C 10X30 vs PFC 260×90
C 10X30 is an C section from the American AISC Shapes Database; PFC 260×90 is the closest equivalent in the European (Continental) range. C 10X30 carries more bending: 437.53 cm³ of plastic modulus against 425 cm³, 2.9% more. PFC 260×90 is the lighter of the two at 34.8 kg/m against 44.6 kg/m, a saving of 28.2% on steel weight. PFC 260×90 is deeper, 260 mm against 254 mm, which matters where the floor zone is tight.
| Property | C 10X30 C | PFC 260×90 PFC | Difference |
|---|---|---|---|
| Mass | 44.6 kg/m | 34.8 kg/m | +28.2% |
| Depth | 254 mm | 260 mm | -2.3% |
| Width | 77 mm | 90 mm | -14.4% |
| Web thickness | 17.1 mm | 8 mm | +113.8% |
| Flange thickness | 11.1 mm | 14 mm | -20.7% |
| Area | 56.8 cm² | 44.4 cm² | +27.9% |
| Second moment, major (Iy) | 4,287 cm⁴ | 4,728 cm⁴ | -9.3% |
| Plastic modulus, major (Wpl,y) | 437.53 cm³ | 425 cm³ | +2.9% |
| Elastic modulus, major (Wel,y) | 339.21 cm³ | 364 cm³ | -6.8% |
| Second moment, minor (Iz) | 163.6 cm⁴ | 353 cm⁴ | -53.7% |
| Plastic modulus, minor (Wpl,z) | 61.943 cm³ | 102 cm³ | -39.3% |
| Radius of gyration, minor (iz) | 1.7 cm | 2.82 cm | -39.7% |
| Torsion constant (It) | 50.78 cm⁴ | 20.6 cm⁴ | +146.5% |
C 10X30 to AISC Shapes Database v16.0; PFC 260×90 to Continental Steel. Difference is expressed relative to PFC 260×90.
How to choose between them
On stiffness, PFC 260×90 has the larger second moment of area: 4,728 cm⁴ against 4,287 cm⁴, a difference of 9.3%. This matters more often than the strength comparison, because on normal floor spans deflection rather than bending capacity sets the beam size - so if the two are close on modulus but apart on inertia, the stiffer one is usually the better answer even when it is not the stronger one.
Measured as bending capacity per kilogram of steel, PFC 260×90 is the more efficient section: 12.2 against 9.8 cm³ per kg/m, 19.7% better. Over a floor of repeated beams that difference is real tonnage, though it is often outweighed by whichever section the fabricator can actually source.
The two diverge much more about the minor axis: PFC 260×90 has 102 cm³ of minor-axis plastic modulus against 61.943 cm³, 39.3% more. If the member sees any minor-axis bending, or if it is unrestrained over a long length and lateral-torsional buckling governs, that gap decides the comparison even though the major-axis numbers looked equivalent.
These come from different catalogues, so treat the swap as a design change rather than a like-for-like substitution. C sections are specified to AISC Shapes Database v16.0 and PFC to Continental Steel; the steel grades, tolerances and available lengths differ, connection details and bolt gauges are set out differently, and the two are rarely both stocked in the same market. Check availability before changing a section on a drawing to save 28.2% weight.
In short, C 10X30 is the stronger section and PFC 260×90 is the lighter one; where those are the same section, it is the clear choice, and where they are not, decide on whether your design is governed by capacity or by tonnage.