Technical resource
Steel Grating Load Table for Span and Load Review
Compare support span, bearing bar size, spacing and load condition before confirming the grating panel specification.
Quick reading
Use the load table as a specification filter, not a final design approval
A useful load-table review starts with support span, bearing bar direction and load condition, then moves into bar size, spacing, finish and fabrication details.
Steel grating panels with the same length and width can perform very differently when bearing bar height, thickness, spacing or support span changes. For platforms, trench covers, walkways and stair access, the load table should help narrow the specification before drawings and project requirements are checked.
Selection workflow
How to use a steel grating load table before RFQ
Treat the load table as a sequence of procurement checks. Confirm how the panel is supported first, then match the span and load to a practical bearing bar specification.
Confirm support span
Measure clear span between supports and mark the bearing bar direction.
Define load condition
Separate pedestrian, maintenance, drainage cover and project-specific loads.
Select bearing bar
Match span and load to bar height, thickness and bearing bar spacing.
Check spacing
Review open area, dropped-object control, drainage and cost impact.
Confirm surface and finish
Choose smooth or serrated surface, then match finish to exposure.
Review drawings
Confirm cutouts, banding, frames, fixing clips and packing marks.
Load reference matrix
Steel grating load table for RFQ pre-selection
This matrix helps buyers organize the first specification review before a formal quotation. It is a practical RFQ reference, not a substitute for project engineering approval or local code review.
| Application | Load discussion | Common starting specification | Span review points | Confirm before quotation |
|---|---|---|---|---|
| Pedestrian walkwayPlatforms, catwalks and general access routes. | Walking load, occasional maintenance access and anti-slip surface requirement. | Often reviewed from 25 x 3 mm or 30 x 3 mm bearing bars with 30/40 mm bearing bar spacing. | Confirm clear support span and whether bearing bars run in the correct direction. | Panel size, support layout, smooth or serrated surface, galvanized or painted finish. |
| Industrial platformMaintenance floors, mezzanine access and operating areas. | Higher maintenance load, tool carts, equipment access and longer span sensitivity. | Often reviewed from 30 x 3 mm, 32 x 5 mm, 40 x 3 mm or heavier bars depending on span. | Longer spans usually require deeper or thicker bearing bars and closer specification review. | Live load requirement, support steel, cutouts, kick plate, clips and drawing file. |
| Stair treadsIndustrial stairs, platforms and maintenance access. | Foot traffic, tread width, nosing type, side plates and fixing hole position. | Often reviewed from 25 x 3 mm or 30 x 3 mm bearing bars, with serrated surface when needed. | Span is normally controlled by stair width and side plate support condition. | Tread width, length, nosing, side plate drawing, hole spacing and finish. |
| Trench or drain coverDrainage channels, utility trenches and plant covers. | Pedestrian, trolley, forklift or vehicle condition changes the required grating quickly. | Often reviewed from 30 x 3 mm to 50 x 5 mm or framed heavy-duty options by opening size. | Clear trench opening, seat width and impact load are more important than outside panel size alone. | Traffic type, wheel load or axle load, frame detail, lifting holes and anti-theft options. |
| Heavy-duty or vehicle areaRoad, loading bay and high-load industrial zones. | Requires project-specific load data rather than a standard walkway assumption. | Use heavy-duty steel grating or framed covers after confirming load, span and support details. | Wheel contact area, axle load, dynamic load and support frame must be reviewed together. | Engineering load data, vehicle type, drawing, clear span, frame, fixing and safety factor. |
Important: the table above is for RFQ pre-selection and communication. Final load capacity depends on steel grade, bearing bar dimensions, bar spacing, cross bar spacing, span, support condition, welding, finish and project requirements.
Span selector
Which bearing bar do I need for my span?
Q235 welded grating /30/100, simply supported. A model passes when its design load is at least your load and the deflection under your load is within span/200 and 4 mm (YB/T 4001.1—2019 §8.7.7).
Screening result only. Point loads, carts, vehicles, serrated bars and stainless steel need a separate check — send the drawing and we confirm it in the quotation.
