The simplest way to answer that is to point out that there are numerous good ones see the list at the end of this article for a few suggestions , so it's important that you know what a torque wrench does and what you need to know to find the best torque wrench for you. The difference between a basic wrench and a torque wrench is that the latter indicates—with either an electronic window, a clicking noise, a needle, or a gauge—exactly how much force is being applied to its handle.
It's important, but not well-known, that many fasteners require a very specific tightening specification. When it comes to certain nuts and bolts on cars, guessing it's "tight enough" is almost never right. Why is it important to know precisely how much force or torque is being applied? Too loose and the fastener might back off, causing an obvious issue. Too tight and the fastener or the fastened part might be damaged or distorted.
Overtightened lug nuts on a wheel, for example, can lead to brake-rotor warping, less effective stopping, premature brake wear, and the significant inconvenience of stuck lugs.
You could even cause a wheel stud the threaded part to snap off. Not tightening those lug nuts enough, on the other hand, could actually cause your lugs to loosen, fall off, and cause a wheel to fall off.
That's why most owner's manuals have a torque specification for lug nuts. If you plan to do any major work on your engine or on some major powertrain components, you absolutely need a torque wrench. Overtightening cylinder-head bolts, for instance, can easily cause expensive damage and catastrophic coolant loss.
Too-tight exhaust manifold bolts can cause the manifold to crack. Torque specs are so critical to proper car repair that most shop manuals provide them along with repair steps and then also include them in back-page tables with fastener location, designation, and individual specs. Torque force can be measured in units of meter-kilograms mkg , newton-meters Nm , and pound-feet lb-ft.
If you're buying a new wrench, make sure it's calibrated with the same units used in your repair procedures or have a conversion table handy. Most vehicles sold in the United States have torque specs expressed in lb-ft. The smaller ones are generally used for things like installing delicate temperature switches in fragile cast housings.
The larger ones are used to put big twist on crank-pulley or transmission-gear nuts. As one kilogram exerts a force of roughly 9. Or Allan McNish. This means that if you compare two engines with different torque outputs, the higher torque motor will always make more horsepower at any given engine speed.
However, many high torque engines are not built to rev that highly think of a punchy diesel , so ultimate power figures are often compromised. In contrast, a high-revving petrol sports car may be engineered to have a lower torque figure, but its extreme power delivery at high engine speeds allows it to go faster. Can you explain torque in 25 words or less? Have a go in the comments section below Skip to Content Skip to Footer. What is torque? Simply multiplying the two numbers gives us the required torque figure in Newton metres: 50 N x 0.
Which is better, torque or horsepower? Share this on Twitter Share this on Facebook Email. Most Popular. New electric car charger revealed alongside announcement that UK will ban the sale of all new non-zero-emission HGVs by However, for lug nuts, engine components, and other more serious important bolts you should always use the proper torque specifications directly from the Factory Service Manual for your car. Technicians are not looking at torque specs for every bolt on your car.
Even if they know it is in the Factory Service Manual, they are not always going to look and torque every bolt to spec. I always ask a tire shop before they start working, can you please torque the wheels with a Torque Wrench to insert the torque spec you want here. Do they look up your exact factory lug nut torque spec on your Mazda 3? Most smaller sized cars with a normal amount of lugs nuts are usually around ft-lbs.
I typically use 85 ft-lbs on all smaller sized cars and look up the values if it is at all a heavy duty truck or van.
Those torque values are usually around for lug nuts. They have a tendency to loosen up over time. Are there certain things that you should always be using a torque wrench for? For these items, is a high-quality torque wrench absolutely necessary?
Sure, you can. Should you? Probably not. Do they also need to be torqued to spec their timing belt cover bolts down to the inch-pound? Expert technicians, shade tree mechanics, and the grease monkey down the street all have developed over time a feeling for torque.
It is a feeling you just get used to with time, time spent wrenching on everything with different sized wrenches, ratchets, breaker bars, etc. You break bolts, you snap things, you curse and swear and learn. Just watch the first 30 seconds of this video by Eric The Car Guy.
He explains how breaking bolts is just part of the process. He was calling to ask me if there was a problem with the bolts, or was he tightening them too much? You do not need to jump on the wrench!!! Dude, just put them on pretty tight using the wrench and just using your body weight to push down. Drive it over here ASAP and we will fix the two studs. Only two broke through. Can I please bring it over so you can fix it? I hang up and go make sure my Milwaukee ft-lb impact gun has two full batteries.
Jeez, I hope this thing can take them off. Long story short. We got it fixed, and Andy learned about what 85 ft-lbs the torque spec for his lug nuts actually feels like. He had exclaimed after I gave him a lesson in torque. I have broken my fair share of nuts, lug nuts, and other fasteners. If you are a good technician that works often, you will break your fair share of bolts as well.
Might as well be as prepared as possible to avoid those situations. If they do happen, you need to be sure you have a game plan in place to remove the broken fastener. Best do it in a safe place no risk as much as possible to develop your feel. Find the closest Pick-N-Pull or other similar junkyards where you can walk around and pull your own parts.
In fact, I am sure I will get blowback. But there is a simple truth, the more you break bolts the more you develop a feeling of when a bolt is right about to break. The best place to find tons of cars that no one cares about and plenty of bolts to break is your nearest pick-n-pull. My only advice is to pick a car that is the least wanted car on the lot. Find the most mangled car. Usually like a Mercury Villager van in the far back will work great. Start breaking stuff. Try some small bolts first 10mm, 12mm, 14mm get a feel for when they feel tight then go past that.
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