How are castellated and cellular steel beams fabricated?

Castellated and cellular beams are fabricated from standard rolled W-shapes through a flame-cutting and re-welding process that increases the beam depth by approximately 50% without adding steel weight. The process: (1) A standard W-shape is flame-cut along the web in a specific pattern — a zigzag (trapezoidal) pattern for castellated beams producing hexagonal openings, or a sinusoidal pattern for cellular beams producing circular openings. The cutting is performed using CNC plasma or oxy-fuel cutting machines with programmed cut paths. (2) The two cut halves are separated, shifted longitudinally by one half-opening pitch, and re-welded with the web peaks aligned. The re-welding is typically a single-bevel CJP groove weld or a fillet weld along the full length of the reconnected web. (3) For a castellated beam, the result is a beam approximately 1.5 times the parent depth (dt ≈ 1.5 * d_original) with regular hexagonal web openings. For example, a parent W18x35 (d = 17.7 in) becomes a CB27x35 (d = approximately 27 in, same weight = 35 plf). For a cellular beam, circular openings of diameter Do = 0.6 to 0.8 times the finished beam depth are created, with spacing S = Do + e where e is the web post width. (4) The moment of inertia approximately doubles because I is proportional to depth cubed for the flange contribution — I_cellular ≈ 2.0 * I_parent. This means the beam achieves approximately double the flexural stiffness with zero weight gain — a dramatic efficiency improvement for long-span applications. The weight savings compared to a rolled section of equivalent depth: a CB27x35 at 35 plf replaces a W27x84 at 84 plf for the same depth, saving 58% of steel weight. More typically, for spans of 30-50 ft, castellated beams save 25-35% of steel weight compared to rolled sections of equivalent performance. The trade-off is fabrication cost: cutting and re-welding adds approximately $0.15-0.25/lb to the beam cost, partially offsetting the material savings. The economic crossover is typically at spans above 35-40 ft, where the material savings from the lighter section outweigh the fabrication premium. Below 30 ft, rolled sections are usually more economical because the fabrication premium exceeds the modest material savings.

What is Vierendeel bending in castellated beams and how is it checked?

Vierendeel bending is the local bending that develops in the tee sections above and below each web opening in a castellated or cellular beam. At the location of an opening, the beam acts like a Vierendeel truss — the tee sections (top and bottom) resist the global moment through axial tension and compression (flange action), and resist the global shear through local double-curvature bending of the tee stems. The Vierendeel mechanism is the most critical limit state for castellated beams and often governs the opening size and spacing. The Vierendeel bending moment in each tee is approximately: M_v = V_global * S / 4, where V_global is the total shear at the opening location and S is the center-to-center spacing of the openings. More precisely, per AISC Design Guide 31, the Vierendeel moment is distributed between the top and bottom tees in proportion to their section properties: M_vt_top = V_global * e * (I_t_top / (I_t_top + I_t_bot)), where e is the distance from the center of the opening to the tee centroid. The tee section must be checked for the combined stresses: axial force (from global moment, P = M * A_tee / I_net) plus Vierendeel bending moment (M_v). The interaction check typically uses AISC 360 Chapter H: P_r/P_c + M_r/M_c <= 1.0, with the tee section classified as compact or non-compact based on the stem width-to-thickness ratio. Critical parameters controlling Vierendeel capacity: (1) Tee stem depth — deeper tees above and below the opening provide greater Vierendeel moment capacity. A minimum tee depth of 0.15 * d_g (finished beam depth) is recommended. (2) Opening width-to-depth ratio — wider openings increase the Vierendeel moment arm (S), so opening length should be controlled. For castellated beams, the opening length-to-height ratio typically ranges from 1.0 to 1.5. For cellular beams, the opening is circular and the effective Vierendeel length is less than the diameter. (3) Web post width e — wider web posts between openings reduce the Vierendeel moment by providing stiffer support, at the cost of more steel and less openness for services. A typical e/Do ratio is 0.25 to 0.50. The Vierendeel check is performed at each opening along the beam. Openings near supports (high shear, low moment) are typically critical for Vierendeel bending; openings near mid-span (low shear, high moment) are typically critical for axial force.

What is web post buckling and how does it limit castellated beam design?

