If the rest of the mass properties you see on that page (especially Volume = 43329.41 cubic millimeters and Surface area = 17024.68 square millimeters) are the same as his, the only reason it may show a different weight is if the Material Properties of plain carbon steel are slightly different in your version of Solidworks and his. These values are sometimes (but rarely) updated by the company, thus making an exact model have slightly different values related to that material. However, if the Volume and Surface Area I mentioned are different than his, then your model is not exactly like his. Those properties are of the model itself, not related to the material. They would be the same whether the material was copper, cast iron, stainless steel, wood, etc. I use Solidworks 2023 currently (like his) and my mass properties are exactly what he showed. I hope that helps.

This is a pretty common "error": like what was mentioned in the SOLIDWORKS livestream, it's common to have a problem with fillet/round selection order. Originally, I had the exact mass as you using 2023, but when I looked at the fillets/rounds on the isometric of the drawing, I realized 2 of them didn't match-up in appearance. You made the part correctly, but you didn't put the fillets in the right order. Odds are, the problem was where the 2mm fillets and rounds meet between the small side piece and the top surface.

@@mauriciocastillo7302 I just saw your answer here to the OP and I'm trying to figure out how the problem you described is possible. Try as I may, no matter in what order I select to apply fillets, the part's properties are always the same in the end. You mentioned "common error" and "Solidworks livestream" but Solidworks says you will only receive an error when trying to apply a fillet to two perpendicular lines where the fillet radius is greater than one of the lines (like trying to machine a 50mm fillet in real life on a part that's only 20mm, essentially) They make no mention of the "order" and I can't replicate it. Can you tell me how to do so on the part in this video? You mentioned the 2mm fillet where the piece meets the top but I've changed those time and again and it still turns out correctly every time.

​@@thinking-monkey Yeah, it it can be difficult to create recreate a scenario where the fillets don't match up, and if you have "shaded with edges" turned off, then it can be impossible to figure out. It's not just a problem in SOLIDWORKS as I've encountered a similar problem in Inventor (I had to select the fillets in a specific order (through trial & error as there were a lot) or the command wouldn't work. Also, I couldn't simply unselect in Inventor as the command would just break for me). I'm not exactly sure what goes wrong, but it seems to be common for parts that have a lot of fillet/round intersections; in this case, we have 1-3 fillets, and 1-2 rounds intersecting/meeting between the top surface and the side piece (These numbers depend on the order you selected your fillets/rounds in). You can find the "error" mentioned in the SOLIDWORKS video titled "LIVE at 3DEXPERIENCE World 2023 - Day 3" at the 4:43:35 mark where it's briefly mentioned that people had problems with fillet order. While they don't say exactly what it is, I'm very confident it is what I mentioned. The fillet error you mentioned could've also been another problem, say they forgot to change it to 2mm, but in that case, it typically doesn't let you finish the command, a subsequent command, or it looks obviously wrong. I don't think most people know about this as the fillet command nearly always works as intended, and most parts/practice parts usually don't have a lot of intersecting/meeting fillets/rounds. I recreated the part in a way that I think most people would've made it, then I tried different selection orders, coming to three different masses: 338.02, 338.27, and 337.97. In all three cases, the difference is in the same spot. When you closely inspect the 338.27, 337.97, and the Phase 1 drawing's isometric, you will notice that on the 338.27, while it looks the same (and exactly the same when show edges is turned off if you don't look even closer), there is an interruption on the round of the top surface (noted by the visible phantom lines) compared to a smooth, uninterrupted round for the 337.97 & Phase 1 isometric. Lastly, for the 338.02, there is an evident difference in shape, and the intersection isn't smooth. If you want the file to see exactly how I ordered the fillets in all three case, and to see how the difference in selection has on the part, I can send it to you somehow. I changed the colour of faces of the fillets/rounds that differ between selections (noted by their blue colour) so it can be easy to spot, and you can simply switch between the three configurations.

Dear sir what version of Solid work which you have used?