A hardline run is designed around one number: how far a tube can turn before it fails. PETG bends without the hazing that shows up in cheaper acrylic, and this tube holds a 35 mm minimum radius — tight enough to clear a pump top or a memory stick without a fitting on every corner. Get that radius right and a run can be planned, cut and rebuilt from a drawing instead of guesswork.The wall is 2 mm, which keeps the inner bore at 10 mm — the same flow area as our flexible runs, so switching to hardline costs nothing in pump performance. Each tube arrives cut to 1,000 mm with both ends chamfered, then polished until the surface reads like glass; a scratch-free tube seats deeper into a compression collar and seals on the first turn. Four tubes per pack cover a CPU and GPU loop with enough left for a mistake.