Web post buckling is the instability of the solid web region (the 'post') between adjacent openings in a castellated or cellular beam. The web post acts like a short column or shear panel, transferring the Vierendeel shear between openings. When the post is too slender (too narrow or too tall relative to its thickness), it buckles laterally or in shear, causing a sudden loss of capacity. The web post width e is the most critical geometric parameter for this limit state. AISC Design Guide 31 provides the web post buckling check: the horizontal shear force in the web post V_h must be less than the buckling capacity. For castellated beams: V_h = ho/3 for hexagonal (castellated) openings, and e >= Do/4 for circular (cellular) openings. Below these minimums, web post buckling is likely to govern. The web post also resists the Vierendeel moment transfer: the horizontal shear flows from one tee, through the web post, to the adjacent tee. This creates a double-curvature bending pattern in the post. For cellular beams (circular openings), the web post has a more favorable geometry because the curved opening creates a wider post at the mid-height where the shear is highest. For castellated beams (hexagonal openings), the post has parallel sides, concentrating the shear over a constant width — this makes castellated beams slightly more susceptible to web post buckling than cellular beams of equivalent geometry. Practical design rules to avoid web post buckling: (1) Keep e/ho >= 1/3 for castellated beams. (2) Keep e/Do >= 1/4 for cellular beams. (3) For deep beams (d > 36 in), increase e by 20-30% beyond the minimum to account for the higher slenderness. (4) If multiple openings are closely spaced (S/Do < 1.5), check web post buckling for the combined shear from both Vierendeel panels. (5) For beams with high shear demand (short spans, heavy loads), increase the web post width or consider a parent section with a thicker web.

When should I use a castellated beam instead of a rolled W-shape?

Castellated and cellular beams are economically justified when the span, loading, and service integration benefits outweigh the fabrication cost premium. The decision criteria: (1) Span length — castellated beams become cost-competitive at spans of 35-40 ft and are strongly preferred above 50 ft. At 30 ft, a rolled W21x44 (44 plf, I_x = 843 in^4) is almost always cheaper than a CB27x35 (35 plf, I_x ≈ 1,600 in^4) because the fabrication premium of $0.15-0.25/lb exceeds the 9 plf weight savings over a 30 ft length (270 lb savings = approximately $0.27/lb at $1.00/lb installed). At 50 ft, the same comparison yields 450 lb savings, and the material savings now outweigh the fabrication premium. (2) Service integration — the primary non-structural advantage is that the web openings provide built-in pathways for MEP services. In a typical office building, running ducts through beam openings can save 6-12 inches of floor-to-floor height compared to running ducts below the beams. Over a 10-story building, this can save an entire story of building height, which is worth far more than the beam cost difference. (3) Vibration performance — castellated beams are deeper (higher I_x) but lighter (lower mass) than equivalent rolled sections. Higher I_x increases the fundamental frequency (f ∝ sqrt(I/m)), which is favorable, but lower mass per foot reduces damping. For vibration-sensitive floors (offices, hospitals), check the DG11 vibration criteria explicitly — the deeper beam may perform better or worse than a rolled section depending on the mass-stiffness balance. (4) Ceiling and lighting integration — the openings allow recessed lighting and sprinkler pipes to pass through, creating a cleaner ceiling appearance. (5) Architectural expression — exposed castellated beams are a distinctive architectural feature in high-end commercial and institutional buildings. The hexagonal or circular openings create a rhythm that architects exploit for aesthetic effect. When to NOT use castellated beams: (a) Short spans under 30 ft — rolled sections are cheaper. (b) Highly loaded members where the Vierendeel or web post buckling limit states require thick webs or narrow openings that negate the weight savings. (c) Fatigue-sensitive applications — the re-entrant corners at hexagonal openings are stress concentrations that reduce fatigue life. Cellular beams (circular openings) are preferred for fatigue applications because the smooth opening profile has lower Kt. (d) Seismic moment frames — castellated beams are not prequalified for SMF or IMF connections per AISC 358.

What are the deflection characteristics of castellated beams compared to parent sections?

