3" hole Mild Steel 3/8" thick

[tapwelder]

I'on kno wat hapent?

[ronsii]

me ther..???

[Fnord5]

I'll let you borrow this, but you need to record video of it.

[geezer]

Well i want to apologize to all who posted recommendations/suggestions. Indeed we cut holes in the sq tubing with carbide tipped hole saw and 1/2 inch drill. Took our time and it worked fine, nice clean cuts. I will try and post pick or two. Much obliged

[bubmiller]

A 3 inch hole saw can get stuck.


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[Sberry]

cutting horizontal is good, chips fall out and I am not against using a little water and fully grasp the concept of this being one off in nature. Even if the saw was disposable the cost isnt a deal breaker.

[Weldalittle]

A 3 inch hole saw can get stuck.


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you would think they could have come up with a better emergency operator safety system.

[bubmiller]

you would think they could have come up with a better emergency operator safety system.

Like an idiot operator shutdown sensor? I actually figured the gears were the weak spot, never guessed it was the handle.

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[bubmiller]

Back to topic, I don't have the resources of a machine shop, so I use hole saws regularly in heavy metal. I usually drill a hole in a block of wood first, then clamp it in place as a guide instead of using a pilot bit.

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[danielplace]

A regular quality bi metal hole saw will easily do it fairly quickly if there is only one to do no problem. Slow and clean chips out often. Maybe use air to blow it clean and keep teeth clean. Cutting oil will help keep teeth clean, cool and cutting. Good steady pressure at slow speed and keep saw making chips. Any hint of loading up stop and clean it again.

Anytime I use a hole saw the arbor drill bit has been replaced with solid rod. Never use bit in hole saw to make the pilot hole. Use a separate bit to drill pilot hole then the solid rod in hole saw will keep hole saw guided straight and not woller out your pilot guide hole. The diameters are more accurate and cut is straight and clean.

[smithdoor]

Nice drill 2 piece type.

Dave

you would think they could have come up with a better emergency operator safety system.

[Bob]

I don't think there is any cutting oil better than good ol, kerosine. It's been used for over a hundred years now.

[William McCormick]

Friend of mine ask me if I could make a hole in a cast steel column sq and 3/8" thick. I immediately thought of my torch. But he would like to have a clean 3" hole and I do not believe i can do that with oxyacetylene. Would a hole saw and going slow work? He would like a clean cut. Thanks

If you have a drill mag you can easily do it. I use bees wax to lubricate the hole saw. I cut really nice four inch holes in 1/2” steel I make a lot of them with one hole saw and bees wax. You can do it by hand too with a nice slow hand held drill and bees wax. On smaller holes you can get through in under five minutes with a slow hand drill motor.



Sincerely,

William McCormick

[farmersammm]

Don't guys drill a hole where the saw kerf runs? Something about allowing the chips to clear the hole saw instead of building up.

[davec]

Don't guys drill a hole where the saw kerf runs? Something about allowing the chips to clear the hole saw instead of building up.

I have, mainly on thicker stuff. On something like 1/8" it isn't thick enough to become an issue but even 1/4" thick is enough where you either have to stop frequently to clear out packed chips, or you drill the extra hole which allows you to keep going longer.

[William McCormick]

Don't guys drill a hole where the saw kerf runs? Something about allowing the chips to clear the hole saw instead of building up.

Over the years I have found that doing something like that sometimes helps and sometimes hurts. I cut for about 20 seconds and retract the hole-saw clear the chips, and touch the teeth and sides of the hole-saw with the bees wax and cut some more, once the teeth are below the surface. That has proven to be the fastest. The other method can sometimes introduce a spot that causes debris to jam and take off teeth.

Sincerely,

William McCormick

[Lis2323]

Over the years I have found that doing something like that sometimes helps and sometimes hurts. I cut for about 20 seconds and retract the hole-saw clear the chips, and touch the teeth and sides of the hole-saw with the bees wax and cut some more, once the teeth are below the surface. That has proven to be the fastest. The other method can sometimes introduce a spot that causes debris to jam and take off teeth.

Sincerely,

William McCormick

I used to have a switchable magnetic base holding a regulated pressure air nozzle with shut off to direct a stream of compressed air at the hole saw’s kerf.

It worked really well but it got disassembled when I needed the base back for my dial indicator.

I’ve always meant to purchase a cheapo import base but I think its time to try William’s beeswax.


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[12V71]

I used to have a switchable magnetic base holding a regulated pressure air nozzle with shut off to direct a stream of compressed air at the hole saw’s kerf.

It worked really well but it got disassembled when I needed the base back for my dial indicator.

I’ve always meant to purchase a cheapo import base but I think its time to try William’s beeswax.


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I just used a welding magnet and a needle valve with a chunk of 1/4" brake line aimed in the right spot. I would like to try it with a water mist.

[Lis2323]

I just remembered. I used a small knob type flow control valve to throttle the flow and act as a shut off.


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[Sberry]

Best thing ever for a bit of water in a fab shop is a gallon weed sprayer.

[Weldalittle]

Best thing ever for a bit of water in a fab shop is a gallon weed sprayer.

I've been using a 1/2 gallon sprayer for autobody work the whole past week! Great for wet sanding, and rinsing before blow gun. I have a couple gallon ones, but what's been through them is questionable... They're great when a garden hose isn't available. Wow, I'm getting off-topic...

[Sberry]

The other method can sometimes introduce a spot that causes debris to jam and take off teeth.

Yes, I ruined one a while back on a 062 alum tube, a 3 inch. It caught and ripped teeth right out, would have never thought of it before it happened.

[William McCormick]

Yes, I ruined one a while back on a 062 alum tube, a 3 inch. It caught and ripped teeth right out, would have never thought of it before it happened.

Yea, any tubular or unleveled penetration will ruin those things in seconds. I think I had drilled a hole in the wrong spot with like a 2 1/2” hole saw and my plan was to cut a three inch hole in a piece of wood that I would clamp down to the part a half inch off center, to move the new hole over a half inch. It started off great then it jammed and I lost the hole saw. I was able to finish it but I had to recut the hole because the new hole saws teeth were wider than the old hole saw. Just one of those days.


Sincerely,

Wiliam McCormick

[Lis2323]

Yea, any tubular or unleveled penetration will ruin those things in seconds. I think I had drilled a hole in the wrong spot with like a 2 1/2” hole saw and my plan was to cut a three inch hole in a piece of wood that I would clamp down to the part a half inch off center, to move the new hole over a half inch. It started off great then it jammed and I lost the hole saw. I was able to finish it but I had to recut the hole because the new hole saws teeth were wider than the old hole saw. Just one of those days.


Sincerely,

Wiliam McCormick

The rest of us NEVER have any of those


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[Sberry]

Yes, it was in a tube, was a small tube and as you said, uneven. I was on a run nut not under a delusion that it wasnt gonna grab at some point but that soft tube rippem right out of the saw. I think I might have saved it in scrap, didnt occur to me that it might even still work fine on steel. I have cut those sized before and not above doing it for one off or prototype but under 2 inch really cuts rather well.
I did one on this job where I lay a hole out off by exactly 1/2 inch. It was 3/8 plate. After I fot over the duh moment cleaned up the plug and welded it back in both sides and recut the hole and didnt bother it a bit.