ACDelco 3/8” & 1/2" Heavy Duty Digital Torque Adapters with Buzzer and LED Flash Notification – ISO 6789 Standards with Certificate of Calibration (1/2” (14.8 to 147.6 ft-lbs.))

It's been some time since i used this but all the features work as explained. The only problem is that setting the tool to alarm you when you reach the desired torque is just a bit convoluted. Don't get me wrong, it works perfectly but you must follow directions that are in the manual. If you don't, you're going to know something is amiss before you strip a bolt. There was something about setting the torque that wasn't as straightforward as it seems it should be. If you only use the tool all the time, no problem, you'll have the process down pat. If you use the tool only ocassionally, just make sure you keep that manual stored with the tool and follow the manual each time you use the tool. As for accuracy??? All I can say is I trust this tool much more for ehigh torque value than I trust my old, inexpensive torque wrenches that I have used and become familiar with over 15 years. I tested the tool against my torque wrenches for lower values and they were pretty close. I used this tool on a strongarm bar instead of using a torque wrench. Torque until the alarm goes off. Works great. If I need one of these that is calibrated for higher values, I will buy the same brand.

This review is written from Lagos, Nigeria for the ARM602-4 with 1/2" drive. I ordered this product when it was time to replace the cracked cylinder head gasket on my '09 Toyota Corolla with the 2ZR-FE engine. The product arrived in excellent condition and included the two batteries needed to operate it. The seller had earlier sent me instructions by e-mail on how to use it. It also includes an owner's manual with clear instructions. My impressions: it is easy to use. It is easy to learn how to use. It doesn't take you more than a few minutes to begin implementing what's written in the owner's manual (You, of course, do read manuals). Once you install the batteries you are ready to pop your square drive in and torque all sorts of things. There is a digital readout that's clear and easy to read in daylight; there is no backlight for dark places. The buzz that informs you about your target torque is loud and clear for probably most situations you'll find yourself. When you approach 90% of your set torque setting the beep begins and remains until you reach your preset torque in which case the urgent beep becomes a long buzz. You'll want to play with this tool when you first use it to get a feel for how far above torque you get it. There's a 'Peak' mode as well as 'Trace' mode - Peak mode saves a reading of the highest torque you've applied; I liked clearing this each time to see a new peak reading at the next attempt. With a few attempts I learnt how to slow down rotation to bring me as close to matching preset torque as possible, give or take. The Trace mode allows you see the torque reading in real time if that's what you want. You'll have to adjust the device to account for rotation so you can still see the screen while turning a bolt. Now, here is the catch: from my photo you can gauge the size of this tool - it will be impossible to use it in a few (or many situations) depending on the space in your engine. It was easy to employ for cylinder head bolts, camshaft bearing cap bolts, my right-hand engine mounts, intake manifold and then some bolts on the timing chain cover. The problem is that it was too large to allow me torque some bolts on the timing cover, exhaust manifold and alternator. I used it on most but the aforementioned few I had to torque by "feel". Also, this tool is calibrated for 20N.m - 200N.m (14.8 - 147.5 lb-ft). I found that all those 10mm bolts that required much smaller torques I just tightened by feel - the device won't register a readout until you reach 20 N.m, even when in trace mode. Another reviewer suggested to use this as a calibration tool for your other torque wrench instead and save yourself any headache. I do agree that another torque wrench may be needed to complement this. Over all, I am satisfied. This was all I used for the head gasket job for my car and I am pleased.

This is a good product. It is very easy to use compared to the Chineese designed variants on Amazon. Those are near impossible to quickly set. This one is pure simplicity with no memory functions, because you just don't need it its so quick to adjust. Comes with a certification and useful instruction manual. I just returned a half price competitor - it actually performed the same, but it was frustrating to use and wasted 15 minutes every time you needed to switch the settings. This one also works in the CW and CCW directions without having to adjust anything.

