What size nut goes onto a typical US passenger tire Schrader valve? (2023 Update)

Steve W. wrote on Wed, 07 Dec 2016 04:08:41 -0500:

Thank you for that advice as it's not obvious that the tiny $2 four-way tool is good enough considering my searches found a bunch of tools for removing and replacing automotive tubeless tire valve stems from a. Cable pullers b. Grooved hinged levers c. Hook-and-funnel tools (these work without breaking the bead though) d. And the inexpensive 4-way tool

I have the rubber and brass style but is it different for the style that has metal nuts or similar?

Reply to
Leon Schneider
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Scott Dorsey wrote on 6 Dec 2016 16:45:21 -0500:

I keep seeing this *mix* of metric and what they seem to call "Imperial", (which I guess is the USA?).

Are we really that imperial?

Anyway, I'm confused about this mix of metric and US measurements. I realize that car tires have both at the same time but for different things.

For example, the P250/50R18 designation is a mix of units for different measurements

  1. P = passenger
  2. 250 = millimeters of tread width
  3. 50 = percent width being the height in millimeters
  4. R = radial
  5. 18 = diameter in inches

So they mix letters, percents, millimeters, and inches but each one designates a different measurement.

Is it the same with the mix of units on the Schrader valve threads? The reason I ask is that there are only two measurements:

  1. Nominal diameter (thread root & thread crown)
  2. Threads per measurement unit

Given there are only really two measurements on a valve stem nut selection, I thought the two lines in the Wikipedia weren't a mix but just two ways of measuring the same thing?

Aren't these two different measurements measuring the same thing?

  1. Metric: 7.7 mm OD, 6.9 mm thread root, 0.794 mm pitch
  2. USA: 0.305 in OD, 0.271 in thread root, 32 TPI pitch

Right? That means it's *not* a mix. It's just like measuring a 5/32 and 4mm bolt, where both use the same wrech.

My question is: Isn't the tire valve NOT a mix of measurement standards?

Reply to
Leon Schneider

If you're going to be doing tens, hundreds, or thousands of wheels then get the best tool that you can afford. Usually that means the most expensive.

Reply to
Paul in Houston TX

Some alloy wheels and all large trucks use the nut type. They just unscrew, but they rarely need replacing unless obviously damaged.

Reply to
Paul in Houston TX

No, Imperial measures are not the same as US measures. An Imperial pint is

0.57 litres, while a US liquid pint is 0.47 litres.

US measures, Imperial measures, and English measures are all different.

That's how it goes. I've seen pressure gauges in pounds/cm2, even. We live in that kind of world.

It depends how the original document specifies it. But you could think about it either way if you were setting a lathe up.

I don't know, I haven't read the original specification document. It's likely written in terms of ordinary US standards, given when and where it came about.

It's not a standard SAE thread, but then there are an infinite number of possible threads and only a very few of them are standard SAE threads.

--scott

Reply to
Scott Dorsey

Right and Schrader (1890-ish) predates SAE anyway. Prior standards were UNC/UNF, before that NC/NF and before that Whitworth 55 degree threads in an era when many manufacturers of many things made up thread formats as they went along.

Reply to
AMuzi

I use "bolt in" stems on all of my vehicles now since I lost 4 stems in one trip on my PT Cruiser. That was Kitchener to PEI and back.

Reply to
clare

You got'er Cotter. Just tighten with a socket wrench.

Reply to
clare

Imperial is referring to the british system, which you yanks have hung onto with so much love since the revolution, and the britts have pretrty much replaced with Metric.

>
Reply to
clare

We did not hang onto it, we created totally new standards based only vaguely on the British standards. So a pint of beer here gives you substantially less beer than it does in London.

It's true that the US is the only country left in the world still using the British Thermal Unit.

--scott

Reply to
Scott Dorsey

snipped-for-privacy@snyder.on.ca wrote on Wed, 07 Dec 2016 14:56:28 -0500:

How do you *lose* stems?

I would think what gets most stems is curb damage, which is gonna happen no matter what type of stem (I'm guessing).

The second thing that I would guess gets most stems is ozone damage, which, again, is gonna happen to all rubber stems.

I guess they can use better rubber (something better than buna anyway), and I guess they can use more steel and/or brass (but then it's heavier).

So it seems to be a tradeoff.

Reply to
Leon Schneider

snipped-for-privacy@snyder.on.ca wrote on Wed, 07 Dec 2016 14:57:20 -0500:

Thanks.

