Need 3/8" x 26 TPI Flange Nuts

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I don't care for the cap nuts that Shimano uses on their NEXUS gear hub axles. I can find only cheap flange nuts in the proper size, but they will strip in no time on the NEXUS axle. The flat spots on the NEXUS axle are rough on the nuts. I find the kind of flange nut I want in cro-moly in other sizes, but not in 3/8" x 26 TPI. The nut must tolerate being torqued to 45 Nm (33 ft-lbs). Any suggestions where I might be able to find such nuts? I am talking about this type flange nut: I do not want a track nut (which has a rotating washer integrated).
 
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Mori, have you considered using a Nord-Lock or other disc lock washer with a regular nut in place of the flange nuts? It'd give you the same clamping area, and when properly torqued, they rarely come unfastened because they torque load must increase before they will unfasten.
 

moribundman

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 Originally Posted By: MGregoir
Mori, have you considered using a Nord-Lock or other disc lock washer with a regular nut in place of the flange nuts? It'd give you the same clamping area, and when properly torqued, they rarely come unfastened because they torque load must increase before they will unfasten.
It's not a matter of the nut coming loose. It's a matter of the nut surviving the ultra-hard and wicked sharp thread on the axle. The axle threads will work like a tap on most nuts when you torque to spec.
 

moribundman

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 Originally Posted By: tom slick
Never mind I just realized 3/8-26 is a BSC thread.
Aye. I don't know why Shimano went with that oddball... Why cro-moly, you ask. Well, it seems to me the Shimano cap nuts are made of it, and they survive the brutally hard and sharp threads at 45 Nm. The 3/8"x26 nuts that I find online can't be good. They cost between 50 cents and $1 a piece. I see some "top quality" nuts on ebay, but the Brit in question won't sell outside the UK. They aren't flange nuts anyway.
 
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3/8x26 isn't 'oddball'; it was/is THE standard size axle for many years. all BMX (racing bikes, not the jumping/trail bikes that use even larger sizes) are 3/8x26. all solid axle non-coaster brake (which are 3/8x24tpi)rear hubs were 3/8x26. the now more common size of 10x1mm is an offshoot of hollow quick relase axles. check out a good bike shop that uses QBP's (quality bicycle products) expanded parts listing, like this one FWIW, I use a nexus 7 hub on my getaround, and I use the standard shimano supplied nuts, they are nice and burly and pretty too! EDIT: I don't know why, but I went and did the search for you, here
 
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moribundman

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mpvue, the size is oddball for an MTB. None of the techs at the LBS was of any help. They all used the trial-and-error method to determine "fit." Only one tech had a thread pitch gage, and he confirmed that the nut has 26 TPI, which I had already told him. None could determine diameter, which I had already told them. Two techs tried selling me 10 x 1 nuts, because they "fit" on a 3/8 x 26. I have no problem finding 3/8 x 26 flange nuts online, but I have trouble finding good ones. I have used track nuts (the ones with the attached rotating washer) in the right size from the Harris Cyclery. Those nuts were too soft and did not survive the proper torque spec repeatedly. I don't know if their flange nuts are any better. They don't say out of what they are made. Do the Shimano cap nuts look to you like they are made from cro-moly? The main reason that I don't care for the cap nuts is that I need the axle ends uncovered, because I use them as attachment points.
 
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unfortunately, most 'techs' in the LBS don't know much besides what's current. I worked in shops from '86 to at least '05, so I've seen it all. I've never wondered about the strenth of the shimano nuts. I've only had to touch them a handful of times in the last 10 years or so. have you actually stripped out axle nuts? track nuts also? track nuts are stupid durable. no one applies more torque to a pedal than a track racer, so they really hammer on those axle nuts, since a wheel slip can kill them. I will say I never had the need to examine the threads on the nexus hub; maybe there are some burrs that need to be filed down? 33ft/lbs really isn't very much. most all shops won't use a torque wrench on an axle, heck, most don't even own a torque wrench! if there is nothing wrong w/ the axle threads, and you still strip out nuts under 33ft/lbs, you might (I know, hard to believe) be doing something wrong :)
 

moribundman

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Thanks for all the second-guessing. I think all the info is already in what I've posted so far, but I'll gladly repeat it and elaborate: 1. I have not stripped any of the Shimano cap nuts. 2. I have stripped flange and track nuts at 33 ft-lbs when reusing the nuts more than a few times. 3. The Nexus axle is made from an extremely hard steel. The threads are very sharp and practically become a tap. There are no burrs and there is no damage to the threads. The problem is either the low quality of the nuts that I've used, or maybe they sold me 10 x 1 nuts when I ordered 3/8 x 26. After all, a 10 x1 nut will spin easily onto a 3/8 x26 axle. A wheel slip would destroy the shaft drive, since alignment of the meshing gears is critical. A wheel slip would cause the gears to mesh at the wrong angle and to bind.
 
