Angle grinder blade(s) for cutting rebar

Question

I have tried both thick and thin blades for cutting rebar. The thick one takes forever and is like smelting a sword. The thin one gets the job done but the blades I selected - limited choices at local hardware store - disappeared after a couple of cuts.

My preference would be to spend more for a good blade with the following characteristics:

• relatively thin so that the amount of material grinded away is less
• but long lasting
• will not disappear causing lockup of the nut (i had to toss away my first grinder for that reason)

Do these types of blades exist? Most of them seem to be 6mm: I'd want 3 or less.

Note: there are two quite different needs:

• cutting rebar to a desired length in a shop - with proper clamps and any leverage I want
• cutting rebar inside retaining wall blocks that sometimes have significant accessibility challenges

For the second case it is critical that the tool be short length. Also I need to be able to cut as flush as possible

Update I did order this diamond tipped cutoff 1.5mm blade (which @Monkeyzeus had also mentioned in an earlier comment)

I also posted a separate question on how to replace/remove the blade in a locked up angle grinder How to replace grinder / cutoff wheel blades

source: https://www.amazon.com/gp/product/B07Q2B1TBP/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 .

Will report back after delivery.

Answer 1

if you want to cut with an angle grinder use a cutting disc (also called a cut-off wheel) they are typically from 3 to 1mm thick. The thin ones are better because they cut faster.

For longer blade life try using lighter pressure

Answer 2

I used a metal shear or rebar cutter.

Quieter, quicker and no electricity required.

Answer 3

For cutting rebar, I use 0.040 cutoff discs. Light pressure gets me through 1/2" rebar in about 30 seconds.

Use a blade guard. These can break, but I have probably made 300 cuts in rebar in the last year, and I cannot remember breaking a cutoff disc.

If you can put the work into alignment of the thinner disc, not only will the rebar cut faster, but it will be cooler for handling after the cut.

Broken discs and locked nuts on the shaft are readily dealt with. The easiest approach is impact. I use an adapter to the nut on a standard 1/2" impact tool. Can be air, electric or hammer driven. The hammer driven ones are small and fit in almost any tool bag.

Since I have about 15 grinders, I have several different types of nuts. They fit into two categories: Hex nuts, and pin nuts. The pin nuts have round holes and some have hex holes. For the hex holes I simply use the right sized hex (Allen) tool on a socket mount. Usually 1/4" but I have one which is actually 6mm. For the pin ones, I have a old 1/2" drive socket which I welded 1/4" pins to. For the hex nuts, I just use the right sized socket, which is usually 13/16"

In the field, it takes perhaps 90 seconds to use a hammer impact and loosen the nut. In the shop it can be faster. However, it is very infrequent.

And just a final point, inertia is your friend. Do not use the shaft lock pin when using impact. No need to stress the internal gearbox locking pin. Let inertia be your friend.

Answer 4

My actual solution is along the lines of the comment by @MonkeyZeus and the accepted answer. After much research - and learning about the cut-off blades - I selected a diamond one and also got a more powerful grinder from a name brand Bosch. The results are quite good: a dozen rebars at about sixty seconds a pop. More importantly is the small and portable form factor - to the extent of a long series of extension cords being portable. I had a steep slope to do a bunch of rebar cutoffs and was able to grind down to within 1/4 inch of the ground and/or concrete with maximum six inches of clearance in any direction.

Bosch Angle Grinder

Diamond cut off blade

Note It was very difficult to loosen the grinder clamp nut on this blade after use. I almost gave up.