XCr.
The jewel of the crown. A biphasic stainless steel drawn seamless from a solid billet — the only tube family of its kind in the bicycle industry. It does not ask for paint, and it does not ask for forgiveness.
the numbers.
Figures from the Columbus 2024 steel catalogue. Test bars, not marketing bars.
| 1450MPa | ultimate tensile strength — the load at which the steel finally lets go | UTS |
| 1000MPa | yield strength — where it would begin to remember a bend | YS |
| > 10% | elongation at break, measured on Ap5 | AP5 |
| 0.4mm | minimum wall thickness across the set | WALL |

from a solid billet.
“Most stainless tubes begin as a rolled sheet and a welded seam. XCr begins as a solid bar of steel.”
Each XCr tube is machine-perforated from the billet and cold drawn countless times, down to walls of 0.4 mm. No seam, no weak line — just a biphasic microstructure with exceptional resistance to stress corrosion cracking, in every use and every weather.
Polished, it needs no paint and no clear-coat. The surface is the finish.
- Structure
- biphasic · martensitic
- Drawing
- seamless · cold
- Surface
- Ra < 0.4
- Butting
- triple & double
welded or brazed.
“A material is only as good as the joint it allows.”
XCr TIG-welds with APX4S filler and brazes with T99 — a silver alloy of 56% Ag, 22% Cu, 17% Zn. Excellent weldability was designed in, not discovered later; the ultra-smooth Ra < 0.4 surface leaves the builder nothing to apologise for.
- TIG filler
- APX4S
- Braze
- T99 · AG 56%
- Finish
- polished · raw
DRAWN INTO — the XCr tubeset →