Where to buy 9/16x20tpi nuts?

Does anybody know a good source of 9/16x20tpi nuts? I’m building an ultimate wheel, but having a hard time finding a left-hand-thread nut for the pedal mount. Plenty of places have right-hand ones, but I can’t find a left one from anywhere that isn’t bulk-only (and I don’t really want 1000!)

I found jtrops’ thread about his UW build, but he got round it by using 1/2" thread pedals. I’ve got plenty of spare normal pedals though, so really want to use 9/16.

I thought about cutting the ends off an old pair of cranks and using those as captive nuts, but nuts would be neater (and I haven’t got a spare pair of cranks to cut up at the mo - I short-sightedly sold an old pair of steel cranks a couple of months ago when I was having a clearout :roll_eyes: ).

Oh, and I’m in the UK - but any pointers to possible suppliers would be a start.


Sorry I can’t be more help, but I started to make one last weekend using 1/2" nuts from the local hardware store. I bought a $20 pair of 1/2" pinned platform pedals because I figured it’s easier than trying to find the 9/16" nuts.

That’s probably true - it would be easy enough to buy a pair of cheap 1/2" pedals. But it seems a bit silly when I’ve got a few pairs of spare 9/16" ones lying around.

If (or when) I give up looking for 9/16" left-hand nuts, that’s what I’ll end up doing. Or I might try to pick up a pair of dead cranks from the LBS and use the ends.

I can’t believe it’s so hard to find them though… UDC used to sell UW pedal mount kits that looked like a couple of nuts welded onto metal plates (I can’t remember how expensive they were), but even those seem to have disappeared.

I even thought of getting somebody to cut threads in a couple of lumps of steel for me (my wife works at a place with a big machine shop), but it seems nobody keeps taps for that thread. It seems it’s pretty much unique to bike pedals - I suppose only a machine shop that deals with bike parts would have any reason to have them. Grrr.


I’ve made quite a few UWs in the past. Almost always used old cranks. You end up with a bit more metal to weld to. If you know a bike shop that actually fixes bikes they usually have a box of old cranks ready to go to tip.

It is possible to buy a tap (designed for bike use), usually in a set of one LH and one RH.

www.mcmaster.com has 9/16"-18 LH nuts.

Why do bicycle people insist on doing stuff like this? I measured one of my pedals with a thread gage and, sure enough, it’s 9/16-20, non-standard even for the RH thread. I called a local LH thread specialty company and they said both the 9/16-20 tpi RHT and LHT would have to be special ordered. I wonder if some bike shop would carry a supply of these nuts. I can’t imagine why. The only thing anyone would need one for would be to build a UW. The bike shops may, however, have the taps so they can chase the threads in stripped cranks.

Probably because the bike standard goes back farther than any other “standard.”

I’m thinking that pedal axles that thread into cranks are not that old. And, of them, the 9/16 spindle is very recent. Bicycles probably pre-date standardized threads, though.

Threaded pedals date to at least the 1880s. You’ll probably be interested in Speedplay’s pedal museum, if you haven’t seen it already. (Clipless pedals were invented in 1895, by the way).

Like I said, they’re not that old. Standardization for screw threads began in the early 19th century. I think bicycles date from the same time period, 1800 or so.

Sometimes standards don’t have to be official. Maybe way back then someone was the sole supplier of left hand taps and dies to the bike builders. UDC sort of has a standardizing affect on us.

What are on the high end bikes that have had countless FEA analysis ran on them in order to save weight and stay robust?

If you want to use 9/16" pedals you might want to try pedal extendars instead of nuts. They are more pricey than nuts, but I’ve seen them at bike shops and on eBay. In the end though it might be cheaper and faster to go with 1/2".

Thanks for the replies folks.

I think I’ll just find an old pair of cranks and use the ends instead of nuts.


Do you want steel or ally? I can put either in your BUC parcel for you :slight_smile:


Cool - thanks for that Spencer. Steel would be best please :slight_smile:


All bike pedals I’ve ever seen (as a keen cyclist all my life) are 9/16"x20tpi thead, apart from small children’s bikes and some BMX that use 1/2". There are a few rare exceptions, like that freaky Shimano design (1980s?) that had the pedal platform suspended below the axle line and therefore had a much bigger thread (which I believe was very similar to another much older idea). But anyway, pretty much all pedals on “proper” adult’s bikes from low-end to professional race machines are 9/16"x20.

Unfortunately for us UW builders, it seems like nothing else in the world uses that thread.


An easier but more expensive option would be the GB4 Pedal Inserts from Municycle.com… €35 plus postage from Germany.

I just found lug nuts that are 9/16" x 20tpi. they are right, and left threaded. I think with only a little work these could be used for UW pedal mounts.