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Crankshaft Pins?

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  • Crankshaft Pins?

    I am curious what material are crankshaft pins made from? Nitrided 4340 ?? I may have to make some. Lucky my friend is a Guru of Centerless Grinding. Thanx Mike

  • #2
    I assume we are talking 2-cycle cranks...snowmobile maybee??? I don't know exactly, but they are weldable, I don't think 4340 would weld without heat treatment after without cracking . The ones I was welding were 800 thundercat cranks that the guy had put some 1200 Pierce cylinders on with a 3-stage nitrous set-up.....would throw the crank out of whack without tigging the pins in the cheeks...He said it ran a best of [email protected] before loosing the motor at a 1000'...not to shabby for coasting the last 300'....It just had a short fuse that's all..also the pins are usuallya little tapered and knurled / splined depending on who mad the motor(yamaha had some with X-hatch some straight ,and some not at all) Good luck , Shawn


    • #3
      God knows what the US spec is but we used to make them out of EN39B.

      Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.


      • #4
        Depnding on what you need you can buy crank pins from various manufactures:

        Just need the od and the length
        (you can order longer and cut )

        see wiseco as an example:
        please visit my webpage:


        • #5
          Some discussion on crankin material here: