Circular saw blades

[SHADOWFOX]

I've been using my Ridgid cordless circular saw for the past year or so and I love it. I recently got a deal on a SKIL HD77 worm drive saw and I looked at the blade and it had a diamond cutout to fit the diamond shapr arbor on the worm drive saw.. Went to look at circular saw blades and most of them have a round hole but did notice an etched diamond shape I guess to fit saws with diamond shape arbor. My question is how easy is it to removed these to get the diamond shape hole on the blade? Do they easily snap out? What do you use to take it out? Appreciate any info.

Thanks,

[LCHIEN]

I've never done it before, but I think it's a "knockout" - you use a punch to knock it out.

[LarryG]

Yes, it's a knockout. I usually lay the blade on something so it's supported around the arbor hole, and hit the knockout with the claw of a hammer.

Expect to hand that 77 down to your grandkids. I bought mine circa 1974. Still going strong.

[mikel]

I use a nail set ( big one )or a whole punch I make sure the blade is supported well. I use a piece with a 1" whole drilled in the center. I like the board to be smaller than the teeth so it sits flat on the side of the blade.
You don't want to bend the blade.

...m