Thread: Hole Opener Set

"I mean, how bad can they be?" A cunning idea, but not if the the cutters are made of Chinesium*

*a valuable alloy of foundry floor sweepings and bakelite.

I have a much larger set of carbide Forstner bits made in China. Most of them are really great. A few of them have a problem with the centre point being off centre but I usually pre drill a pilot hole anyway so it isn't a problem, and you should not be running these at anything faster than a few hundred RPM in any event.

Originally Posted by GraemeCook

SWMBO was doodling on her iPad and suddenly asked me: "Do you have a hole opener set?"

That's nice ! .
I like it when the girls ( Wife + two daughters) get involved and ask me about stuff like that.
Their funny.

One day my SWMBO walks into my shed and says "do you want these things?"
She shows me a huge Orange box. I open it , Its a double layered Japanese set of Taps and Dies. Old but not used much and complete.

I'm like "What! where did you get these. "

Someone had cleaned out a shed and dumped all sorts of mechanics tools on the footpath for collection by the council . It sat there for weeks. Half the stuff was taken by people first though. My wife just happened to be one of the first.

Those "Hole openers" Look good . Cheap enough too. What are the sizes?

Originally Posted by auscab

... Those "Hole openers" Look good . Cheap enough too. What are the sizes? ...

I think sizes are 15, 20, 25, 30 and 35 mm - here is the original advertisement:
Woodworking Hole Opener Set Positioning Hard Alloy Flat Wing Drill Adjustable Hinge Hole Expander 15-35mm (with Wooden Box),temu

When I read the thread title I was imagining something to enlarge existing holes which I have need of on a reasonably regular basis. It's easy enough if I can hold the work-piece in the drill press vise and centre the existing hole, but can be an awkward exercise if I can't, and the hole centre happens to be critical. So my curiosity was piqued, but it turns out someone has just been a bit careless with translating the word for "drill bit".

My comment would be that since Forstner bits are really for use in a drill press and most drill presses have a depth stop of some sort, providing individual depth stop collars for each bit seems a bit superfluous to me. I suspect most will find them more of a nuisance than a help.

My collection of Forstners has been acquired piecemeal over about 40 years and includes several of doubtful parentage that are a bit softer than they should be. They are not too hard to sharpen (excluding the 35mm carbide-tipped bit bought for installing hinges), and suffice for the amount of use I have for them, but if you need to use them every day, & particularly for hard woods, I'd recommend skipping the budget brands & proceeding to the better quality versions straight up...
Cheers,

Hi Ian

For enlarging holes - star M type bits, gimlets or spoon bits are useful to have - they have chamfer tips and will self centre on a hole- (as well as easy to use on angle)-

If some manufacturer was smart and produced a bit like those that instead of a center point cutter they had a spigot , say a 5mm rod sticking out the middle, 5 or 7mm out . Then a drill press wouldn't be needed. You'd just drill a 5mm hole where you want your 35mm hole . Grab the 35mm spigot bit and electric hand drill it in what ever direction your 5mm hole goes if you want. The drill bit stops where your 5mm pilot hole stopped or goes right through if your pilot hole does.

When I needed large holes like roughly 63 mm for building my workbench, I made a spade bit with 5mm spigot. Just some old leaf spring ground with spigot then welded onto some 1/2 inch rod. A good fast cheap way of getting a big hole. It was used in my drill press. It took less time to make it that driving to Total tools and back would have taken me . And who knows what a such a large bit would have cost? I made a second bit to drill the hole for tapping the 62mm threads as well . Around 50mm I think.
I don't know if such drill bits exist to buy? How would people drill a hole if they needed it between 50 and 100mm wide?
Ive got forstner type bits that will do up to something like 75mm but they fit into a mill type machine. A drill press on steroids.

I'm about to drill two 60 or 63mm holes in a day or two. That doesn't happen very often.

Originally Posted by auscab

If some manufacturer was smart and produced a bit like those that instead of a center point cutter they had a spigot , say a 5mm rod sticking out the middle, 5 or 7mm out . Then a drill press wouldn't be needed. You'd just drill a 5mm hole where you want your 35mm hole . Grab the 35mm spigot bit and electric hand drill it in what ever direction your 5mm hole goes if you want. The drill bit stops where your 5mm pilot hole stopped or goes right through if your pilot hole does.

When I needed large holes like roughly 63 mm for building my workbench, I made a spade bit with 5mm spigot. Just some old leaf spring ground with spigot then welded onto some 1/2 inch rod. A good fast cheap way of getting a big hole. It was used in my drill press. It took less time to make it that driving to Total tools and back would have taken me . And who knows what a such a large bit would have cost? I made a second bit to drill the hole for tapping the 62mm threads as well . Around 50mm I think.
I don't know if such drill bits exist to buy? How would people drill a hole if they needed it between 50 and 100mm wide?
Ive got forstner type bits that will do up to something like 75mm but they fit into a mill type machine. A drill press on steroids.

I'm about to drill two 60 or 63mm holes in a day or two. That doesn't happen very often.

Rob

I liked that improvisation for your large spade bit.

A hole saw is similar to what you are describing, but only works if you are drilling right through. There are large forstner bits available. I have two or three, one of which came in a clock making kit.

