What tool drills this type of hole?

  • Context: Construction 
  • Thread starter Thread starter tirelessphoenix
  • Start date Start date
  • Tags Tags
    Hole
Click For Summary

Discussion Overview

The discussion revolves around the tools and techniques needed to create a specific type of hole, characterized by a funnel shape around it, suitable for ensuring screw caps sit flush. Participants explore various tools and methods for countersinking holes in different materials.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants identify the hole type as a countersunk hole and suggest using oversized bits or countersinking tools.
  • Others mention the importance of knowing the material and thickness when selecting the appropriate tool for countersinking.
  • A few participants note that different countersink bits have varying angles and flutes, which can affect their suitability for different materials.
  • Concerns are raised about the quality of tools, particularly for harder materials, and the potential for jiggly holes if not used correctly.
  • One participant shares a personal experience related to drilling and countersinking in a home repair context, highlighting practical challenges faced during the process.

Areas of Agreement / Disagreement

Participants generally agree that a countersink is the appropriate tool for the described hole, but there are multiple competing views regarding the specifics of tool selection, material considerations, and the implications of different countersink angles. The discussion remains unresolved on the best approach for various scenarios.

Contextual Notes

Participants mention that the effectiveness of countersinking tools can vary based on the material being drilled and that some tools may not perform well in harder materials. There are also references to the need for careful handling and technique to avoid issues like jiggly holes.

tirelessphoenix
Messages
36
Reaction score
7
TL;DR
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
special.jpg
 
Last edited by a moderator:
Physics news on Phys.org
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.
 
  • Like
Likes   Reactions: Nik_2213, Lnewqban, BillTre and 1 other person
woooaww guys! this is amazing!! getting the answer so quick! this is grrreat!! THANK YOU so much!!!
 
  • Like
Likes   Reactions: Lnewqban, BillTre and berkeman
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?
 
  • Like
Likes   Reactions: Lnewqban and 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:
1713909423151.png


There are also different kinds of those bits (different angles and different #s of flutes) to better accommodate different materials.
 
  • Like
Likes   Reactions: Nik_2213 and Lnewqban
berkeman said:
Yep, one of the most used drill bit kits in my woodshop. :smile:
Yep, me to. I have the exact same set plus a different older one (that is less precise)
 
  • Like
Likes   Reactions: berkeman
tirelessphoenix said:
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
 
Lnewqban said:
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”.
 
  • Like
Likes   Reactions: Nik_2213 and Lnewqban
  • #10
Lnewqban said:
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.
 
  • Like
Likes   Reactions: Lnewqban
  • #11
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...
:wink: :wink: :wink:
 
Last edited by a moderator:

Similar threads

  • · Replies 14 ·
Replies
14
Views
7K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 26 ·
Replies
26
Views
5K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 26 ·
Replies
26
Views
3K
Replies
8
Views
11K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
2
Views
2K
  • · Replies 51 ·
2
Replies
51
Views
5K
Replies
14
Views
3K