Calculated design values
Steel grating load table: G255–G605 /30/100, Q235 carbon steel
Welded steel grating in Q235 carbon steel: bearing bars 5 mm thick at 30 mm centers (34 bars per meter of width), cross bars at 100 mm centers. Values are calculated with the method of the Chinese steel grating standard YB/T 4001.1—2019, Annex C.
Calculation basis: bending strength design value f = 215 N/mm² (Q235, GB 50017); E = 206,000 N/mm²; stiffness adjustment factor γ = 0.729; simply supported single span.
| Model | Span (mm) → | 600 | 800 | 1000 | 1200 | 1400 | 1600 | 1800 | 2000 |
|---|---|---|---|---|---|---|---|---|---|
| G255/30/100Bearing bar 25 × 5 mmRecommended max. span: 1260 mm | U uniform load, kN/m² | 85 | 48 | 30 | 21 | 16 | |||
| D at U, mm | 4.3 | 7.6 | 11.9 | 17.2 | 23.4 | ||||
| C line load at mid-span, kN/m | 25 | 19 | 15 | 13 | 11 | ||||
| D at C, mm | 3.4 | 6.1 | 9.5 | 13.7 | 18.7 | ||||
| G325/30/100Bearing bar 32 × 5 mmRecommended max. span: 1520 mm | U uniform load, kN/m² | 139 | 78 | 50 | 35 | 25 | 19 | 15 | |
| D at U, mm | 3.4 | 6.0 | 9.3 | 13.4 | 18.3 | 23.9 | 30.2 | ||
| C line load at mid-span, kN/m | 42 | 31 | 25 | 21 | 18 | 16 | 14 | ||
| D at C, mm | 2.7 | 4.8 | 7.5 | 10.7 | 14.6 | 19.1 | 24.2 | ||
| G405/30/100Bearing bar 40 × 5 mmRecommended max. span: 1790 mm | U uniform load, kN/m² | 217 | 122 | 78 | 54 | 40 | 30 | 24 | 19 |
| D at U, mm | 2.7 | 4.8 | 7.5 | 10.7 | 14.6 | 19.1 | 24.2 | 29.8 | |
| C line load at mid-span, kN/m | 65 | 49 | 39 | 32 | 28 | 24 | 22 | 19 | |
| D at C, mm | 2.1 | 3.8 | 6.0 | 8.6 | 11.7 | 15.3 | 19.3 | 23.9 | |
| G505/30/100Bearing bar 50 × 5 mmRecommended max. span: 2120 mm | U uniform load, kN/m² | 338 | 190 | 122 | 85 | 62 | 48 | 38 | 30 |
| D at U, mm | 2.1 | 3.8 | 6.0 | 8.6 | 11.7 | 15.3 | 19.3 | 23.9 | |
| C line load at mid-span, kN/m | 102 | 76 | 61 | 51 | 44 | 38 | 34 | 30 | |
| D at C, mm | 1.7 | 3.1 | 4.8 | 6.9 | 9.4 | 12.2 | 15.5 | 19.1 | |
| G605/30/100Bearing bar 60 × 5 mmRecommended max. span: 2430 mm | U uniform load, kN/m² | 487 | 274 | 175 | 122 | 90 | 69 | 54 | 44 |
| D at U, mm | 1.8 | 3.2 | 5.0 | 7.2 | 9.7 | 12.7 | 16.1 | 19.9 | |
| C line load at mid-span, kN/m | 146 | 110 | 88 | 73 | 63 | 55 | 49 | 44 | |
| D at C, mm | 1.4 | 2.5 | 4.0 | 5.7 | 7.8 | 10.2 | 12.9 | 15.9 |
How to read the table
- U is the design value of a uniform load over the full span; C is the design value of a line load across the panel at mid-span, per meter of panel width; D is the deflection under that design value.
- The recommended maximum span is the span at which a 4 kN/m² uniform load gives 4 mm deflection, as defined in the standard.
- D values are deflections at the full design value. The standard limits deflection under the applied design load to span/200 and 4 mm maximum (§8.7.7), so check deflection for your actual load, not strength alone.
- Lay the grating with the bearing bars running from support to support (bearing bar direction = span direction); cross bars do not carry the load. U and C are imposed loads: the weight of the grating itself is not included.
