What size is this Screw?

[fishkeeprian]

Hello, the bottom leveling screw broke off my Two little fishes 150 phosban reactor. I contacted them and sent me the attached drawing. I ordered some M3 nylon screws but they are to small. What does M3/16 mean, I'm from the UK so I may have misunderstood this drawing.

 

[Vinny Kreyling]

Screw is 3 mm diameter 16 is the thread.
in the US it would be threads per inch, in the UK ?
A good hardware store should be able to match the drawing.

 

[mcgyvr]

I ordered some M3 nylon screws but they are to small. What does M3/16 mean, I'm from the UK so I may have misunderstood this drawing.

It means nothing.. Its not a correct thread size designation in either the US(SAE/ANSI) or Metric standard.

A "typical" M3 screw has a .5mm pitch

In the US we specify threads per inch but for metric you specific a thread pitch (spacing between threads)
One would not specify a thread as M3 with 16 threads per inch..

Are you not able to just take the broken piece or reactor to a hardware store and match up the threads with a nut or screw there?
Thats what I always do when I don't know the exact size/designation..