Left Hand Threads on Lug Nuts

ndemge

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Jul 15, 2002
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Figured this was more of a technical topic, and a little bit of stupid human trick.<br /><br />Sunday morning I was going to pull the Left Axle/drum off my '84 F250 to do a break job, axle seal and brake cylinder.<br /><br />could NOT get the lug nuts off, fought them for an hour, finally gave up figuring I'd have to rent a 1" impact, as the 3/4" my brother had wasn't doing it. (Ingersall Rand)<br /><br />....Then talking to my brother that night, he mentioned, ya know, they used left hand threads for a few years there.......<br /><br />SUNABICH.... took out a flashlight and looked at it a bit closer, and sure enough. Grabbed the 4-way out of the bed and was able to break one loose. Now just gotta wait for another day with time to do it.
 

ZmOz

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Re: Left Hand Threads on Lug Nuts

Shoulda bought a Chevy. :p
 

Scaaty

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Re: Left Hand Threads on Lug Nuts

Amazing....stupid idea, but still amazing. ZERO reason for LH threads
 

Dunaruna

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Re: Left Hand Threads on Lug Nuts

Depends on the cut of the thread. Many car makers used LH threads way back when. Chrysler comes to mind.<br /><br />Some european cars still have them.
 

noelm

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Re: Left Hand Threads on Lug Nuts

Hey Dunaruna those Chryslers were of couse called Valiants out here, and I once got a flat tyre in Lithgow about 3am, now lithgow in July at 3am is kind like being at the south pole, now not being my car, I did not know about left hand wheel nuts, and tried for half an hour in the freezing dark with bad tools to try to get that wheel off, ended up sleeping in the car till daylight, and then found out about the threads, got wheel off and spare was flat as well, looonngg walk into town for repairs that day.
 

Dunaruna

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Re: Left Hand Threads on Lug Nuts

noelm, I think that caught a lot of people off guard initially, many a wheel stud was snapped off!<br /><br />If my memory serves, the L/H nuts had a small groove cut into the edges of the flats (the bit that the socket grabs) to define it as a L/H thread.
 

BoatBuoy

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May 29, 2004
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Re: Left Hand Threads on Lug Nuts

Originally posted by Dunaruna:<br /> If my memory serves, the L/H nuts had a small groove cut into the edges of the flats (the bit that the socket grabs) to define it as a L/H thread.
Not only that, the end of the stud had an "L" stamped in it.
 

JB

Honorary Moderator Emeritus
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Mar 25, 2001
Messages
45,907
Re: Left Hand Threads on Lug Nuts

Many large mowers use LH threaded bolts to hold the blades on. Had a similar experience to yours, Noel, with a finish mower. :mad:
 

Chief101

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Sep 29, 2005
Messages
591
Re: Left Hand Threads on Lug Nuts

Same with alot of table saws, radial arm saws. and chop saws. A safety feature. ;)
 

Haut Medoc

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10,645
Re: Left Hand Threads on Lug Nuts

Floor sanders,too....It's a rotation thing...JK
 

SS MAYFLOAT

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May 17, 2001
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Re: Left Hand Threads on Lug Nuts

They use left handed threads so that when starting such as a saw, the torque actually tries to tighten the bolt/nut. Of course it depends on the rotation of the item.
 

snapperbait

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Aug 20, 2002
Messages
5,754
Re: Left Hand Threads on Lug Nuts

GM... serpentine belt tentioner pully bolt = lefty thread.... :mad: <br /><br />Then there's them metric bolts & nuts... :mad:
 

dolluper

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Jul 19, 2004
Messages
3,904
Re: Left Hand Threads on Lug Nuts

Old intrenationals played that trick to,but they put the L on the end of the stud like plymouth,dodge,and chrysler did,don't forget about your toilet fush handle left hand thread too
 

Dunaruna

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Re: Left Hand Threads on Lug Nuts

Originally posted by snapperbait:<br /> GM... serpentine belt tentioner pully bolt = lefty thread.... :mad: <br /><br />
Because to release the tension on the belt, you need to overcome the spring by turning the bolt anticlockwise, if it was a R/H thread it would loosen.<br /><br />i don't get why the U.S. is still hung up on imperial. A lot of your TV shows use metric. CSI are always quoting cm & kilograms etc - what's all that about?<br /><br />Do you use both?
 

T S N

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Sep 4, 2003
Messages
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Re: Left Hand Threads on Lug Nuts

Then we have to buy more wrenches.
 

KRS

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May 15, 2004
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Re: Left Hand Threads on Lug Nuts

left hand nut is a little different than the right hand one, but the doc said not to worry...
 

KRS

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Re: Left Hand Threads on Lug Nuts

CSI is a crock of poop Dunaruna, I watch it and laugh. My dad is in forensics for a very large metropolitan police department, and they are pretty off-base sometimes.<br /><br />As far as usage... when discussing something scientific, I notice we use metric; however when discussing casual distances and speed, such as for driving or land size, imperical (or standard as we call it) is more common. I don't know why everyone else does it wrong :)
 

KRS

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Re: Left Hand Threads on Lug Nuts

Propane bottle regulator, lefty-tighty too
 

AMD Rules

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Sep 23, 2004
Messages
1,707
Re: Left Hand Threads on Lug Nuts

Having a left hand thread on the end of a rotating shaft can be a safety features, as mentioned. They should be designed to tighten in the direction opposite to normal shaft rotation.<br /><br />On the other hand, unless you are driving a formula one car you won't find lug nuts on a passenger vehicle to be on the axis of rotation. A left hand lug thread serves no purpose other then to confuse the unlucky motorist.
 

KIGuy52

Petty Officer 1st Class
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Jul 22, 2005
Messages
210
Re: Left Hand Threads on Lug Nuts

The plastic cap that holds the blade on my small office fan has left-hand threads too. I discovered that when I installed a new high performance blade to increase airflow. Unfortunately, now the fan won't reach max rpm on the "high" setting. What blade pitch would you guys recommend for a 2-speed 8" Wal-Mart portable fan? Should I maybe go to a 4-blader? I like this fan because it has a round base plus an optional clamp attachment so I can mount it to my shelf, and the "Roll Back" price was only $6.94. I guess I should post this in the "prop questions" forum. Sorry.
 
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