FTM 124: Torque Wrenching, Part 2

fastener Training Minute 124: Torque Wrenching Part 2

This edition of the Fastener Training Minute with Carmen Vertullo was originally published January 16, 2018 as “different types of  torque wrenches” during episode 124 of Fully Threaded Radio.

Well hi everybody, welcome to the Fastener Training Minute. This is Carmen Vertullo coming to you from the Fastener Training Institute and the Carver FAÇT Center where we do fastening applications, consulting and training here in San Diego.

Today is the second part in what we loosely call a series, and the topic of our series is torque wrenches. Last time we talked about using extensions with torque wrenches. This time, we’re going to broaden it up a little bit and we’re going to discuss the two categories of torque wrenches. Now, I think there are two broad categories. There probably are somewhere between 6 and 20 different types of torque wrenches depending on how you count them. But you need to know about the two broad categories of torque wrenches, especially if you’re a supplier or involved with any kind of quality assurance when it comes to Fasteners. When we return I’ll tell you what those two broad categories are and why it’s important that you know the difference.

Welcome back to the Fastener Training Minute, this is Carmen Vertullo. Today we are talking about torque wrenches and specifically two broad categories of torque wrenches. Those two categories are known as indicating torque wrenches and control torque wrenches. The one you’re probably most familiar with if you are in your garage playing with your car, is the control torque wrench, commonly known as a clicker. This tool is designed to allow you to put a particular setting into the torque wrench and control the torque that you apply. It doesn’t actually measure anything. There’s no indicator on it. Other than that little micrometer on the handle that tells you what the perceived or expected torque should be that you apply. Now there are other types of control torque wrenches where they have a single setting, or a more or less permanent setting that are used in manufacturing and production automotive assembly operations all the time.

The other broad category, my favorite, is called the indicating torque wrench. Now the purpose of an indicating torque wrench is to tell you how much torque you applied. In other words, you’re going to take this torque wrench, you’re going to put it on a bolt, you have no control over it. You simply pull the handle and you look at the dial. There’s a dial there. It’s got a needle on it, and that needle is going to move and it’s going to sweep another needle along with it. That other needle called the memory needle the memory needle stays put and it tells you how much torque you actually applied. These types of torque wrenches are very important for quality assurance, or doing a process called a torque audit which we will discuss then another episode. Indicating torque wrenches are also used for things like testing lock nuts and the installation effectiveness of nylon patch or pellet type locking elements.

Now there’s also a hybrid that comes between these two, where we have a torque wrench that can actually indicate and control. These are very popular in large sizes in the structural bolting business, and they really don’t control that well because you just kind of crank on them and when you hear a beep or see a light go off you let go. The human being has a lot to do with that control part of it and nowadays we have electronic torque wrenches that do both jobs fairly well. But just be aware that when we’re talking about torque wrenches you need to know what the application is. Are you trying to control the torque that you’re applying or you trying to measure the torque that you’re applying. To measure the torque we use an indicating torque wrench and to control the torque that we’re applying we use a control torque wrench such as a clicker.

Well, those are the two broad categories of torque wrenches. Later on we’ll talk about some of the subcategories and I hope you’ll join us then. This has been Carmen Vertullo with your Fastener Training Minute.

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