I wonder which is better *quality*?

I suspect neither is better than the other.

I would "guess" (ASSume) that the one with nuts is *heavier* (which is a bad thing) and more expensive (another bad thing).

I doubt it seals any better on a steel wheel (guessing again though).

Does it seal better on an alloy wheel?

Reply to
Leon Schneider

Paul in Houston TX wrote on Wed, 07 Dec 2016 12:13:43 -0600:

Thanks for letting me know. I've never removed a tire valve before, so, this is a first (I'm repairing a tire that has a hole in the middle of the terad).

Reply to
Leon Schneider

Paul in Houston TX wrote on Wed, 07 Dec 2016 12:11:05 -0600:

I appreciate the insight but you hit a sore point with me so please don't take my diatribe below personally - but I've heard too many people say what you just said, which I think is the wrong approach entirely.

You don't approach a tool from a cost perspective; you approach a tool from the quality of results perspective.

I realize you said "usually", so, I agree that you're already on board, when I say that choosing tool-quality by cost is entirely the wrong logic, but the other half of what you said is the correct logic, which is to use the best tool if you need it.

Whether or not it is expensive is completly meaningless (most people simply

*assume* expensive stuff is better becuase it's a simple number and they can handle numbers but they can't handle myriad technical details when comparing two different tools).

For example, a 100K dollar alignment system may not be any more accurate than a $500 alignment system, but it does stuff that the shop needs, e.g., it allows dumber people to operate it and it allows hands-free measurements and it allows cars to be easily ramped on and off and it allows printing of the results, etc.

None of that has any bearing on the quality of the results and all of that raises the expense of the machine such that the local morons down the street think you have to buy an alignment tool for 100K dollars just to get a "good" alignment.

You can get a good alignment for probably 100 dollars in tools, and certainly for 500 dollars in tools; but it won't have all that time-saving stuff (where for a mechanic, time is money).

In contrast to your point, it may very well be that a $100 cellphone gets you as good an alignment as a $100K alignment tool.

The only thing that matters is the quality of the results. The cost of the tool isn't a factor in the quality of the results.

To the point, I'm not positive yet because I haven't done it, but I would bet that the quality of results from using a nail inside the tire valve when seating it is as good as the quality of results from using that $25 grooved swivel-head lever tool just as the quality of results when removing the valve with a utility knife is probably as good as the quality of results when using that fancy tool.

PS: I didn't aim this *at* you, but at the team becuase too many people use "cost" of things as a "quality" measurement - and it's never the case. People just use "cost" because they don't understand quality but they understand numbers such as numbers of dollars. But it's the wrong way of looking at tools (it's a factor though).

Reply to
Leon Schneider

and the inch, foot, mile, fehrenheit temperatures, lbs and ounces and tons (as compared to tonnes)and a whole lot of other measurements you did NOT change.. Your fluid measure was changed to short-change the brits.

Reply to
clare

I had 4 stems crack and loose air on the trip. They were all nice short stems less than a year old, installed with the new tires by the tire shop. It ends up they were crappy chinese crap stems, but 4 for 4 is BAD. I have alloy rims for summer and winter wheels on the truck - all with bolt-ins. I have bolt-ins on the summer alloys for the Tautus. I bought a set of used snows on alloys for the Taurus this fall. They stiull have the rubber cores, but I have a set of bolt-ins sitting in the wings - ready to go in.

Reply to
clare

The aluminum bolt ins are, if anything, only a few gramms heavier than the rubber ones. They do seal better on boyh steel and alloy because the rubber seal is compressed much more positively than the rubber stem, forming a VERY tight seal.They are a bit more expensive - I think I paid something like $1.50 each for the bolt-ins. Rubber ones are about $1.30 on e-bay and $2.00 at the tire shop - so it's pretty much a toss-up - and they last for years.

Curb damage is not an issue with either if you use short stems - and with expensive alloy rims I stay well away from curbs anyway.

Reply to
clare

Just make sure the repair is done properly. Anything bigger than a nail hole I consider to be NOT REPAIRABLE on today's radial tires. (and I spent many years in the auto repair and tire businesses)

Reply to
clare

I have long held to the position "never buy the cheapest or the most expensive, because you will be overpaying for either one"

Reply to
clare

Sorry - I just checked again, and you can buy the chinese rubber snap-ins for about $0.50 apiece on e-bay - if you don't care what quality the rubber is.

Reply to
clare

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