Do you think that the results calculated for a length of engagement of less than the nominal bolt diameter are not accurate?
     
  11. Joe Santarsiero

    Joe Santarsiero OB addict
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    When you input a value less than 1.5times the bolt diameter you will get the same value as 1.5 times the bolt diameter.
    If you torqued to those figures there is a greater likelihood of thread tear out the thinner you go.
     
  12. Joe Santarsiero

    Joe Santarsiero OB addict
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    Here is an example:
    Same bolt. Different depths. The first is at .250 depth and there is a warning.
    The second is at the minimum recommended engagement depth. No warning. Same exact figures.
    Warning! It is highly recommended that a bolt's engagement length be at least 1.5 times its diameter.
    Application Data
    Major Bolt Diameter: 0.250 in
    Bolt Thread Pitch: 20
    Bolt Proof Strength: 44000 psi
    Recepticle Length: .250 in
    Recepticle Strength: 40000 psi
    Applied Tensile Load: 0 lb
    k Factor: 0.2

    Recommended Torque
    43.75 in-lb
    (3.646 ft-lb)
    (4.944 N-m)
    Resultant Tension:875.1 lb
    Maximum Torque
    58.34 in-lb
    (4.862 ft-lb)
    (6.592 N-m)
    Resultant Tension:1166.8 lb





    Application Data
    Major Bolt Diameter: 0.250 in
    Bolt Thread Pitch: 20
    Bolt Proof Strength: 44000 psi
    Recepticle Length: 0.375 in
    Recepticle Strength: 40000 psi
    Applied Tensile Load: 0 lb
    k Factor: 0.2

    Recommended Torque
    43.75 in-lb
    (3.646 ft-lb)
    (4.944 N-m)
    Resultant Tension:875.1 lb
    Maximum Torque
    58.34 in-lb
    (4.862 ft-lb)
    (6.592 N-m)
    Resultant Tension:1166.8 lb
     
  13. joe.carson

    joe.carson Well-Known
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    Thanks for the explanation, now I got it!

    Joe
     
  14. fonebone83

    fonebone83 Well-Known
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    GrayUK likes this.

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