- Typical design loads in the standard: work platforms 2 kN/m² plus 1.5 kN on 200 × 200 mm; maintenance platforms 4 kN/m²; single-file walkways at least 3.0 kN/m², two-way walkways 5.0 kN/m², crowded walkways 7.5 kN/m² (§8.7).
- These are calculated screening values, not a test certificate. Serrated bars, stainless steel, other bar spacings, cutouts and vehicle loads need a separate check; send your span and load and we will confirm the specification in the quotation, with the load inspection report you require.
US designation 19-W-4
19-W-4 welded steel grating load table (ANSI/NAAMM MBG 531 method)
Bearing bars at 1-3/16 in (30.16 mm) centers and cross bars at 4 in (101.6 mm), in inch-pound units as used in North American specifications. Values are calculated with the ANSI/NAAMM MBG 531 method on the gross section of the bearing bars; the method was checked against published 19-W-4 tables.
Calculation basis: allowable bending stress 18,000 psi (124 MPa); E = 29,000,000 psi (200,000 MPa); carbon steel bearing bars (ASTM A1011 CS Type B in the NAAMM basis); simply supported single span.
| Bearing bar (in / mm) | Span (ft-in) → | 2′-0″ | 2′-6″ | 3′-0″ | 3′-6″ | 4′-0″ | 4′-6″ | 5′-0″ | 5′-6″ | 6′-0″ | 6′-6″ | 7′-0″ | 8′-0″ | 9′-0″ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3/4 × 1/8 in19 × 3.2 mmMax. pedestrian span: 3'-5" (1050 mm) | U uniform load, psf | 355 | 227 | 158 | 116 | |||||||||
| D at U, in | 0.099 | 0.155 | 0.223 | 0.304 | ||||||||||
| C mid-span load, lb/ft of width | 355 | 284 | 237 | 203 | ||||||||||
| D at C, in | 0.079 | 0.124 | 0.179 | 0.243 | ||||||||||
| 1 × 1/8 in25 × 3.2 mmMax. pedestrian span: 4'-3" (1310 mm) | U uniform load, psf | 632 | 404 | 281 | 206 | 158 | 125 | 101 | ||||||
| D at U, in | 0.074 | 0.116 | 0.168 | 0.228 | 0.298 | 0.377 | 0.466 | |||||||
| C mid-span load, lb/ft of width | 632 | 505 | 421 | 361 | 316 | 281 | 253 | |||||||
| D at C, in | 0.060 | 0.093 | 0.134 | 0.182 | 0.238 | 0.302 | 0.372 | |||||||
| 1 × 3/16 in25 × 4.8 mmMax. pedestrian span: 4'-9" (1450 mm) | U uniform load, psf | 947 | 606 | 421 | 309 | 237 | 187 | 152 | 125 | 105 | ||||
| D at U, in | 0.074 | 0.116 | 0.168 | 0.228 | 0.298 | 0.377 | 0.466 | 0.563 | 0.670 | |||||
| C mid-span load, lb/ft of width | 947 | 758 | 632 | 541 | 474 | 421 | 379 | 344 | 316 | |||||
| D at C, in | 0.060 | 0.093 | 0.134 | 0.182 | 0.238 | 0.302 | 0.372 | 0.451 | 0.536 | |||||
| 1-1/4 × 3/16 in32 × 4.8 mmMax. pedestrian span: 5'-7" (1710 mm) | U uniform load, psf | 1,480 | 947 | 658 | 483 | 370 | 292 | 237 | 196 | 164 | 140 | 121 | ||
| D at U, in | 0.060 | 0.093 | 0.134 | 0.182 | 0.238 | 0.302 | 0.372 | 0.451 | 0.536 | 0.629 | 0.730 | |||
| C mid-span load, lb/ft of width | 1,480 | 1,184 | 987 | 846 | 740 | 658 | 592 | 538 | 493 | 455 | 423 | |||
| D at C, in | 0.048 | 0.074 | 0.107 | 0.146 | 0.191 | 0.241 | 0.298 | 0.360 | 0.429 | 0.504 | 0.584 | |||
| 1-1/2 × 3/16 in38 × 4.8 mmMax. pedestrian span: 6'-5" (1960 mm) | U uniform load, psf | 2,132 | 1,364 | 947 | 696 | 533 | 421 | 341 | 282 | 237 | 202 | 174 | 133 | 105 |
| D at U, in | 0.050 | 0.078 | 0.112 | 0.152 | 0.199 | 0.251 | 0.310 | 0.376 | 0.447 | 0.524 | 0.608 | 0.794 | 1.006 | |
| C mid-span load, lb/ft of width | 2,132 | 1,705 | 1,421 | 1,218 | 1,066 | 947 | 853 | 775 | 711 | 656 | 609 | 533 | 474 | |
| D at C, in | 0.040 | 0.062 | 0.089 | 0.122 | 0.159 | 0.201 | 0.248 | 0.300 | 0.358 | 0.420 | 0.487 | 0.636 | 0.804 | |
