I purchased this to retrofit the installation for a built-in barbeque grill. It required cutting a 10"X36" notch out of a rock veneer wall with steel wire reinforcement and multiple heavy gauge metal framing elements. This blade cut through them all and is not showing significant wear. Yesterday I had to cut about 1" off the end of a 3" X 8" X 26" sandstone plank. This blade went through it in about 2 minutes. I had to finish the last bit with a diamond grit Sawzall blade but the diamond circular blade goes through material about 10 times faster so it makes the entire job quick. During the grill installation I needed to cut a 1.5" thick granite slab about 12" long by 3" on each side of the grill. This blade made those cuts in under 5 minutes. I still needed the sawzall diamond blade to clean up the inner corner but the circular 70 made 95% of the cut in less time than the sawzall needed to do the 5% cleanup.NOTE: Do not be fooled into buying an expensive cement saw unless you need to do a lot of cutting. I used a circular saw I picked up for $16 on amazon and it worked great. Yeah the dust will kill the bearings but for occasional use I would be surprised if I didn't get another 80 hours of cutting out of the cheap saw. I found that for detailed and cleanup work it is very helpful to also have a 4.5" diamond blade for a standard angle grinder which cost me $19. I also found that some cuts were too difficult to reach with circular saws or grinder so I used a 8" long diamond grit Sawzall blade that cost $13 and a cheap Sawzall that cost $19. Without all three tools the job would have been difficult.My only complaint is that it is easy to loose the brass spacer and it fell out of the center the first time the blade was changed. It is not a serious problem but you do need to manually place the brass spacer before placing the saws support washer. I used a large ziplock bag to keep the saw blade and the spacer together for the next job.