The deflection behavior of castellated beams is more complex than rolled sections because the web openings introduce additional shear deformation that reduces the effective stiffness. For a solid-web beam, deflection is dominated by flexural deformation (delta_flex ∝ L^3/EI), and shear deformation contributes only about 1-3% of the total. For a castellated beam, the web openings increase the shear deformation contribution to 10-20% of the total because the Vierendeel action at each opening creates local bending that adds to the global displacement. The effective moment of inertia I_eff is approximately 0.85 to 0.95 times the gross transformed I of the full-depth section, depending on the opening ratio. For a castellated beam with ho/dt = 0.55 (opening height = 55% of beam depth): I_eff ≈ 0.90 * I_gross. For ho/dt = 0.70 (aggressive openings): I_eff ≈ 0.85 * I_gross. For ho/dt = 0.40 (conservative openings): I_eff ≈ 0.95 * I_gross. AISC DG31 provides a detailed method for calculating the additional shear deflection: delta_total = delta_flex + delta_shear, where delta_shear = sum(V_i * e_o / (12 * E * I_tee_i) * ...) summing the Vierendeel contributions over each opening. In practice: for a CB27x35 at 40 ft span with typical floor loads, delta_flex ≈ 0.55 inches and delta_shear ≈ 0.07 inches, for a total of 0.62 inches. The rolled equivalent (W27x84) might have delta = 0.44 inches (no shear contribution beyond the typical 2%). The castellated beam deflects about 40% more than a rolled beam of the same depth because it is 58% lighter (lower I despite similar depth). This is a key design consideration: castellated beams trade deflection performance for weight savings. Camber specifications: castellated beams are cambered during fabrication by cutting the two halves with an offset profile that pre-cambers the finished beam. Typical camber = 75% of dead load deflection, same as rolled beams per AISC 303. Because the beam depth is larger, the camber tolerance (L/300 for camber deviation) is more generous in absolute terms. For long-span roof applications where ponding is a concern, the additional shear deflection must be explicitly included in the ponding check (ASCE 7 requires the roof slope to be adequate after total load deflection).

Castellated & Cellular Beam Design — Geometry, Limit States & Sizing

Castellated beams are fabricated by cutting a rolled W-shape along a zigzag pattern, then re-welding the two halves offset to create a deeper section with hexagonal web openings. Cellular beams use a similar process but produce circular openings. Both types increase the beam depth by roughly 50% without adding steel weight, dramatically improving flexural stiffness for long-span floor and roof applications.

How castellated beams are made

A standard W-shape is flame-cut along the web in a zigzag (castellated) or sinusoidal (cellular) pattern. The two halves are separated and re-welded with the peaks aligned, producing a beam approximately 1.5d deep (where d is the original section depth). For example, a W18x35 becomes a CB27x35 -- same weight, 50% deeper, with significantly higher moment of inertia.

The key geometric parameters per AISC Design Guide 31:

Parameter	Castellated (hexagonal)	Cellular (circular)
Opening height	typically 0.5 _ dt to 0.75 _ dt	diameter Do = 0.6 _ dt to 0.8 _ dt
Web post width (e)	>= ho/3 for strength	>= Do/4
Spacing (S)	e + opening width	center-to-center = Do + e
Overall depth (dt)	~1.5 * d_original	~1.5 * d_original

Common castellated beam profiles

Parent Section	Castellated Depth (in)	Opening Height (in)	Weight (plf)	Ix Increase
W16x26	24	12	26	~2.0x
W18x35	27	14	35	~2.0x
W21x44	32	16	44	~2.0x
W24x55	36	18	55	~2.0x

The moment of inertia approximately doubles because I is proportional to depth cubed for the flanges.

Castellated beam weight efficiency

System	Span (ft)	Weight (plf)	Reason
W18x50 rolled	30	50	Solid web
CB27x35 castellated	30	35	30% lighter, same I
W21x44 rolled	40	44	Solid web
CB32x44 castellated	40	44	Same weight, more I
W24x55 rolled	45	55	Solid web
CB36x40 castellated	45	40	27% lighter

For spans 30-50 ft, castellated beams typically save 25-35% of steel weight compared to rolled sections.

Limit states unique to castellated beams

Standard beam checks (flexure, shear, deflection) still apply, but castellated beams introduce additional failure modes:

1. Vierendeel bending -- At each opening, the beam acts like a Vierendeel truss. The tee sections above and below the opening resist the shear force through local bending. The Vierendeel moment in each tee is approximately:

Mv = Vglobal * S / 4

Where Vglobal is the global shear at the opening and S is the opening spacing. Each tee must resist Mv with its own plastic moment capacity (Mp,tee = Fy * Zx,tee). This check typically governs near supports where shear is highest.

