Determining screw size (replacing screw in furniture feet)

I am trying to determine what screw size I need for some replacement furniture feet.

I took off one of the old screw in feet and used a gauge to measure it - the screw fit tightly through the 4.8 gauge hole (turns out this is a drill bit gauge!)

How do I determine what screw size to buy based on the gauge?

Apologies if this is a dumb question but I've tried Googling for an answer and over an hour later I'm still none the wiser

 

I'm at work at the moment, I'll take one when I get home

 

Apologies for giant photos

The feet are on bar stools, they are plastic which has screws through into threaded metal screw holes in the two layer base.

 

I was hoping to replace them with something like this (in the right size of course) https://www.amazon.co.uk/dp/B00H4YG...UTF8&colid=3Q5I03N4T49MD&coliid=I4XFVKJOBVZLP (white because they won't mark the light kitchen floor tiles)

 

I should have thought to take them into Screwfix or Selco (just around the corner! LOL) to see if they could match the screws. It's mainly the plastic part of the foot that needs replacing though. My worry is that if the plastic does not sit proud of the screw head, the screw heads could still scratch the floor tiles (that's why I thought the Amazon ones might be a safer option)

 

The ones from Vital Parts look good apart from they only come in black which might mark the floor tiles :/

 

Thanks Chippie - I'll hunt them out tomorrow

 

Yup, they fit tightly into the 4.8 hole of a drill bit gauge (the flat plastic kind) and are approx 15mm long. (the stools are pretty old and probably from the USA, I bought them second hand)