Construction What tool drills this type of hole?

[tirelessphoenix]

TL;DR Summary

Special hole with funnel-like around it

I need replicate a hole that has some kind of 'funnel' around it (see picture attached, arrows), so that screw caps get completely flat once they go through it, without protruding. Does anyone know what type of tool is needed to accomplish this? thank you

 

[Averagesupernova]

That is a countersunk hole. An oversized bit can work if you are careful and not too fussy. Google countersinking tools and you should come up with several solutions.

 

[berkeman]

That is a countersunk hole.

Yep, one of the most used drill bit kits in my woodshop.

https://www.amazon.com/FTG-Maximum-Torque-Adjustable-Countersink/dp/B07PQ9X9T4/?tag=pfamazon01-20

 

[tirelessphoenix]

woooaww guys! this is amazing!! getting the answer so quick! this is grrreat!! THANK YOU so much!!!

 

[Flyboy]

As others have mentioned, it’s a countersink. There’s a couple tools that you can use to get that result, depending on the situation.

Do you know what material(s) it’s being put in, and their thicknesses?

 

[phinds]

Also, if you already HAVE a hole and just want to add the countersink (what you call the "funnel") you can use a pure countersink bit:

There are also different kinds of those bits (different angles and different #s of flutes) to better accommodate different materials.

 

[phinds]

Yep, one of the most used drill bit kits in my woodshop.

Yep, me to. I have the exact same set plus a different older one (that is less precise)

 

[Lnewqban]

I need to replicate a hole that...

Not all these tools have a similar angle.
Not critical for soft wood, but important for drilling metal and other hard materials.

Please, see:
https://en.m.wikipedia.org/wiki/Countersink

 

[Flyboy]

Not all these tools have a similar angle.
Not critical for soft wood, but important for drilling metal and other hard materials.

Please, see:
https://en.m.wikipedia.org/wiki/Countersink

Yep. Aviation and general purpose countersinks are very different critters. I don’t recall the different angles off the top of my head but they’re not even close enough to go “eh, good enough”.

 

[sophiecentaur]

Not critical for soft wood, but important for drilling metal and other hard materials.

Read the details on the advert. Some cheap tools claim to be harder than they are. Good drills are not cheap but it may not matter for a one-off job in a soft material.
Fix the workpiece well and use oil and a slow drill speed or you can get a very jiggly hole.

 

[Nik_2213]

Slightly off-topic, I'm repairing my kitchen's brick wall deranged by replacement of dead, floor-stood c/h combi-boiler by wall-hung. I'd have first stripped all that wall's century-old plaster and layered tiles back to bare brick, fitted plaster-board / sheet-rock and smiled. No, the 'insurance job' guys just made a ghastly mess.
Fairs' fair: Not fitter's fault that his core-drilling flue hole found an un-documented power cable buried in plaster, requiring extensive excavation to identify route: Think 'Time Team' and 'Trench One'...

(Personal Observation: Such old plaster and proximity to extensive copper piping thwarts cable-sniffers...)

In places, I've through-plugged new battens to bare wall --5 or 6mm pilot, then 8mm and blow clean-- warily counter-sinking 8mm holes in batten so long wall-plugs and their screw-heads lay flush, grip better. In others, I've had to craft local 'pattress' by grafting an extra piece to side of batten.

Whatever, 'Dire Lord Murphy' guarantees there's often a sufficiently nasty knot exactly where you must drill, or side-graft cannot be screwed lest that blocks 'surface-box' fixing....
So, deploy jigged 8mm spur-drill, grooved 8mm dowels, wood-glue, press to place, wait to set, saw/file even.

Soon learned that 'modest' counter-sink on such 'rough' holes allowed for narrow, but beneficial glue moat...