2. Web post buckling -- The narrow web post between adjacent openings can buckle horizontally under the horizontal shear transferred between tee sections. Web post buckling is checked using the method in AISC Design Guide 31 Section 5.3, which treats the post as an effective strut.

3. Web post flexure (horizontal bending) -- The web post bends about its vertical axis due to the difference in axial forces between adjacent tee sections. The interaction of this bending with the vertical shear determines whether the post is adequate.

4. Lateral-torsional buckling of tee sections -- The compression tee at an opening is laterally unbraced across the opening width. For large openings with high compression, the tee can buckle laterally.

5. Compression flange yielding -- At points of high moment, the reduced cross-section through the opening must still resist the global bending moment.

Complete design checklist

For every castellated or cellular beam, check ALL of the following:

Global flexure at critical sections (through openings and through solid web posts)
Global shear at supports
Vierendeel bending at each opening (top and bottom tees)
Web post buckling between adjacent openings
Web post flexural capacity
Lateral-torsional buckling of compression tee
Deflection (consider reduced stiffness at openings)
Floor vibration (special consideration for long-span cellular beams)
Connection capacity at ends (reduced web area)
Composite action (if applicable)

Worked example -- Vierendeel check at opening

Given: CB27x35 (from W18x35), Fy = 50 ksi. Opening height ho = 14 in, spacing S = 18 in, web post e = 4 in. Global shear at the opening Vu = 30 kips.

Step 1: Vierendeel moment: Mv = 30 * 18 / 4 = 135 kip-in per tee.

Step 2: Tee section properties: Top tee: flange = 6.00 _ 0.425 in, stem depth = (27 - 14)/2 = 6.5 in, tw = 0.300 in. Approximate Zx,tee = 0.425 _ 6.00 _ (6.5 - 0.425/2) + 0.300 _ 6.075^2 / 4 = 16.0 + 2.77 = 18.8 in^3.

Step 3: phiMp,tee = 0.90 _ 50 _ 18.8 / 2 = 423 kip-in >> 135 kip-in OK.

Worked example -- web post buckling

Given: Same CB27x35, web post width e = 4 in, web thickness tw = 0.300 in, post height = ho = 14 in.

Step 1: Web post slenderness: kl/r = 0.5 _ 14 / (sqrt(12) _ 4/(2*0.300)) -- treating the post as a fixed-fixed column of height ho and cross-section e x tw.

Step 2: Post area: Ap = 2 _ e _ tw = 2 _ 4 _ 0.300 = 2.40 in^2 (post includes web on both sides of the opening).

Step 3: Horizontal shear through post: Vh = change in tee axial force between adjacent openings. For uniform load: Vh = w _ S / 2 = 2.5 _ 18 / 2 = 22.5 kips per post.

Step 4: phiVh = 0.90 _ 2.40 _ 0.6 * 50 = 64.8 kips > 22.5 kips OK.

For closely spaced openings (e < ho/3), web post buckling often governs and may require infill plates.

Span-to-depth ratios

Castellated beams excel at long spans. Typical span-to-depth ratios:

Application	Span/depth (composite)	Span/depth (non-composite)
Office floors	20-24	16-20
Parking garages	18-22	14-18
Roof beams	22-28	18-24
Industrial	18-22	14-18

A cellular beam spanning 45 ft with dt = 27 in gives span/depth = 20 -- efficient for a composite office floor.

Maximum economic span by section type

Beam Type	Economic Span Range (ft)	Weight Efficiency
Rolled W-shape	15-35	Baseline
Castellated beam	25-50	25-35% lighter
Cellular beam	25-55	25-40% lighter
Plate girder	40-120	Custom
Steel truss	60-150	Lightest

Castellated beams fill the gap between rolled shapes and plate girders for medium to long spans.

When to infill openings

Not all openings can remain open. Infill plates are welded to fill openings when:

Near supports where shear is high (typically first 1-2 openings from each end)
At concentrated load points where local effects are severe
When web post buckling governs and increasing post width is not practical
At connections where the reduced section cannot develop the required capacity

Infill plate design

Opening Type	Infill Plate	Weld
Hexagonal	Cut from same web	Fillet weld, both sides
Circular	Circular plug	Full-penetration or fillet
Rectangular	Flat plate	Fillet weld, all sides

The infill restores the full section properties at the opening location.