I once had to drill a number of holes through the end grain of a 150mm Grey Box cylinder (end grain in a hardwood like this is particularly difficult as you probably know) . They were the timber shrouds between the treads for the central steel tube in a spiral staircase. I used one of these:

Super Drill & adaptor pack Large metal drill bit - Robson's Tool King Store

While they are primarily intended for thin steel, they also work well on timber. Like a Forsner bit there is no real automatic chip removal because of the absence of flutes so you either have to rig up a vacuum system or blow out the chips with an air gun, if you drill much below the depth of the cutter. I had to use an extension piece to drill to the 150mm depth. From memory the pipe was about 50mm (maybe 60mm) but the super drill (Brand name) system will work up to about 75mm. Bore a 25.4mm hole first and insert the appropriate cutters. Metal workers use a similar principle with a fly cutter on even larger diameters.

I thought I had better check the sizes and it turned out that all three large bits were 80mm:

P1090046 - Copy small.jpg

And while I was at it, the super drill.

P1090049 - Copy small.jpg

Somewhere I have that set of "hole openers," which was the start of this thread, but I couldn't put my hands on them quickly.

Regards
Paul

Originally Posted by auscab

When I needed large holes like roughly 63 mm for building my workbench, I made a spade bit with 5mm spigot. Just some old leaf spring ground with spigot then welded onto some 1/2 inch rod. A good fast cheap way of getting a big hole. It was used in my drill press. It took less time to make it that driving to Total tools and back would have taken me . And who knows what a such a large bit would have cost? I made a second bit to drill the hole for tapping the 62mm threads as well . Around 50mm I think.
I don't know if such drill bits exist to buy?
How would people drill a hole if they needed it between 50 and 100mm wide?

To answer your how would ... question

This circle cutter can cut up circles up to about 200 mm diameter.

If I had to make a hole larger than what a large diameter Forstner bit can cut, or one that was a different size, I'd look at using a router fitted with a top bearing cutter, and use the circle cutter to make a template for the router to follow.

Nice Forstner bits Paul . I didn't realize they came as large as 80 mm . Ive never searched for them . I do have some old style large ones around that size, I'll put a picture down below.

The Super drill looks sturdy .

The adjustable type like that and the one Ian showed Ive only considered good enough for light thin cutting. I suppose if you went slow and light you would get through though.

I'm thinking of 50mm and thicker drilling.

I tested this 2.5 inch cutter today on some 50mm Oak before I drill the 2 x 50mm thick Oak table base ends I'm building atm .
It was a bit smoky. The sides are rubbing to much so I'll grind them back a bit.

IMG_3685a.jpg

Originally Posted by auscab

I tested this 2.5 inch cutter today on some 50mm Oak before I drill the 2 x 50mm thick Oak table base ends I'm building atm .
It was a bit smoky. The sides are rubbing to much so I'll grind them back a bit.

IMG_3685a.jpg

Rob

I suspect the heat is because there is nowhere for the sawdust to exit. Try drilling down , say 20mm, then remove the cutter and drill two small holes right through (13-20mm) just inside the circumference of the hole made with the big cutter. If the timber is raised a little, it will give somewhere for the sawdust to fall. I have not tried this with timber, but it is a technique used with hole saws to cut thick metal which is greater than the depth of the teeth.

Regards
Paul

Originally Posted by IanW

My comment would be that since Forstner bits are really for use in a drill press and most drill presses have a depth stop of some sort, providing individual depth stop collars for each bit seems a bit superfluous to me. I suspect most will find them more of a nuisance than a help.

True that they're best in a drill press, but when you're making holes for Blum type hinges in cupboard doors on site these would be very handy.

Certainly a lot handier than masking tape or a texta mark on the side of a Forstner bit with only a millimetre or two between success and punching the point of the Forstner bit through the immaculate glossy finish of the face of the usually expensive or not easily replaceable door.

Originally Posted by 419

True that they're best in a drill press, but when you're making holes for Blum type hinges in cupboard doors on site these would be very handy.

Certainly a lot handier than masking tape or a texta mark on the side of a Forstner bit with only a millimetre or two between success and punching the point of the Forstner bit through the immaculate glossy finish of the face of the usually expensive or not easily replaceable door.

Yairs, that would be a rather nasty surprise, for sure! Fortunately, I've only had to drill hinge sockets with the drill-press, I'd be a very nervous chappie doing it 'freehand". However, I don't think the bits posted by the OP would drill too many holes in melamine-coated chipboard, do you? Maybe buy a set for the depth-stops alone - just one door saved would pay for the set...

Cheers,

Originally Posted by Bushmiller

Rob

I suspect the heat is because there is nowhere for the sawdust to exit. Try drilling down , say 20mm, then remove the cutter and drill two small holes right through (13-20mm) just inside the circumference of the hole made with the big cutter.

Thanks Paul Ill try that. Before I tried it out I thought the shavings would have been flying up those ramps.
But no , it was smoking so bad I could hardly see the machine in front of me.
IMG_3685aa.jpg
The sides were rubbing but like you say it must have been the sawdust. I did grind a little off the sides angled in from the cutting edge so that wasn't changed and it still did the smoke trick the second time. There must be some trick needed like pre drilling or these bits wouldn't be used. Or maybe they have been sharpened wrong and the leading edge of those ramps are not cutting deep enough in and removing wood properly? There is evidence of a fair bit of hand filling to the cutting edges on the bottom.
Someone went to a lot of work making them . I"m not sure that it was Wadkin that made for the LQ borer and recessor though which is the machine the set came with. They would have stamped Wadkin on them. The shanks on them are 3/4" to give an idea of the sizes. Its the first time Ive needed to use one of them .

LQ bits.jpg

Rob