M5 stainless fastener deformation

Discussion in 'Bike trends, tech, and industry' started by Markopolo, Jan 12, 2018 at 2:03 PM.

  1. Markopolo

    Markopolo Member

    Thought I should pass this along. Noticed the other day the M5 stainless allen fastener that is used on the chain stay bracket to hold the BB in place had deformed. Because the aluminum bracket that holds the fastener deforms when it is pulled down, or there is no support on the outer portion, the fastener had taken on this deformation also. This is using 5# of torque and the fastener is rated for 8#. The ungraded stainless fasteners are rated for 70k psi which is just a little better then a sheer bolt. My solution is to use the black oxide allen bolt which is significantly stronger but doesn't provide the corrosion protection, but as I don't live near the ocean not a real concern yet. hth.
  2. mzweili

    mzweili Guru

    Could you make a picture of it? It would help to understand the problem.

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