Profiles
CalcSteel ships 640+ section sizes from four standards — Brazilian (NBR 6355 cold-formed C and U, plus solid round bar R), American AISC (W, hollow sections HSS, single angles L), European EN (IPE, HEA/HEB/HEM, hollow sections, angles), and Indian IS 808 (ISMB/ISHB, ISMC, ISA) — plus any custom section you define.
Assigning a profile to the selected bars commits three things the solver and the code-check depend on: the cross-section geometry (area and inertias), the manufacturing process (hot-rolled vs cold-formed, which selects the verification standard), and the rotation angle (which axis resists bending).
Hot-Rolled vs Cold-Formed — the category that picks your design code
The material-category tab at the top of the Profile panel decides which design standard verifies the bar (the panel offers hot-rolled, cold-formed, aluminum and stainless tabs). It is the highest-stakes choice on this page: a section can look right and still be checked under the wrong code.
Hot-rolled
Thick material rolled hot, with a generous fillet radius (r) at the web-flange junction. Local buckling rarely governs, so the full section can reach yield (often the plastic moment). Verified by NBR 8800 / AISC 360 / Eurocode 3 (EN 1993-1-1) / AS 4100 / IS 800.
Cold-formed
Thin sheet of constant thickness press-braked at room temperature, with sharp corners and a return lip added to stiffen each flange edge. Thin walls buckle locally and distortionally before yield, so effective-width methods apply. Verified by NBR 14762 (AISI S100 / EN 1993-1-3 are the international equivalents).
⚠ Common mistake
Modeling a thin cold-formed section but checking it as hot-rolled is unconservative — the cold-formed code subtracts the capacity lost to local buckling that the hot-rolled code ignores. CalcSteel keeps a separate design standard per material category, so choosing the cold-formed tab routes the check through NBR 14762, not NBR 8800.
Strong Axis vs Weak Axis — orientation changes capacity
Every section has a strong axis (x-x, larger Ix) and a weak axis (y-y, smaller Iy). The rotation angle you assign decides which one lands in the plane of bending — the single most common modeling error is laying a beam on its weak axis.
At 0° the section bends about its strong axis; at 90° the same section bends about its weak axis. For a typical W or IPE, Ix is several times Iy, so a 90° rotation cuts bending stiffness and capacity by the same order. Practical rules: orient the deep dimension into the plane of bending, and brace columns about their weak axis, since the smaller of rx / ry governs their flexural buckling.
The Profile panel exposes four discrete angles — 0°, 90°, 180°, 270°. 90° swaps the bending axis; 180° and 270° mirror the section (used to flip a channel’s lip/flange direction) without changing its capacity.
Reading the Annotated Cross-Section
The panel and the catalog detail page draw a fully dimensioned section with an orange dashed centroid (CG). Here is what every symbol means and which dimension field it maps to.
Hot-rolled W — h, b, tw, tf
Cold-formed C — h, b, t, lip
h— total depth / heightb— flange widthtw— web thickness (W / I)tf— flange thickness (W / I)t— uniform wall thickness (C, U, RHS, SHS, CHS, L)lip— edge stiffener — C sections only⌀— diameter (round bar R / CHS)r— fillet / corner radiusThe orange dashed crosshair is the centroid (CG) — it marks the two centroidal axes. For bending in a given plane the axis across it is the neutral axis: fibres on one side stretch, the other compress, and stress is zero along it; the distance from the CG to the extreme fibre sets the section modulus. Cold-formed C / U carry tw = tf = r = 0 in the catalog, which is why no web/flange-thickness labels appear on a channel — only the uniform t.
Choosing the Right Family
Each family answers a different structural job. Pick by the load the member carries, not by what is on hand.
WWide-flange beams (I / H)High inertia-to-weight — the default for beams and columns in bending.h, b, tw, tfCLipped channel (C)Cold-formed purlins, girts and studs; pairs back-to-back for built-up members.h, b, t, lipUPlain channel (U)Secondary framing and back-to-back chords without an edge stiffener.h, b, tRHSRectangular hollowClosed section — high torsional stiffness; columns and bracing.h, b, tSHSSquare hollowNear-equal stiffness both ways (Ix ≈ Iy); columns and posts.b, tCHSCircular hollowIdentical inertia in every direction and best torsion; exposed/architectural members.d, tLAngle (L)Truss web members, bracing and light ties (single angles load eccentrically).h, b, tRRound solid barSolid round — tension rods and ties only.dWhich Families Ship per Standard
Family availability depends on the chosen standard, so you don’t hunt for an angle in the Brazilian catalog (it isn’t there) or a channel in AISC.
