Wrong section
It was in the classifieds section originally. Looks like a mod moved it.Why is a thread about torque wrenches in the General Tool Discussion forum the wrong section?
I sell them quite often. I tell the guys to leave the batteries out of them if they are not using them. Prevents the cheap little batteries from leaking as well...
I have 3 CDI computorq3 wrenches (1/4, 3/8 amd 1/2) and use them often. Mine takes the A123 size batteries (they share that size with my surefire lights) but the auto shutoff feature keeps them from running down the battery. They have the yellow (getting close), green (on torque) and red (you screwed the pooch) lights that make them easy to use when you are not in a good position to see the display.
They also have the different "beeps" that will let you know the same three stages if you are pulling out of sight. You can also look at the display and get a returned value on the last bolt torqued. I don't use the 1/2 very often (prefer my SO clicker for those) but when running down head bolts, that is the one I usually grab.
Overall, they are nice but I wish that I had bought the tech angle style instead of the regular one for those times when I need to deal with a "torque to yield" fastener. Easy to get around with a dial but still, wish I had gone with them instead.
I hate anything with batteries. They always go dead at inopportune times....
Teken,
The torque to yield specs will give a value to torque the bolt down plus an additional amount to turn the fastener (given in degrees). This forces the bolt to stretch and put as much load on the connected parts as possible. The tricky part is to let the bolt elongate (stretch) but not past the point of yielding (bolt failure..).
Done right, the bolt will stretch but when the load is taken away, it will return to its normal length. This is what typically happens with "torque plus angle" bolts. For "torque to yield" bolts, the angle is increased (increasing the torque applied on the bolt) just to the point that the bolt will be permanently longer once the load is removed. It will not fail at that point but will produce the maximum clamping force on the connected parts.
If you go much past this point however, the bolt will start necking down and fail prematurely with disastrous results in your engine or other machinery.

That is fantastic insight and clarification. As always I thank you and the others for sharing their knowledge with me . . .![]()
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Teken,
One other thing to remember, if you run across these bolts on a car, make sure you replace them when putting it back together. You don't want to ruin a nice engine over the cost of a few bolts.
Teken,
The torque to yield specs will give a value to torque the bolt down plus an additional amount to turn the fastener (given in degrees). This forces the bolt to stretch and put as much load on the connected parts as possible. The tricky part is to let the bolt elongate (stretch) but not past the point of yielding (bolt failure..).
Done right, the bolt will stretch but when the load is taken away, it will return to its normal length. This is what typically happens with "torque plus angle" bolts. For "torque to yield" bolts, the angle is increased (increasing the torque applied on the bolt) just to the point that the bolt will be permanently longer once the load is removed. It will not fail at that point but will produce the maximum clamping force on the connected parts.
If you go much past this point however, the bolt will start necking down and fail prematurely with disastrous results in your engine or other machinery.
A couple of quick comments that might help in your decision making process... (Admittedly, I currently only own a SO 1/4" drive click type--I'm a tech. student still)
It's a fact that an electronic torque wrenches will cover a larger range of torques than a click type. This might mean that a tech could own fewer torque wrenches.
It's also my understanding that the electronic torque wrenches hold their calibration for a longer period of time. Since their operation is based upon a strain gauge, they do not suffer from metal fatigue like a click type (The click types have a large metal spring which, like any spring will fatigue, effecting calibration). This may, or may not, be an issue for you, depending on where you work. In some facets of aviation, for instance, ALL torque tools have to be sent out periodically for calibration. In this case it wouldn't matter which one you had. Also, an added bonus is that you don't have to zero-out the electronic type before storage as it is recommended you do with click type. I always forget to do this.

I've got a Snap on tech angle i think it's a fantastic piece of kit, it great when doing head work when needing to change from torque to angles. I've had mine nearly a year and haven't needed to change the batteries yet but i always take a battery out of it when it's not in use. I know the Tech angle is expensive but it's worth it.
I have about ten, but still bought two Tech Angles (3/8-1/2).
love 'em...
I don't know about other engines but, Mercedes has published specs for all their stretch bolts. If they are within spec there is no issue re-using them. Rod bolts and head bolts are commonly reused and run hundreds of thousands of miles.
Steve
Very interesting. I didn't know any of this. Which engines, or other applications, now require this?
I did know that in some applications that the fastener is intentionally stretched, thus the prohibition against re-use, but had never come across torque plus angle, let alone torque to yield. How about some pics?
Very interesting. I didn't know any of this. Which engines, or other applications, now require this?
I did know that in some applications that the fastener is intentionally stretched, thus the prohibition against re-use, but had never come across torque plus angle, let alone torque to yield. How about some pics?
I think a $10 harbor freight torque wrench does the same thing imo. My friend has an electronic torque wrench. It's neat but i don't think it's worth it unless your a "pro"
Very interesting. I didn't know any of this. Which engines, or other applications, now require this?
I did know that in some applications that the fastener is intentionally stretched, thus the prohibition against re-use, but had never come across torque plus angle, let alone torque to yield. How about some pics?
it is actually much easier to over torque with an electronic wrench and an inexperienced operator. all torque wrenchs must be turned slowly and smoothly. with a traditional click type the torque actually peaks at the click, dips down to a lower torque and then finally over torques if you keep pressure on the wrench. torque curve of a traditional click wrench http://www.mountztorque.com/learning-center/guide/selecting-proper-torque-wrenchi use a snap on tech wrench....i brought mine because i 'm told it is more precise than a standard click type, apparently....when a standard torque wrench reaches the correct torque setting it then clicks creating a breif moment of extra leverage...with a electronic/digital there isnt any of that clicking....and over torqing ...just a beep and a buzzz.....but i found i did have to take the batteries out after use or else they would go flat after being left in me box for a bit.......
Very interesting. I didn't know any of this. Which engines, or other applications, now require this?
I did know that in some applications that the fastener is intentionally stretched, thus the prohibition against re-use, but had never come across torque plus angle, let alone torque to yield. How about some pics?
Just about everything uses torque-to-yield bolts on it now. AFAIK, about all Ford head bolts are like this. They cannot be reused - an as noted, bolts are cheap. Why chance the work on used bolts. Unless you switch everything to ARP.

it is actually much easier to over torque with an electronic wrench and an inexperienced operator. all torque wrenchs must be turned slowly and smoothly. with a traditional click type the torque actually peaks at the click, dips down to a lower torque and then finally over torques if you keep pressure on the wrench.