Proper way to re-torque a bolt.

[KEITH KRAUSE]

Just a quick tip, mostly for the "newbies".
When you check the torque on your bolts, ALWAYS loosen them just a little bit first, then torque them down. After some time, bolts can become "stuck" and if you just torque them the way they are you will get a false high setting.
Also, if there is corrosion or rust, you need to clean them up to get an accurate setting. Badly corroded or rusted bolts/hardware may need replacing to avoid breaking under torque. And buy a quality torque wrench. The cheap "pointer" kinds are a waste of money. Buy one that "clicks", the twist and lock kind.
A WORD OF CAUTION: when checking the torque on HEAD bolts/nuts, loosen them just a bit, "cracking" them loose. You don't want to cause leaks by loosening them too much. Then re-torque.

[92G]

Thanks for the advice.

I wouldn't have thought of that, but it makes sense.

Epecially when you consider that static and dynamic torque are 2 different things becuase of the differences between static and dynamic friction. If you loosen them 1st, then you are measuring the dynamic torque which would seem to be what we're interested in. If you start with them tight, your are measuring the static torque, until they move.

Ok, I'm a geek.... :roll: .

Thanks again,

Terry

[Anonymous]

Geeks rule the world, Terry. Never apologize for that, but be proud.

Former math teacher and maker of geeks,

Nick

[argonsagas]

Geeks rule the world, Terry. Never apologize for that, but be proud.

Former math teacher and maker of geeks,

Nick

Fortunately, Nick's students never became endeered :roll: to him

[Anonymous]

Former math teacher and maker of geeks,

You might want to change the 'maker' to 'schooler' or similar.

[Anonymous]

The cheap "pointer" kinds are a waste of money.

Saying that beam type torque wrenches are a waste of money is a bit harsh and not accurate. Mechanics 'got away' with using them for decades before the new models arrived. The new ones are in most cases more accurate and easier to use, but that doesn't take away from their utility and value.

What we really want to measure when we assemble a motor is the 'stretch' of the bolt. Torque an indicator of that and is an approximation as such. What you are then doing is getting as accurate a measurement of an approximation as you can. Boggles the mind.

[moto_dan]

A little more info on Torque wrenches

http://www.metrologyconcepts.com/tips.html

[92G]

Geeks rule the world, Terry. Never apologize for that, but be proud. Former math teacher and maker of geeks

Cool, I have a Master's in Mathematics. . I'd be happy if I was king of my house, forget the world...

Terry

[KEITH KRAUSE]

The cheap "pointer" kinds are a waste of money.

Saying that beam type torque wrenches are a waste of money is a bit harsh and not accurate. Mechanics 'got away' with using them for decades before the new models arrived. The new ones are in most cases more accurate and easier to use, but that doesn't take away from their utility and value.

I only give advice that I would follow. I would not trust or use a 'pointer' torque wrench on anything. We have 'got away' with using a lot of things in the past, but when something becomes obsolete and you KNOW there's an improved version that will work better for you, then you should use it.
You said it yourself, the newer 'click' type torque wrenches are more accurate and easier to use. Why would you use something else?
The only time I use my 30 year old pointer wrench anymore is for a breaker bar.

[moto_dan]

Click type or beam type...it doesn't matter if they are calibrated and used correctly. I ran across message on calibrating your TW of choice and thought it interesting.
http://www.dieseldoctor.com/messageboard/data/229.html

[Anonymous]

Why would you use something else?

You would use the beam type if money is an issue. As I said before, there is nothing wrong with the old beam type wrenchs. Many vehicles have been built with them - many, many, many hp type and racers.

The first thing you need to understand is that what we are trying to do is measure the stretch of the bolt. Torque is just used as a cross reference to that since stretch is a hard measurement to get at. Stretch is affected by many things and is not a constant for bolts - even the same type and grade. So - torque is not an absolute measurement of 'stretch' - just an approximation. Remember, stretch is what we are after.

Longevity of an engine has infinitely more to do with the skills of the builder than the type of torque wrench.

The only time I use my 30 year old pointer wrench anymore is for a breaker bar.

Why would you do that - it isn't long enough for a breaker bar and it has flex. A very poor breaker bar IMHO. Do you use screw drivers as pry bars and chisels too? Either you are trying to make a point - or you are not as bright as I thought.

[KEITH KRAUSE]

The only time I use my 30 year old pointer wrench anymore is for a breaker bar.

Why would you do that - it isn't long enough for a breaker bar and it has flex. A very poor breaker bar IMHO. Do you use screw drivers as pry bars and chisels too? Either you are trying to make a point - or you are not as bright as I thought.[/quote]

Swanny, if it makes you feel better, use any wrench you like. In our previous replies we both agreed the click type are more accurate. That's what I'll use.
As for my old pointer wrench being a poor breaking bar, it works pretty good on lug nuts and other 100 ft/lb stuff.
NO, I don't use screwdrivers as pry bars and chisels. I did when I was 15, broke off a few tips too.
NO, I'm not trying to make a point, but it appears you are.
I made a topic to try to help someone, not to argue about torque wrenches.
And as for you taking this to another level and questioning how bright I am, I'd say I'm average, no more, no less.
It's easy to insult me when you're 1,000 miles away.

[Anonymous]

Keith, I agree you were trying to help someone with retorquing, but you also added the comments about beam type bars being worthless. That in turn opened the discussion up on this track.

I pointed out several times that when tightening bolts it is stretch you are after, not torque. The relationship is not exact. You ignored this point. The last comment was probably not necessary.

You are fixated strictly on accuracy, when the torque wrench does not build the motor. I'll take an expert mechanic with a set of open end wrenches over a novice with a torque wrench any day.

If money is an issue, there is nothing wrong with a beam type torue wrench. As a matter of fact, you would be far better off spending the money you saved on the 'clicker' and buying a set of tap and dies. You can't get an accurate torque reading without first cleaning the mating surfaces.

I agree, the insult at the end was easy at 1000 miles. It would be easy in the same room also. I don't say anything in these forums I would not say face-to-face.

[KEITH KRAUSE]

I don't think I'm fixated on accuracy, I just prefer to use the most accurate tool.
It's too bad you have to take a simple topic and make it a personal thing.
It's also too bad you feel the need to throw this tough guy stuff at me.
You don't know me and I don't know you. You don't have any way of knowing what you would say if we were in the same room.
All this, because of a torque wrench comment. Do other peoples opinions get you so worked up?

[Anonymous]

I talked to some expert mechanics around here for cars, diesels, and motorcycles, and they all agree that they would much rather have a clicker type. The general consensus was that the beam type are OK for wide torque tolerance ranges in the upper end, i.e. 75 or more pounds. I'm not trying to refute or support anyone, but if the question is whether or not the clicker type is significantly better, the answer seems to be that it is.

Harrison