QWORK Plastic Tubular Spring Scale - 1N, 5N, 10N, 20N, 30N Capacity, Grams & Newton Calibration, Zeroing Capability, Clear Plastic Body Spring Balance Hanging Tube, Set of 5

I needed to test tension and torque on several machines, with a variety of small and large ranges (200 grams to > 1kg). I tried a digital luggage scale for the large ranges but it was annoying since they are programmed to lock the measurement after a peak is detected. These spring scales are perfect for the job, since I can easily see the change over time and make a mental note of the peak when I find it. (If you've ever tried to understand a changing value using a digital multimeter, you'll get what I mean. An analog needle is so much more informative than a bunch of flickering digits.)I tested these scales with a range of weights (confirmed on other calibrated digital scales) and they were all close enough to be useful for me (within a few percent). The key to accuracy is selecting an appropriate scale range for your test: None of these will be accurate on the extreme low end of the range, so don't test a 50g weight on the 3kg scale. There are 5, so it's easy to find one that fits.The top of each scale has a zero adjustment, just turn the screw. The spring tension inside can be adjusted non-destructively (although you'd need some well-calibrated equipment to do so) and they were calibrated at the factory, not just assembled and shipped. The construction is decent. The clear tubes have some scuff marks but the markings are clear. The assembly stays together naturally since it's all hooks and gravity. The blue rings at the bottom of the tubes are press-fit (and maybe glued?) to the tubes, so you can take them apart if you wanted to. They have no effect on the measurement, just keeping the dust out.Overall, I'm impressed!

These are cheap and plastic but good. Careful adjusting the zero using the cap on the top! Tighten and if the marker doesn't move up then pull down firmly on the scale hook. It will reset then you can re-adjust. To verify accuracy, a new US nickel is 5 grams exactly. Toss a few in a baggie. I weighed 17 of them and the 100 gram scale read just under 85. So +/- 1 gram on the low scale. I like how they have different scales for different weight ranges. This is a big plus for accuracy. Just be sure to be weighing around the middle part of the range.Not often I get a cheap product that works reasonably well. I weigh objects to measure center of mass and inertial torque approximations. these work well as long as what you're weighing is less than 5 pounds.

I did not pay attention to the varying sizes when purchased but they work well for my science students

Ordered a variety pack of 5. Two of them looked used. They were a little scratched but otherwise usable. I was using them for a school science project and will end up in the fishing tackle box, so it is fine for that.

Perfect kit for educational use or an at-home experiment. The different resistances allow for a variety of measurements. Each comes in its own box. It allows for adjusting the zero point. Smooth spring motion.

Instead of buying an expensive tool to measure the tension of my embroidery machine thread I purchased this product. I couldn't be happier. It worked great and my embroidery machine is running perfectly. This product is very durable and accurate . Thanks so much!

Its in the headline

Perfect for home school lab projects for force & weight. Durable enough to last for several projects, but not too complicated for tweens to use.