Notice this thing,

enter image description here

for a 30mm ...

enter image description here

What is the tool to tighten that properly?

It would seem to be best if it was a long tube-like thing you slid down from the top and tightened, but, maybe there's a thing that grabs it from the side?

(And, what's that type of bolt known as?!)

  • Interestingly I only learned what a pin wrench is thanks to this fantastic site! diy.stackexchange.com/a/136621/79954 . But this thing is different, a pin wrench does not do the job it seems. – Fattie Nov 23 '18 at 6:22
  • If I only have to do it a couple times the appropriate tools are a vise, a hammer, and two screwdrivers or sturdy metal rods. – Wayfaring Stranger Nov 24 '18 at 1:50
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    Right! No, it needs to be done repeatedly .. – Fattie Nov 24 '18 at 2:42

A hook wrench (as used on bicycles)


enter image description here

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    I have adjustable or jointed ones also that allows for a larger range of nuts , I thought the name was broke spanner, but that's just a Nick name we use at work. – Ed Beal Nov 23 '18 at 15:47
  • A hook wrench !! fantastic ! – Fattie Nov 24 '18 at 2:43
  • "broke spanner" great name :) – Jasen Nov 24 '18 at 4:40
  • @Jasen thanks again. My "thing" there is a "30mm" one. Meaning the exact diameter of the "pole" is 30mm. I guess then the outside diameter of the four-notch bolt is perhaps 35-40 mm. (I'll measure it.) In fact, do you reckon I need a "30" size hook wrench, or do I need a "40" size hook wrench ?! I wonder how they measure that? Again thanks! – Fattie Nov 24 '18 at 6:43
  • not my field of expertise, but I would immagine it's by the outer diameter of the ring-nut so 40. – Jasen Nov 24 '18 at 10:03

It is called a four pin spanner socket. Finding one the correct size may be difficult. I would try a local tool supplier with a liberal return policy so if you select the wrong one you can exchange it. There are standard sizes but I have run into some specialty sizes (correct diameter but wrong pin size) issues. If you are handy with a die grinder you can modify a standard socket by cutting notches it. I have also fabricated one from a standard socket by welding pieces of key stock to the outside of the socket.

  • he has the nut detached in image one, he could take it in to the shop. – Jasen Nov 24 '18 at 4:42

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