Floor vibration considerations

Castellated and cellular beams have reduced mass compared to solid-web beams, which can affect floor vibration performance. AISC Design Guide 11 and AISC DG31 provide guidance:

Minimum natural frequency: 3 Hz for offices, 5 Hz for rhythmic activities
Castellated beams have 15-20% lower mass than equivalent rolled sections
The reduced mass partially offsets the reduced stiffness, so vibration performance is often similar
For sensitive occupancies (operating rooms, laboratories), check floor acceleration per DG11

Multi-code comparison

AISC Design Guide 31 (USA): The primary US reference for castellated and cellular beam design. Provides detailed procedures for Vierendeel bending, web post buckling, and horizontal shear. Uses LRFD with phi = 0.90 for flexure and phi = 0.90 for the web post checks.

SCI P355 (UK/Europe): The Steel Construction Institute publication P355 covers design of composite beams with large web openings per EN 1993. Uses the Vierendeel mechanism approach with Eurocode partial safety factors (gamma_M0 = 1.00, gamma_M1 = 1.00).

AS 4100-2020 (Australia): No specific castellated beam provisions exist in AS 4100. Australian practice follows SCI P355 or first-principles Vierendeel analysis using AS 4100 capacity reduction factors (phi = 0.90 for flexure, phi = 0.90 for shear).

Cross-code Vierendeel capacity comparison

Code	phiMp,tee Basis	Safety Factor	Result
AISC DG31	phi _ Fy _ Zx,tee	phi = 0.90	~423 kip-in
EN 1993/SCI	fy * Wel,tee/gamma	gamma = 1.00	~410 kip-in
AS 4100	phi _ fy _ Zx,tee	phi = 0.90	~423 kip-in

All codes produce similar results for the Vierendeel check.

Common mistakes

Placing openings in high-shear zones near supports. Vierendeel bending is proportional to global shear. Openings in the end quarter of the span, where shear is highest, frequently fail the Vierendeel check. Infill the first one or two openings near each support.
Ignoring web post buckling for closely-spaced openings. Reducing the web post width (e) to fit more openings increases the risk of web post buckling. Minimum e >= ho/3 (castellated) or Do/4 (cellular) is a practical floor.
Using non-composite section properties for deflection when the slab is composite. Castellated and cellular beams are almost always designed as composite with the concrete slab. Using non-composite stiffness overestimates deflection by 40-60%.
Forgetting to check the net section at openings for axial load. When castellated beams carry axial force from diaphragm action, the reduced net section at each opening must be checked for combined axial and bending demand.
Not accounting for floor vibration. The lighter weight of castellated beams can lead to objectionable floor vibrations. Check per AISC Design Guide 11.
Specifying castellated beams for short spans. Below about 25 ft, the fabrication cost of cutting and re-welding exceeds the material savings from using a lighter section. Stick with rolled shapes for short spans.

Frequently asked questions

What is the difference between castellated and cellular beams? Castellated beams have hexagonal openings; cellular beams have circular openings. Both are made by cutting and re-welding a standard W-shape. Cellular beams are more common in modern practice because circular openings are easier to analyze and provide better stress distribution.

How much weight do castellated beams save? Typically 25-35% compared to a rolled W-shape of equivalent stiffness. The savings increase with span length.

What is the maximum opening size? Hexagonal openings: up to 0.75 _ dt. Circular openings: up to 0.8 _ dt. Larger openings require special analysis and often need reinforcement.

Do castellated beams cost more than rolled sections? Yes, fabrication cost is higher due to cutting and re-welding. However, the material savings and reduced foundation loads often make the total project cost lower, especially for spans over 30 ft.

Can I use castellated beams for moment frames? Generally not recommended. The web openings reduce the beam's ability to develop full plastic hinging at connections. Special analysis is required if castellated beams are used in moment-resisting frames.

How do I handle connections at castellated beam ends? The end connection must be designed for the reduced web area. Options include: infilling the end openings, using thicker end plates, or providing a short solid-web transition section at each end.

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Castellated Beam Types

Castellated beams are produced by cutting a standard wide-flange section longitudinally along a predetermined pattern, offsetting the two halves, and welding them back together. The resulting beam has a deeper cross-section with regularly spaced openings (castellations) in the web. The cutting pattern determines the opening geometry.

