How to cut concrete block with a circular saw

Question

I have some concrete blocks that are 4 inches by 6 inches. I need to cut them in half at a 45 degree angle. Can I do this with a circular saw and a masonry blade ? I would also make a jig to cut the 45s. I only need to make 4 cuts.

I checked with a few rental places but it would be expensive to rent a big saw. I live far enough from any rental places that it would be a full day rental. Also it would seem difficult to make a decent 45 degree cut with a large demo saw.

My thought is to make a jig to hold the blocks and make the cut and use a circular saw with some type of masonry diamond blade. A 7" blade looks to be in the 20-30 dollar range.

Would this work ?

Answer 1

If you can find the same size arbor (hole in the blade) it works great. A thin blade uses less horsepower but won’t last as long. Make sure to blow the dust out of the motor after done as it will shorten the motor life if left in the motor. I do this with a table saw and skill saw for brick and cinder blocks when I want a clean cut. Also wear a dust mask you dont want to breathe the dust.

Answer 2

Masonry blades should cost $3-5 each. Maybe you're referring to a diamond-dust blade. I'd use the standard fiber type, depending on how many cuts you need to make. If more than a handful, diamond may be the way to go.

Rather than setting your saw at a miter, leave it at 90 degrees and cut from the side of the blocks. You'd have a very hard time keeping a miter cut flat. Cut in several steps, say 3/4 to 1" at a time.