Can you teach me more about lug bolts & related tire tools?

The impact socket is superior for that application - whether using an impact driver or not. A 12 point socket is better in situations where fine motion is required.

Yes, they are there from the factory.

To make it fit in the jack bag

The Micrometer adjusting "click" is easier to use.

A "speed handle" is very handy for spinning nuts on and off after breaking them loose and before torquing. I still use mine a lot. - not just for wheel nuts,

No.

Looks like a small staple.

You are best to rotate only front to back on MOST vehicles -and MUST do so with "directional" tires.

In over 40 years Ihave NEVER done side to side rotations. (and I'm a mechanic)

Four thousand miles? Why so often? Is that what the owner's manual recommends?

I knowof people that have done side to side on car with different size front and back, but it seems about useless.

I also rotate with oil changes at 7500. IMO, 4000 is a bit too soon but if you have the time and engergy . . .

There is no doubt that 4K miles is the correct number because the alignment is correct and the front tires get a palpable feathering on the outside edges after about 4K miles.

It's been reliable, as this is the fourth rotation of these tires, and the same thing happens every single time, where I've actually been doing it not by mileage but by the feeling of the tires - but when I write down the miles, it's just about every 4K miles.

The roads are very windy for miles at below 20 mph and very steep.

The impact socket has a radius at the points to remove the stress concentration that would split the socket when used with impact tools. It also contacts the nut on the strong flank and not the weak point.

A full hex is better than a 12 point for nearly all uses. You can always rotate the socket 1/4 turn on the 1/2" drive to get 12th of a turn when space to swing the bar is tight.

Why? Not all nuts have this mark, and in the UK nuts with this mark are generally used for hoses that contain inflammable gases.

The only way I know to "test" (but not "calibrate") a torque wrench is to have a double-headed bolt contraption that is long enough for two sockets to fit face to face.

Then I would put a torque wrench on each end, and lock one in a vise and twist the other where they should both show the same torque.

That only "tests" them. I don't know how to calibrate them because both could be wrong. And you have to "adjust" them if they are.

Does anyone know how to calibrate a torque wrench at home?

That makes sense! So the rounded corners take the 'stress' off the nut and the rounded corner also takes the stress off from the potential for a hairline crack of the socket wall?

I was wondering if a 12-point is "weaker" than a 6 point? Is at 6 point stronger, weaker, or the same stress on a nut/socket as a 12 point?

I never thought of that! The math confused me so may I reiterate what I "think" you just said?

Am I correct in assuming you're saying that you can rotate a 12-point socket by 1/12th, while you can only rotate a 6-point socket by 1/6th --- but ... if you cleverly rotate /both/ the 6-point socket by 1/6th and the half-inch socket wrench end of the socket by 1/4, you get the same effect?

Clamp head with handle horizontal; hang bucket of water measured distance from head; add water until clicks; weight bucket; do sum.

This is good to know that the impact socket is superior, probably for two reasons, right?

1. It has those radius corners (someone said it reduces stress on both the nuts and the socket itself).
2. It is stronger overall (presumably)

Since there is always a drawback, I think the drawback might be:

1. They're "fatter" it seems, than my normal sockets
2. They don't seem to come in 12-point sizes (at least mine aren't)

On a diagram, I see how hanging a known weight a known distance from the head will test the torque to see if it's correct ... but ...

And I can visualize how to mechanically clamp a bolt in a vise to hang the torque wrench on - but then - how do you calibrate the two types?

That's what I was wondering but I didn't know why.

Does a 12-point tend to round nuts more than a 6 point?

Why?

Is it because there's more force against the nut's point?

I just mean the right-angle simple bar extension that you have to have in order to keep the torque wrench away from the sidewall of the tire.

You have to have an extension no matter what, because the torque wrench hits the tire sidewall because the lug nuts are on the hub but the tire sidewall sticks out a few inches.

Even a deep socket isn't long enough, so the least I can add by way of extension is a deep socket plus a 2 or 3 inch extension bar (whatever I have that is shortest).

I was asking if I used a 3 inch extension bar off the deep socket, or, if I used a 6 inch extension bar, would it matter for the torque?

I think not - but I've heard people say use the shortest extension bar you can get your hands on. I don't understand why. It should be the same torque if I used a 16-inch extension bar, right?

I also wonder why the cuts are there, all at the same depth on the nut.

A friend I just spoke to says his car has them too, so, they're pretty common.

If they're made at the factory, why?

I can't disagree that the shape and length of a purposeful "lug wrench" is designed just for removing lug nuts, so certainly that's why it's curved the way it is (to fit around the tire sidewall).

Certainly smaller is easier to fit in a car.

Since you can't use a torque wrench and a lug wrench at the same time, I was wondering if they made it just short enough so that a normal person could not apply "too much" torque to the lug bolts?

Basically, I was asking if it's short because that way, a normal human can only apply about 85 foot pounds which is all they can do with that short bar and their hands?

Is that just an urban myth?

for gods sake get a life.

There are loads of videos on YouTube which may help - eg

- to a first approximation - acts through a point halfway along its length :)

If it's a wrench where you read the torque then you can just take a reading with a bucket of water and compare it to the results of you sum

- and repeat for heavier/lighter buckets.

If you've a hydraulic wrench then I pass.

I use single hex impact sockets for 99.9 percent of jobs, there are practically speaking no occasions when they are too fat to get somewhere. (better makes are thinner sided than cheap ones)

Unless you have 12 sided nuts/bolts, then you do not need 12 sided sockets (there are some odd cars/equipment which use 12 sided hardware)

yes, but it is so rarely needed it is not worth worrying about