ThreeH 2 Pack Momentsleutel RF Connector 5/16 ''Drive Size 1 Nm SMA Momentsleutel 8mm Opening Draagbare Sleutel

These are extremely well-made, high quality torque wrenches. They lack adjustment of any kind - they fit SMA connector nuts - size is not adjustable, torque limit is not adjustable. I find that a feature, to be honest - it means I won't be tempted to drag these out for another task, and not put them back where they belong - I just keep one with my SDRs, and one with my ham stuff, and they're always handy when needed. They do work great - I'm playing with RTL-SDRs, and so have a lot of SMA antennas, cables, etc., and they are fragile relative to their bigger N, SO-239, and even BNC cousins, these wrenches mean I can assemble quickly and solidly, without having to be too careful to not over-torque anything. Very handy.

When I tighten my SMA nuts by hand, they frequently come loose. This SMA torque wrench solves that problem, by putting the proper amount of torque on the connector. I must warn you, don't use with with a double female connector, or it may get stuck. I realized I made that mistake, almost the instant I did it, and it took me close to 10 minutes to figure out how to get that adapter off without damage. in the bottom of the handle, is a nut, which I'm sure is to adjust the tension of the wrench. Overall, this feels like a nicely made torque wrench, that works well, and saves me some headache. If you work with SMA, then I can strongly recommend you get a torque wrench, like this one.

At first glance, you might wonder why on earth you would need something pricey like this when a standard wrench will do the job. However, if you've done enough RF electronics, you also know that it's fairly easy to over- or under-tighten SMA connectors, which, in turn, can deteriorate the connection and make RF signal issues difficult to diagnose. Most of us "do it by feel." However, these wrenches are calibrated to a repeatable proper torque (ISO 6789 and ASME standards). Did I know what those standards were before? Absolutely not....I think I mentioned already...I did it by feel...At any rate, I make many connections to my Nano VNA and other test cables, and it's nice to have this around when I need it. You use it with a standard wrench to ensure the SMA connector is properly tightened...but not over-tightened. The wrench even comes with a certificate of calibration! Since it's sold as a precision piece of gear, it comes packaged like one. At first, I didn't understand why the packaging was overdone, but after reviewing everything more carefully, I understand better. NOTE: The English directions are actually pretty good.The bottom of the unit is threaded, but I have no idea why. Nothing is mentioned in the directions. It's some kind of feature that I'm unaware of (or it's unnecessary—I'm not sure which).I probably didn't need four of these, but since they recommend re-calibrating every 5000 uses, I'll just tuck two away for future use.I took off one star because they are still a tad 'pricey' - even though I like them. Also, it bothers me that I don't know what the tapped bottom is for, and it keeps me up at night. But now that I have given it four stars, I can sleep again.All that said - I'm glad I own them.

These wrenches are designed specifically to work with coax connectors but in the end, they are still wrenches and can be used anywhere you might need to use a wrench as long as the width fits your needs.They are very solid but also lightweight. They don't take up much space and the bright blue boxes that they come in make it very easy to find them in my toolbox.

What do you hate more than not being able to unscrew with your hand something that has been overtightened??? My cable guy used some crazy tool to overtighten all my cables that were connected to the jacks in my house. These wrenches are perfect for getting the job done!!!