Recently, when I was riding my bike, one of the crank arms fell off and I realized that the crank bolt wasn't properly adjusted when I ordered the bike, hence when it fell off, I was able to put the crank arm back in, but the bolt was lost, so I've been searching (bike shops & online) for a new bolt, but I couldn't find it anywhere. The bolt on the other side though displays some sort of details, which displays this:- 28-31ft-lbf 387-428 kgf-cm 38-42 N-m.

Image Below:- enter image description here

  • do you know what the model of the crankset? Commented Jul 23, 2022 at 12:38
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    @LamMunnJun FC-M442/443 Commented Jul 23, 2022 at 13:59
  • Did you try sourcing an Octalink bolt? These seem interchangeable, but I don't have first hand experience to say for sure. For example: aliexpress.com/item/4000027463530.html Commented Jul 23, 2022 at 17:39
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    @Klaster_1Нетвойне I’ve already looked at certain bolts, as I already bought a pair (had 2 Bolts inside the package) they were too small, and then I checked at Halfords shop, and they told me that I must buy a self tapping bolt that would be associated with my bike model, but I don’t exactly know which to buy, and I haven’t checked any octalink bolts, hence don’t have any knowledge about them Commented Jul 23, 2022 at 21:18
  • FYI in my experience if a crank comes off while riding, even once, it is irreparably damaged. You should instead get a new crank and make sure the new one is properly installed. Commented Jul 23, 2022 at 23:20

1 Answer 1


I have never seen a crankset with different specs of bolts on either side.

Since you have one, take it out and visit your Local Bike Shop. Ask the mechanic if they have something like that in their scrag bin / junk drawer.

Expect to pay a few dollars but you'll have a bolt that is rated for the purpose. If you get a matching thread bolt from the hardware store it might not be hard enough for the purpose.

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    I already brought my bike to a local bike shop and they told me that they don't sell those particular bolts and that I must search up and buy self-tapping bolts that are associated with my bike model, but I couldn't find the exact one that I need. Commented Jul 24, 2022 at 22:32
  • @AlekssDzirvinskis find a better bike shop then. Look for one that doesn't sell running shoes.
    – Criggie
    Commented Jul 24, 2022 at 23:10
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    I actually found this and bought it from Amazon, it looks like it will work, hence it’s got the same numbers and letters on the bolt as the one I have on the other bolt on the crank set amazon.co.uk/… Commented Jul 25, 2022 at 15:08

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