Type	Opening Shape	Depth Increase	Max Opening Depth	Key Advantage	Common Application
Hexagonal (standard)	Regular hexagon	1.5× parent depth	~0.6× finished depth	Highest moment capacity gain	Office buildings, parking structures
Octagonal	Elongated octagon	1.3–1.5× parent depth	~0.55× finished depth	Smoother stress distribution	Industrial mezzanines, long-span floors
Sinusoidal (Angelina)	Sinusoidal wave	1.3–1.5× parent depth	~0.5× finished depth	Lowest stress concentration	Architectural applications, exposed steel
Diamond (custom)	Diamond/rhombus	1.3–1.4× parent depth	~0.45× finished depth	Aesthetic appeal	Feature structures, canopies
Circular (cellular)	Circular holes	1.3–1.6× parent depth	~0.65× finished depth	Best for services penetration	Modern multi-service buildings

Castellated Beam Design Considerations

Designing castellated beams requires checks beyond those for standard I-sections. The web openings introduce additional limit states that must be evaluated individually. Per AISC 360-22 and design guides, the following must be checked.

Vierendeel bending occurs at the web openings when shear force causes secondary bending in the top and bottom tees above and below the opening. The tees act as short beams spanning between solid web posts. This is often the governing limit state for heavily loaded beams with large openings.

Web post buckling occurs at the narrow solid section between adjacent openings. The web post is subjected to combined shear and bending and can buckle laterally if the post width is insufficient relative to its depth. This limit state is particularly critical for closely spaced hexagonal openings.

Horizontal shear in web post — The web post transfers horizontal shear between the top and bottom tees. The post must have sufficient cross-sectional area to resist this shear without yielding.

Lateral-torsional buckling — Castellated beams are more susceptible to LTB than their parent sections because the deeper cross-section has different lateral stiffness characteristics. The effective length for LTB should account for the reduced torsional rigidity at openings.

Web Post Buckling Check

The web post between openings is the most critical design element. The following simplified procedure is based on the AISC Design Guide 31 approach for cellular and castellated beams.

Web post buckling check (simplified):
1. Determine web post width: wp = s - d_o (opening pitch minus opening depth)
2. Calculate web post shear: V_post = V_u × (d_o / s)
3. Check post slenderness: λ = wp / (tw × √(k_s))
4. If λ ≤ λ_p: φVn = φ × 0.6 × Fy × tw × wp  (yielding governs)
5. If λ > λ_p: φVn = φ × 0.6 × Fy × tw × wp × (λ_p / λ)²  (buckling governs)
where:
  d_o = opening depth
  s = opening pitch (center-to-center)
  k_s = shear buckling coefficient (typically 5.34 for rectangular posts)
  λ_p = limiting slenderness for compact posts

Vierendeel Bending Check

Vierendeel bending is the secondary bending that develops in the top and bottom tees at each opening due to the global shear force. The check involves treating each tee as a fixed-end beam spanning the opening length.

Vierendeel moment at opening:
  M_v = V_u × e_o / 4  (for point load at mid-opening)

where:
  V_u = factored shear at opening centerline
  e_o = opening length (clear horizontal dimension)

Check each tee:
  M_u,tee = M_v ≤ φ × M_n,tee = φ × Fy × S_tee

If V_u is high and e_o is large, stiffener plates may be required
at the opening corners to reduce vierendeel bending stresses.

Typical Castellated Beam Span Ranges

The table below provides practical span ranges for castellated beams by finished depth, assuming typical office floor loads (50 psf live + 20 psf superimposed dead).

Parent Section	Finished Depth (in)	Typical Span Range (ft)	Max Opening Depth (in)	Opening Pitch (in)	Weight (plf)
W12x26 → castellated	18	25–35	10	24	26
W14x30 → castellated	21	30–40	12	28	30
W16x36 → castellated	24	35–50	14	32	36
W18x46 → castellated	27	40–55	16	36	46
W21x57 → castellated	32	45–65	19	42	57
W24x68 → castellated	36	50–70	21	48	68
W27x84 → castellated	40	55–80	24	52	84
W30x99 → castellated	45	60–90	27	58	99
W33x118 → castellated	50	70–100	30	64	118
W36x135 → castellated	54	75–110	32	70	135

Note: Actual span capacity depends on loading, bracing conditions, opening geometry, and serviceability requirements (L/360 for floors, L/240 for roofs).

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This page is for educational and reference use only. It does not constitute professional engineering advice. All design values must be verified against the applicable standard and project specification before use. The site operator disclaims liability for any loss arising from the use of this information.

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