Easy Removal of Mill Scale

I've seen many suggestions for getting that annoying mill scale off the steel parts. From Patio cleaner requiring several hours of soaking, to using Flap Discs to grind it off. I tried the flap disc approach and was amazed how much time it takes to get through that scale and when you do break through, unless you are extremely careful, the abrasive disc starts to remove the steel too, resulting in scores to the surface you wanted to preserve.

The answer is polycarbide discs. These load into an angle grinder just like the flap discs, but that's where the similarity ends.
These polycarbide discs cut through mill scale like you wouldn't believe. I cleaned up both sides of a Horn Plate to shiny steel finish in less than 10 minutes. Other benefit is that they don't gouge the steel.
Readily available from outlets like Screwfix (83915) and Tool Station (18114). Other brands available !!

These should save you hours of frustration. Enjoy.

Agreed, I've been using these too.

Sometimes even these have trouble so my technique ended up being a quick soak in patio cleaner - about 15 minutes, and then a quick going over with one of these.

They're also good for when you just want to take a very small amount of metal off, for example to smooth joints or smooth sharp edges without taking too much off.

Do you know the up to date codes for Screwfix or Toolstation?

I'd say they are talking about these
https://www.toolstation.com/abracs-poly-abrasive-disc/p22693