| Standard | W | C | U | R | RHS | SHS | CHS | L |
|---|---|---|---|---|---|---|---|---|
| BR | ○ | ● | ● | ● | ○ | ○ | ○ | ○ |
| AISC | ● | ○ | ○ | ○ | ● | ● | ● | ● |
| EN | ● | ○ | ○ | ○ | ● | ● | ● | ● |
| IS | ● | ○ | ● | ○ | ○ | ○ | ○ | ● |
| UK | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ |
Takeaway: the Brazilian catalog ships cold-formed C / U / R and has no angles — single angles (L) come from AISC / EN / IS. UK is reserved in the standard list but ships no static profiles yet. The in-app family chips are populated per material category from the database, so the live filter can show more than the offline catalog emits.
Section Properties and the Limit States They Govern
CalcSteel computes these from the geometry and shows them (SI and imperial) on every profile’s detail page. Each one maps to a real limit state:
| Property | Symbol | Governs |
|---|---|---|
| Area | A | Axial capacity (tension yielding) and self-weight |
| Second moment of area | Ix, Iy | Flexural stiffness and deflection (δ ∝ 1/I); buckling |
| Elastic section modulus | Sx, Sy | Elastic moment capacity (M = S·f) |
| Plastic section modulus | Zx, Zy | Plastic moment for compact sections (Mp = Z·fy) |
| Radius of gyration | rx, ry | Slenderness λ = KL/r → flexural buckling; the smaller governs an unbraced column |
When comparing two candidate beams, compare Sx (strength) and Ix (deflection) per unit weight — not depth alone; the full computed table lives on each profile’s detail page.
Built-Up / Double Sections
When a C, U or L is selected, a mode row appears in the panel: C / U offer Back-to-back (][) and Box ([]); angles additionally offer Quad arrangements. The preview prefixes 2× and shows the listed weight doubled, and a Gap (mm) field sets the clear spacing — gap 0 means the pieces touch. Built-up sections raise the inertia about both axes: a 2L back-to-back is the classic truss chord, and a boxed channel makes a stocky compression member.
2×C back-to-back
2×C box
4×L quad
Custom Profiles — dimensions in, weight auto-computed
Click the Custom (+) button to define a section CalcSteel doesn’t ship. The form shows only the fields that family needs, and the weight is computed for you (never typed) from the cross-sectional area using the outer-perimeter ("développé") method at a density of 7.85 g/cm³:
- C: A = t·(h + 2b + 2·lip)
- U: A = t·(h + 2b)
- RHS: A = 2t·(h + b)
- SHS: A = 4t·b
- CHS: A = π(d² − (d−2t)²)/4
- L: A = t·(h + b)
- R: A = π(d/2)²
- W: A = 2·b·tf + (h − 2tf)·tw
Honest limits: the density is fixed at 7.85 g/cm³ (carbon steel), so a custom stainless or aluminum section would be given steel mass; the cold-formed area uses the outer-perimeter (développé) method (it ignores corner-radius shortening), a faithful fabrication-style estimate rather than a CAD-exact value; and the custom form applies no fillet radius, so the W fillet term is not added in practice. The custom section is registered and assigned to the selected bars in one action and supports the same rotation and double/quad modes.
How to Assign, Orient & Create a Profile
- 1Select one or more bars in the 3D scene (click, or drag a box selection).
- 2Open the Profile panel from the toolbar.
- 3Pick the material-category tab — it sets the verification code (hot-rolled → NBR 8800 by default; cold-formed → NBR 14762).
- 4Pick a family chip, then search by name (type "IPE 200" or "W360" to jump straight to it) or scroll the list — each row shows its live weight in kg/m.
- 5For C / U / L, optionally enable a double / built-up mode and set the gap.
- 6Set the rotation angle (0° / 90° / 180° / 270°) to put the right axis in the plane of bending.
- 7Click Apply to assign the profile to all selected bars — or click the Custom (+) button to enter dimensions for a non-catalog section (the weight auto-fills).
Tip: a selected profile shows a live dimensioned preview before you apply, so you can confirm the orientation and built-up mode first.
References
- NBR 6355 — Brazilian cold-formed structural shapes (dimensions)
- NBR 8800 — Brazilian design of hot-rolled steel structures
- NBR 14762 — Brazilian design of cold-formed steel members
- AISC 360 — American specification + Shapes Database (W, HSS, L)
- EN 1993-1-1 / -1-3 — Eurocode 3: hot-rolled and cold-formed members
- IS 808 — Indian standard rolled sections
- Section modulus · Second moment of area