Smart Weigh CW-50G Carbon Steel 50g OIML Class M1: ± 3 mg Calibration Weight with Chrome Finish

There is really no point to use a calibration weight if the actual weight is not its nominal weight. OIML Class M1 is not just a geeky set of letters and numbers. It is the difference between a calibration weight that is useful to calibrate one of the "0.01 gram" read-out scales that Amazon sells and a weight that is not useful for that purpose.Recently, we purchased from Amazon an  Etekcity 500g Digital Pocket Scale, Stainless Steel, Backlit Display, Tare, Hold and PCS Features, 0.001oz Resolution . We also ordered a 500g calibration weight (-not- a Smart Weigh calibration weight), needed to calibrate that scale. Not paying sufficient attention -- our fault -- the calibration weight that we ordered was not an OIML Class M1 weight. (If it had been an OIML Class M1 weight, the 500g weight would have been accurate to plus or minus 0.025 grams, or 25 milligrams.) When we placed that nominally 500g weight on the nominally 500g capacity scale, the scale's display read O_Ld (overload). When we attempted to calibrate the scale with that same weight, the scale's calibration program never completed its cycle, even though we allowed it 24 hours to do so. (We have a separate review of the Etekcity scale under Amazon's listing for that scale, where more detail of our testing may be seen.)The website for Fisher Scientific has a downloadable PDF file (produced by Mettler Toledo) that lays out the tolerances for the OIML classes of weights. You need to consult that table (or one similar to it) to determine what OIML class of weight you need to calibrate a scale with a specific level of precision. We consulted that table and determined that we needed an OIML Class M1 weight to calibrate a scale with a maximum capacity in the range that we were looking for to a precision of 0.01 gram. (0.01 gram equals 10 milligrams.) We purchased this Smart Weigh calibration weight because we wanted to calibrate a scale that -reads- in 0.01 gram increments to be -accurate- within 0.01 gram.What a difference there was between our prior experience with the 500g capacity scale and 500g calibration weight and our experience when we used this Smart Weigh CW-200G OIML Class M1 calibration weight to calibrate a scale with a 300g maximum capacity. When we placed this Smart Weigh 200g calibration weight on the platform of a new but not recalibrated  ONE - My Weigh DuraScale D2 300g x 0.01g Digital Scale w/Rubber Case - Tough! , the display read 200.11 grams; after we calibrated the scale with the Smart Weigh calibration weight and then zeroed the display and placed the calibration weight on the scale, the read-out was exactly 200.00 grams. That -perfect- result was repeatable on several test tries. Using the same scale to weigh an uncirculated U.S. nickel, the display read out 5.00 grams, confirming that the calibration was correct.The OIML Class M1 specification is the spec that tells you that the calibration weight can be used to calibrate a scale with a maximum capacity similar to the capacities of the scales that we tested with 0.01g precision; accept nothing less.

I couldn't believe my scale was accurate! It has been knocked down, in toddler hands and more! To ship I need to know what the ounces and pounds are. I don't have a gram option so I should have bought maybe a different weight. So we weighed and I got a different number...went out line to a conversation chart an yes, it was accurate.☆ I like how the weight is protected inside a plastic cased that has a foam inside as an added measure of security / protection!○ I suggest if you buy this to have a scale that has the gram option as well. My error on picking this one but it works.☆○☆○☆ I TOOK IT TO MY LOCAL POSTAL OFFICE TO BE SURE ITS WEIGHS CORRECTLY AND IT DOES!

When I first got my Smart Weigh Calibration weight, I was cleaning it and a flake of metal came off the top edge. It was very thin, but this obviously alters the weight of a CALIBRATION WEIGHT.I should have returned it ASAP. I still have it and use it, but the accuracy of its weight will forever be in question.

This review is for the 100 gram weight. I used this to calibrate a counting scale which is accurate to 0.01 grams, and the counting scale delivers perfectly accurate results every single time. I have no reason to doubt that these weights are accurate. When I also placed this company's 300 gram weight on the scale (after calibrating with this 100 gram weight), it read 299.98, which is well within the advertised margin of error. Just in case you find that concerning, understand that the smallest and lightest Lego pieces weigh approximately 0.12 grams, and these weights are accurate to within 0.02 grams. That's pretty darn accurate.

Ok.. I like this little scale. Seems accurate (I bought the calibration weight and calibrate before every use). My only gripe, and my fault I suppose, it won't weigh 10 troy ounces...a troy ounce being heavier than a regular ounce. I didn't know that. Learn something new every day. FYI

WYSIWYG. Used a high-end calibration weight to see how close this was - pretty near dead on, and plenty good enough for keeping my scale trued up for espresso extraction.

I had a friend check it on their professional scales, it came out on the mark, now I know that I can properly calibrate my scale. Love the protective storage case included.

Plastic case a nice feature but wish it had been threaded. Only other minor gripe is that the finish job could have been a little more, but the accuracy is right on, as I checked it out on my lab balance that's accurate enough to weigh mosquito balls. Not a bad deal, at all!

Excellent customer service. Having received an empty package from Amazon (the weight had clearly fallen out of the cardboard envelope) I was sent another free of charge by Five Star after already obtaining a refund on the empty package. The weight I received is very good quality finished in chrome and packaged in a handy container to keep the calibration weight clean and free from scratches etc. Would highly recommend both the weight and especially Five Star for the level of customer satisfaction.

This calibration weight is excellent. It is acurate within a tolorance of 0.001 and works excellenty with my scales. I would buy this again, but I don't think I will need to as this product is so strong it is likely to last the rest of my life. And then some.Purcahse this for Smart Weigh scales.

I ordered this to calibrate my digital scales, not knowing which weight was required for that model I followed Amazon's recommendation (customers who bought this also bought x). Unfortunately not the best recommendation as when the scales arrived, a 500g weight was required. I had to get another calibration weight (obviously) but am keeping this as it will come in useful for checking the scales' accuracy.

I purchased this when I need to calibrate my Smart Weigh SWS100 elite scale (please see my review on Smart Weigh scale). Its a must to keep scale calibrate to ensure accuracy of weight.. It is packaged in protective snuggly cylinder case and I have used it already to ensure scale is accurate following transportation.

Came in a padded plastic container and as far as I can tell is the correct weight (500g)Was purchased along with the Smart Weigh scales and used to calibrate same.Only gave it 4 stars instead of 5 as it will now lie about in a cupboard for a long time and in truth I could have got by without it.Did its job though.