How to make neat holes in thin aluminium lid

[Beanwood]

I have to make 5 neat (Round?) holes in a cosmetic tin lid.
The tin is made of very thin aluminium (0.2mm I think) and the lid is 37mm across. I want each of the holes to be about 7mm, but that measurement's not vital. They must however be smooth edged (They are for dogs to sniff, and I don't want their noses scratched)
If I try to drill them, the drill catches, and wrecks the edge.
If I try taking a punch to them on a wooden surface, the aluminium distorts.
I'm sure there's an obvious way to do it, but I don't know what that is.
(I need to do 6 or so of these every month or so)

Can anyone enlighten me please?

 

[James1979]

Top die and bottom die in a flypress?

Use your punch but make a bottom die for it so it supports the material more than wood?

Sandwich the sheet between two bits of ply and drill through the lot?

If it’s that thin, what about a hand held single hole punch. Like what bus conductors used to use?

 

[MetalMonkey]

What about a whitney hand punch (or clone)

 

[500e]

Sharp punch on to hardwood block Or as @MetalMonkey said or @James1979

Pardon our interruption...

 

[Screwdriver]

I have to make 5 neat (Round?) holes in a cosmetic tin lid.
The tin is made of very thin aluminium (0.2mm I think) and the lid is 37mm across. I want each of the holes to be about 7mm, but that measurement's not vital. They must however be smooth edged (They are for dogs to sniff, and I don't want their noses scratched)
If I try to drill them, the drill catches, and wrecks the edge.
If I try taking a punch to them on a wooden surface, the aluminium distorts.
I'm sure there's an obvious way to do it, but I don't know what that is.
(I need to do 6 or so of these every month or so)

Can anyone enlighten me please?

Use a small piece of folded rag, drill through that for perfect hole and no lifting….

 

[George A2Y]

Same as James 1979, except the top could be a pre-drilled template (steel/aluminium) with the 6 holes in it.

 

[RichardM]

I find that if I use wood to act as a backing piece to drill into the drill grabs on the grain, I get a better hole finish backing with nylon or polythene block. Personally I would try a sharp punch as suggested before.

 

[Onoff]

3D print some edge protectors and glue them on?

 

[Master-of-none]

Protect the hole edges and create a smooth rounded opening by fitting eyelets / grommets https://www.amazon.co.uk/eyelets/s?k=eyelets

 

[Paul.]

I used to do exactly this on a job that was made from 22swg ally sheet, all you need is a hollow gasket punch and a hard polyethylene block, use a new part of the block for each hole, wood is too soft and will distort and burr the hole, or not cut it cleanly. then to clean up the block just use a wood plane to restore the surface.

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[tom2207]

maybe use an eyelet kit , then you would get a safety edge too .

 

[gordon stephenson]

Use a small wad punch, Supported on hardwood end grain etc, Punch downover and the holes will be slightly recessed and smooth.

 

[jsf55]

Drill a block of steel in your pillar drill making sure it's well clamped, remove drill and grind the "blunt" end flat and replace in drill, now don't start it up but gently push down on the lever and it will pierce it easy

 

[Agroshield]

Or...

Would that work if the lid has a flange on it typical to most lids?

...remove drill and grind the "blunt" end flat

That might be a bit of an ask for 7mm. If you slightly hollow ground the end (deeper in the middle), it could work to your advantage.

----

My suggestion: find a marble of the correct size, go up somewhere really high, let it go. Aim well.

 

[jsf55]

It's only 0.2mm aluminium ?

 

[Beanwood]

The collective never fails to amaze me. I was a bit worried asking, as it didn't involve gas cutting or a plasma - but I think you've nalied it.

Use a small piece of folded rag, drill through that for perfect hole and no lifting….

I have to try this, as it just seems too easy.

I used to do exactly this on a job that was made from 22swg ally sheet, all you need is a hollow gasket punch and a hard polyethylene block, use a new part of the block for each hole, wood is too soft and will distort and burr the hole, or not cut it cleanly. then to clean up the block just use a wood plane to restore the surface.

Experience of doing what I need -brilliant. This appeals, as I already have a punch set much like your link.
This is another one I'll try once I find some polyethylene. Does it leave any distortion at all - I ask as that would dictate if I can just lay the top flat on the board (Punching from the 'in' side, , or if I have to make a round mount to fit inside the lid lip to punch inwards. Cleaning up the face with a wood plane is inspired. Thanks.

Drill a block of steel in your pillar drill making sure it's well clamped, remove drill and grind the "blunt" end flat and replace in drill, now don't start it up but gently push down on the lever and it will pierce it easy

Another good suggestion - a perfectly sized hole, so no chance for distortion. Once set up, I could also do this in an arbor press, which appeals. Thanks.

 

[Screwdriver]

I have to try this, as it just seems too easy.

old machinists trick, surprised no one seems to know it.

The rag jams up the flutes so the workpiece doesn’t get dragged up the bit.

 

[fizzy]

A step drill is great on thin sheet and doesn't grab.

 

[Beanwood]

A step drill is great on thin sheet and doesn't grab.

Good shout!! I should have thought of that one.

 

[James1979]

In the interest of curiosity and being a helpful sort of soul ()….

It’s the thinnest I’ve got and it’s titanium at just over 0.5mm so not especially helpful but it gives an idea