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 Originally Posted By: moribundman
2. I have stripped flange and track nuts at 33 ft-lbs when reusing the nuts more than a few times. 3. The Nexus axle is made from an extremely hard steel. The threads are very sharp and practically become a tap. There are no burrs and there is no damage to the threads. The problem is either the low quality of the nuts that I've used, or maybe they sold me 10 x 1 nuts when I ordered 3/8 x 26. After all, a 10 x1 nut will spin easily onto a 3/8 x26 axle. A wheel slip would destroy the shaft drive, since alignment of the meshing gears is critical. A wheel slip would cause the gears to mesh at the wrong angle and to bind.
I wouldn't think it to matter how 'sharp' the threads are, a proper size nut will not strip @ 33ft/lbs. wheel position is ensured by the special axle locating washers. since I'm SURE you're not overtorqueing (sp?) then perhaps the nuts are oversized.
 

moribundman

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Since the nuts are never marked, it is quite possible that I got the wrong size, which in that case is likely 10 x 1. I have no way of confirming, since the threads are stripped. The techs at bike shops, who you claim to be incompetent at large, are either unable or unwilling to source the proper nuts. I'm not applying too much torque. Until farking around with those axle nuts, I have never stripped any nut on either any of my cars or on any of my bikes. There is one Shimano locking washer (with the little hooked tab) only on the right side. On the left size there is a large washer and a nut. As far as I know, Shimano does not ever use the special locking washer on both sides. There is no provision for a locking washer on the left side.
 

moribundman

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The last place I checked today had those nuts. He claimed to have a big bag of them.
 

moribundman

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These are the different types of axle nuts available. From left to right: track nut with permanently attached rotating washer, flange nut, Shimano cap nut Alright, this is how it looks: On the left side, there's just big washer and an axle flange nut. Shimano uses cap nuts, because they are afraid someone will nick his leg on the bare threads. On the right side, there is the Shimano locking washer that prevents the axle, which is flat on two "sides," from spinning. You can see the locking tab at the bottom of the washer. Normally, there is only a cap nut that goes on the axle. I use a big washer and a flange nut. Unfortunately, the axle doesn't protrude far enough on this side to use it as an attachment point. Oh well, at least I have now the flange nuts, which I prefer very much over the cap nuts.
 
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fancy manhole cover! my setup (traditional chain drive), IIRC, uses the tab washer both sides. what's that bolt for that's right above the word sussex?
 

moribundman

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If the tab washer is used on both sides, how do you adjust the thrust angle? The bolt should be replaced with a rubber plug. It closes a threaded hole that serves no purpose.
 
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no need to adjust the angle; the hub is intended to be used on a bike w/ angled dropouts, so it all wound up in the right place. but, again, I can't be 100% that there is one on the left. FWIW, I'm running a 40+yr old Rudge bike. wheels are vintage fiamme yellow label alloy rims, laced onto the nexus hub, and some sort of large body alloy hub up front. rear wheel is laced radial on the left, 4x on the drive side, and the front wheel is full radial. I opend up the rear dropouts to 135mm, and opened up the slot for the larger than original axle.
 

moribundman

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I looked into it and it appears that at least some, if not most bikes with Shimano geared hubs do indeed use tabbed locking washers on both sides. So you are probably right about two tabbed washers being used. The way the left track end is designed on my bike, it appears as if I could use a white (they are color-coded according to design) Shimano tabbed locking washer there. I'll look into it. I wouldn't be surprised if someone cut a corner in cobbling the bike together. By now there are few original parts on this bike, besides the frame, drive, rear wheel, rear brake, handle bar, and seat pot. Everything else has been replaced.
 
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