GREAT product design. I really like this tool. Comes with a nice blow molded, custom fitted, plastic case. The case has with what appears to be a substantial clamp. You can display torque readings in newton-meters(N-m), foot-pounds or inch-pounds. It uses one CR2032 coin battery and will auto shut-off after 60 seconds of no use. I own 4 different mechanical torque wrenches (3x Precision Instruments and 1x Sears Craftsman). I estimate I have spent over $500 for these wrenches - including the occasional calibration. The cost to calibrate one of these wrenches can run from about $60 on up to almost $100. So, paying for just one calibration of a mechanical torque wrench costs more then buying one ARM602-4. Therefore, I believe his tool represents a great value. The published accuracy for the ARM602-4 is 2% in the CW direction. My best Precision Instruments torque wrench is 3%. The big disadvantage with the ARM602-4 is its size - it will not fit in similar tight places that a mechanical ratchet torque wrench can fit. When I received my ARM602-4, I checked my other torque wrenches. I have a relatively new ( a couple of years old) Precision Instruments 1/2 inch split beam that agrees well my ARM602-4. But when I checked my old Sears Craftsman 3/8 inch, I found it was WAY off (but it has been almost 10 years since I had it calibrated). Yes, it is not evident which tool will have the most accurate torque measurement - but I think it safe to assume that a brand new ARM602-4 will have been recently tested for calibration. I work as an engineer on new product development (but I spend my spare time wrenching). I believe the product design team hit it out-of-the-park on this design. Durability? I can not say yet - I have only had it about one month. But of course, I would not kick it around on the garage floor. But I do not kick my mechanical torque wrenches around either. With the twist grip style torque wrenches - if you drop them when the spring is not tight - you could knock them out of whack. And then you would be looking at a new calibration. Torque wrenches - including this tool - should be handled with much more care than any standard ratchet or wrench. I have had nothing but problems with the click mechanism sticking on my Precision Instruments 3/8 inch wrench. EVEN after Precision Instrument "repaired" this wrench in 2014. So I appreciate the fact that the ARM602-4 does not have any mechanism that clicks and releases. One thing I have learned, since I purchased this tool - is to SLOW down when attempting an accurate torque setting. This ARM602-4 can quickly capture a peak torque value. So if you quickly snap tighten your click style mechanical wrench you will see more of a difference in readings. I believe the difference can be explained by your technique and the fact that humans have a much slower response than electronics. By the time you feel the click and stop tightening your mechanical torque wrench - you can easily overshoot. So, I have learned to slow down - and I can now achieve much better agreement between a recently calibrated mechanical torque wrench and this electronic torque tool. This has been a great purchase for me. I has me re-thinking the value of mechanical torque wrenches. If you do most of your torque settings where you have adequate clearance (like engine builds with the engine mounted to a stand or wheel lugs) the ARM602-4 maybe a better choice then buying one of the old, unreliable mechanical click style torque wrenches.

These torque adaptors work great and are accurate. I have one in two different toolboxes.

I bought this based on all the existing recommendations. The Torque Test Channel sort-of-reviewed a competing digital torque gauge product from a no-name brand and said it was good; this ACDelco version was only a little more expensive and labeled with a recognized brand. I have confidence in the torque readings and they match my click-type torque wrench pretty closely. The unit itself feels pretty durable. Uses lithium coin-cell batteries, which is smart for cold-weather function. Can't speak to battery life as I just bought it.

Pros I purchased the ACDelco ARM602-4 1/2" digital torque adapter primarily to check the accuracy of my four other click-type torque wrenches. It is carefully made and everything fits together nicely. The tiny machine screws that hold the battery cover on screw into brass inserts molded in the plastic so it would be extremely unlikely to strip them out. Embossed into the cover is the battery type used: 2032. The control buttons are slightly recessed and not so easily mashed when in use and it seems to be very accurate. However, while I do not think it would stand up to daily use of a professional mechanic, it feels solid. Being electronic it IS more fragile than a click-type torque wrench. Cons The display is recessed and must be viewed straight on to be able to read it and probably unreadable in the dark confines of an engine compartment, this tool needs a back light. The three indicator LED lights get washed out in daylight. In a noisy shop with a radio playing it would be almost impossible to hear the beeper. The instruction manual is marginal at best that has missing words forcing you to try to interpret the meaning. The commands for setting up the adapter are not intuitive so keep the manual handy. Would I buy this again? Maybe. My main gripe is the display and that needs a backlight.

Seems to be accurate and was very helpful to calibrate my other torque wrenches