Mystery…..

[Grumpy21]

How come when you take the gearbox tunnel out and carefully put all the brass set screws and funny washers carefully in a container there’s less in the container than you took out? Somehow I’ve ’lost’ 6 washers and 4 screws! It’s a mystery.

[Sleeper]

Gravity...

John

[geoberni]

Not a problem I've had.
Something like that I get a piece of cardboard, mark out the shape of the panel and then push each fastener through the card in the corresponding place to it's neighbours.
Old trick from working on aircraft where a panel with perhaps 20-30 fasteners might have up to 7-8 different lengths, depending on the thickness of supporting structure each individual fastener was passing through before engaging with it's anchor nut...

[Chief]

Tinworm for steel.
Brassworm for brass

The fun is when after putting everything in the container, you then put your hand/foot on the edge, and away they roll.......

[RustAndMagic]

The funny washers pulled a prank on you

[Grumpy21]

I made a post in the wanted section.

[Wes]

Thats odd as i usually have stuff left over!

[King Kenny]

The same thing happens to spanners. I'm working under the car, perhaps adjusting the clutch linkage, and `i'm using a 1/4 whitworth spanner. I put it by my side for a second to use a 5/16th spanner. When I reach down to pick up the 1/4 inch, it's gone! I then spent three quarters of an hour looking for it.

[mike1864]

For disappearing Biros, check out the Biroid planet theory in Douglas Adams' Hitchhikers Guide to the Galaxy.
Perhaps there are similar planets for washers and spanners to gravitate to.