Need a 4 1/4" hole saw

[newood2]

What's a decent(not too pricey) name brand 4 1/4" hole saw. I need to cut at least 24 holes in 3/4" MDF for some blast gate that I'm building.
Milwaukee has the 49-56-0221 for $17, but can it cut at least 24 holes before it gets dull.
I was thinking of using a jigsaw and a router, but that's too much MDF dust. The reason for the 4 1/4" cutter, it's the same diameter as the OD of the S&D pipe I'm using for the gates.
I credit this forum for the idea on building these gates.

Howie

[Pappy]

You didn't say what you are making them from. Assuming it's wood or MDF, i would use one of these.

http://www.hartvilletool.com/product/11355

[newood2]

You didn't say what you are making them from. Assuming it's wood or MDF, i would use one of these.

Pappy, I edited and repost before your reply, so my
question hopefully make more sense.

Howie

[Pappy]

I would still go with the circle cutter on a drill press.

A hole saw is going to give you one size, and you arent likely to need a 4 1/4" hole very often after this. Also, if the saw size and pipe o.d. aren't an exact match the gate will be either too loose or too tight.

With the circle cutter, you can make a few test cuts and dial in a good tight press fit. You also have a tool that will make different size cuts when you need them.

[cgallery]

I would still go with the circle cutter on a drill press.

A hole saw is going to give you one size, and you arent likely to need a 4 1/4" hole very often after this. Also, if the saw size and pipe o.d. aren't an exact match the gate will be either too loose or too tight.

With the circle cutter, you can make a few test cuts and dial in a good tight press fit. You also have a tool that will make different size cuts when you need them.

I had one of these once. The problem I had was that the cutting bit got hot enough to destroy the heat treating. I was young and probably trying to go too fast.

[lrogers]

Using either tool will generate a lot of heat unless you take it slow and suck the dust out of the kerf continously. Again, with either tool, make sure you have your stock clamped securely to the drill press. I have used both tools and both will do the job, but as Pappy pointed out, the adjustable tool will give you greater flexability.

[Andrew Benedetto]

Use some bees wax(candle) or stick band saw lube(HD) on the hole saw and as said go slow, clear the dust. I would use a drill press at the lowest speed too. That adjustable cutter will not last long in mdf. The hole saw is Bi-Metal at least. Lennox are better, Lowes has them.

[Holbren]

These are the plans a friend of mine used and his work well.

http://www.benchmark.20m.com/article...ebuilding.html

[JimD]

I use cheap HF hole saws and adjustable hole cutter. For the blast gates it was the hole cutter. It burns and doesn't go fast but if you are patient it will give you the size hole you need. If you are doing 24 holes you can afford to spend the time getting the adjustment down.

Jim

[WayneJ]

I just passed the hole saws in HD before and remembered your post .The hole saw is $35 and if you need the arbor thats another $15. Seems a bit pricey, a little over two bucks a hole.
Wayne

[dlminehart]

If you have a bandsaw, and a 1/4"-1/2" bimetal blade to hold up under the MDF, you can easily make a jig to quickly cut out the holes. It'll require gluing up the access slot from outer edge of MDF to the circle it contains, but that's no biggie. If you don't have a bandsaw, this project alone would get you toward making its acquisition worthwhile!

[Thom2]

Personally, I'd use a fly-cutter to make a template to use with a 1/4" straight bit and a bushing ..... probably a 4 5/8" hole in the template, then use a 1/4" straight bit and 1" OD bushing on the template. I think my math holds out there (I'm known to use more error than trial)

Anyway, using the router would make the 24 holes quick, easy and painless ... template would take a little time to work up to exactly the right size, but this is the method I would use.

Or, use a fly-cutter to get a perfect hole in a piece of 3/4 mdf and then use a top bearing pattern bit to cut duplicates.

[LCHIEN]

Personally, I'd use a fly-cutter to make a template to use with a 1/4" straight bit and a bushing ..... probably a 4 5/8" hole in the template, then use a 1/4" straight bit and 1" OD bushing on the template. I think my math holds out there (I'm known to use more error than trial)

Anyway, using the router would make the 24 holes quick, easy and painless ... template would take a little time to work up to exactly the right size, but this is the method I would use.

Or, use a fly-cutter to get a perfect hole in a piece of 3/4 mdf and then use a top bearing pattern bit to cut duplicates.

If I had to make twenty-four of them, this is the approach I would take, too.

[newood2]

Personally, I'd use a fly-cutter to make a template to use with a 1/4" straight bit and a bushing
.

I've already made a 4 1/4" template with 3/4" MDF using a S&D end cap(for $1.25 at HD) as a guide. Using a jigsaw, I cut out to within 1/8" of my circumference. I then place the cap underneath and use a 1/2" trim bit(router) to cut the remaining 1/8". The bit follows the inside edge of the cap.
My problem is, this takes too long and too much dust. For 1 or 2 holes thats fine, but for 24 I"m thinking a hole saw would be quicker and less dust.

Howie

[LCHIEN]

I've already made a 4 1/4" template with 3/4" MDF using a S&D end cap(for $1.25 at HD) as a guide. Using a jigsaw, I cut out to within 1/8" of my circumference. I then place the cap underneath and use a 1/2" trim bit(router) to cut the remaining 1/8". The bit follows the inside edge of the cap.
My problem is, this takes too long and too much dust. For 1 or 2 holes thats fine, but for 24 I"m thinking a hole saw would be quicker and less dust.

Howie

Don't bother with the jigsaw. Just drill a 3/4" hole about 1/8" from the circumference, Drop the pattern bit thru the hole and cut sidewyas until the bearing hits the template. Then with the bearing against the template, just go around the hole closely-doesn't matter if you don't keep it tight to the template. Then finish with a fast pass or two to clean it up nice and pretty. Should go pretty fast.