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diameter and pitch air tire valves

diameter and pitch air tire valves

diameter and pitch air tire valves

Hi all , does any know what are the nominal dioamter and pitch in TPI of the air valves at the auto and bicyles tires or tube.
I meassure about .300 Inch outside dia, and  32 TPI(thread per inch), but it does not mach with any known tap or die.

feel free to ask at



Gabriel Calos De Vit

RE: diameter and pitch air tire valves

You were very close. Standard automotive (car) Schrader valve dimension is

7.7 mm OD

32 tpi, or 0.794 mm pitch

Minor diameter is 6.9

Thread designation is .305-32 or 7.7-32

Nice mix of inches and millimetres!


Greg Locock

RE: diameter and pitch air tire valves

Hi Greg, thanks for it .

Which standar cover this thread?

RE: diameter and pitch air tire valves

Here I'm again:

see what I find looking for it.

by John L. Campbell

What part on your automobile hasn’t changed its design in over 100 years? Sounds like a good trivia question, doesn’t it? The answer: it’s the tire valve. Whether your tires are tubeless or have a tube, there’s a tire valve on every wheel, a design patented in 1898.

The Duryea brothers were the first car manufacturers in America to put pneumatic tires on their horse-less carriage; and if it hadn’t been for the invention of the tire valve by August Schrader and his son, George, there wouldn’t have been an air-tight seal to keep the tires from going flat over time. The Schrader-valve has been an American standard for 102 consecutive years and a world standard for more than 76 years. George Schrader is credited with the pioneering effort and experimental work that resulted in patents issued for the current housing design with its removable and interchangeable core and cap.

The late David Beecroft, former president of the Society of Automotive Engineers, said, "Tire valve development is deservedly the ace of automotive standardization. The valve interior or core of today fits the valve housing of l898 with equal facility and the removable valve core and the cap with the tire valve housing comprise the only standard in world-wide use in the automotive industry."

If August Schrader hadn’t setup his machine shop in Manhattan within a few blocks of Charles Goodyear’s rubber vulcanizing plant, the two geniuses might never have met.

Goodyear patented rubber vulcanizing in l839 and August Schrader arrived in New York from Hanover, Germany, a year later. Four years after Schrader’s arrival in America, the industrious German started his own company. With over thirty rubber depots and warehouses in Manhattan Schrader found himself immersed in the new growth industry. To accommodate the needs of these rubber manufacturers Schrader machined molds and brass fittings for companies like Goodyear and Union India Rubber Company.

In l890, after some English cyclists outclassed all competition with their cushioned pneumatic tires at a race in Niagara Falls, one of the early tire manufacturers asked Schrader to develop an air-tight seal for pneumatic tires. Two years later Schrader and his son, George, applied for their first patent on the Schrader tire valve, improvements of which became the standard for the world and the nucleus for their company’s success.

The tiny valve cores are machined from brass rod and chrome plated. According to Mike Doster, a design engineer, seven different sizes of valve inserts for today’s tubeless tires and a couple dozen different lengths are made. "But, they’re all basically the same design, which hasn’t changed in over 100 years."

RE: diameter and pitch air tire valves

Tire and Rim Association, Copley, Ohio


Greg Locock

RE: diameter and pitch air tire valves

I found all this data about Tire and Rim.

The Tire and Rim Association, Inc.
175 Montrose West Avenue
Suite 150
Copley, OH 44321

Phone: 330/666-8121
Fax: 330/666-8340

Email: TireandRim@aol.com

RE: diameter and pitch air tire valves

outside diameter of a standard tire valve thread is .302 and has 32 tpi. .302-32

RE: diameter and pitch air tire valves

Wow, I was doing a search on schrader valves and found this site.

Since you guys know so much about it, any idea where I can purchase a screw or bolt that will thread in to the stem, in place of the valve.

Thanks for any help!!!!


RE: diameter and pitch air tire valves

Hi :
Try at tire and rim association


You can reach me at k281969@hotmail.com
but keep your post here for mutual benefits.

RE: diameter and pitch air tire valves

Thanks Pardal;

Yesterday I called a local nut/bolt supplier to see if they can get a 5/16-32 UNEF screw.  That might be close enough to fit.  They should be calling me back today.

RE: diameter and pitch air tire valves


tell me if it works.


You can reach me at k281969@hotmail.com
but keep your post here for mutual benefits.

RE: diameter and pitch air tire valves

The bolt supplier came back with a rediculous quote (something like $10/ea).  Think I'll just purchase the $2 tire valve tool from my local auto parts supplier and punch out the threaded section that I need.


RE: diameter and pitch air tire valves

The internal thread is 0.209 inches (5.3mm) by 36 threads per inch (0.706mm pitch),

the external thread is 0.302 inches (7.7mm) by 32 threads per inch (0.794mm pitch).

Both are UNS thread form (60°???)

I have not yet found the tapping sizes for these, but I will keep you posted.

RE: diameter and pitch air tire valves

Followin the  info submited by TIRE AND RIM

The thread for the valve core for valves used in passanger cars is .206-36
which is a special valve thread.

You can reach me at k281969@hotmail.com
but keep your post here for mutual benefits.

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