If you're filling your correctly sized hand luggage bag with lead, then as long as you can carry it without showing discomfort then it's unlikely (well probably 0 chance) that it will be checked for weight. I assume you're not simply transporting lead, so in that case to pack 23 kg in a hand-size luggage seems unlikely and if your luggage is obviously oversized then expect problems.

It seems you're likely going to struggle with the dimensions of the hand luggage rather than the weight which i've never seen checked.

As for combining size and weight for 2 hand luggage as 1, then that's only a question AF can answer, I don't expect anyone has tried that before.