I want to attach a rear basket to my bicycle and I don't know a thing about nuts/bolts. I got a plastic bag full of nuts, bolts, washers, and what I believe (according to what I could find on the internet) are internal star lock washers.

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Is the configuration on the attached photo correct? First the smooth washer, then the jagged star lock washer, then the covered nut? And, the internal star lock washers are smooth on one side and jagged on the other. Which side should face up towards the bolt head?

2 Answers 2


The jagged side should be to the bolt nut, not the washer. You're trying to prevent the bolt nut from turning, thus unscrewing. The jagged side will, to a small degree, bite into the metal of the bolt to increase the holding power. (The majority of the holding power is from just the compression of the lock washer.) Turned the other way will work, just not quite as well. (you don't really care about the washer turning.)

Edit: correct my stupid mistake!

  • Oh, so I've put it together wrong? The jagged-edged ring (the star lock washer) should go in the bolt FIRST followed by the smooth washer, then finally the (screw) nut?
    – girapola
    May 22, 2014 at 20:42
  • The way it is in the picture face the jagged end towards the nut. Leave everything else in the same configuration as the picture. May 22, 2014 at 21:53

Ultimately, as you tighten down the nut, the washer (that's an EXTERNAL star washer in the photo, by the way) will distort and its teeth will grip both surfaces. The manufacturer just got lazy and didn't make it flat, with the teeth splaying out on both sides.

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