| 2 × 3/16 in51 × 4.8 mmMax. pedestrian span: 7'-11" (2430 mm) | U uniform load, psf | 3,789 | 2,425 | 1,684 | 1,237 | 947 | 749 | 606 | 501 | 421 | 359 | 309 | 237 | 187 |
| D at U, in | 0.037 | 0.058 | 0.084 | 0.114 | 0.149 | 0.189 | 0.233 | 0.282 | 0.335 | 0.393 | 0.456 | 0.596 | 0.754 | |
| C mid-span load, lb/ft of width | 3,789 | 3,032 | 2,526 | 2,165 | 1,895 | 1,684 | 1,516 | 1,378 | 1,263 | 1,166 | 1,083 | 947 | 842 | |
| D at C, in | 0.030 | 0.047 | 0.067 | 0.091 | 0.119 | 0.151 | 0.186 | 0.225 | 0.268 | 0.315 | 0.365 | 0.477 | 0.603 |
How to read the table
- U is the design value of a uniform load over the full span; C is the design value of a line load across the panel at mid-span, per meter of panel width; D is the deflection under that design value.
- Maximum pedestrian span: the longest span at which a 100 psf (4.8 kPa) uniform load gives 1/4 in (6.4 mm) deflection.
- Lay the grating with the bearing bars running from support to support (bearing bar direction = span direction); cross bars do not carry the load. U and C are imposed loads: the weight of the grating itself is not included.
- Loads do not include the weight of the grating. For serrated bars, use a bearing bar 1/4 in (6 mm) deeper for the same values. Spans where U is below 100 psf are left blank.
- Conversions: 1 psf = 0.0479 kPa; 1 lb/ft = 14.6 N/m; 1 in = 25.4 mm. These are calculated screening values, not a test certificate; we confirm the specification for your span and load in the quotation.
Specification checklist
Details that change load-table selection
- ApplicationPlatform, walkway, trench cover, drain cover, stair tread or equipment access.
- Load directionBearing bars should span between supports, not across unsupported edges.
- Panel layoutOverall dimensions, cutouts, banding, installation gaps and support locations.
- SurfaceSmooth for general use or serrated for wet, oily and outdoor walking areas.
- FinishMill finish, painted, powder coated, hot-dip galvanized or stainless finish.
Buyer risk notes
Common mistakes to avoid
- Using the product name alone to confirm load capacity.
- Sending panel length and width without bearing bar direction.
- Confusing cross bar spacing with bearing bar spacing.
- Ignoring corrosion protection on outdoor or wet projects.
- Leaving cutouts, frames and fixing clips until after quotation.
RFQ preparation
Send these details for faster load and span review
Drawings are preferred, but a clear sketch or site photo with dimensions is also useful. The goal is to show how the grating is supported, loaded, finished and packed.
| Drawing | PDF, DWG, DXF, sketch or photo showing support layout and panel direction. |
|---|---|
| Span | Clear support span and bearing bar direction. |
| Load | Pedestrian, maintenance, drainage cover, equipment access or project load data. |
| Specification | Bearing bar size, bar spacing, cross bar spacing, material and finish if known. |
| Order details | Quantity, destination, packing marks and required delivery timing. |
FAQ
What is a steel grating load table?
A steel grating load table is a reference used to compare span, bearing bar size, bar spacing and expected load performance before selecting or quoting grating panels.
What details affect steel grating load capacity?
Bearing bar height, bearing bar thickness, support span, bearing bar direction, cross bar spacing, material grade, panel layout and installation support all affect load performance.
Is bearing bar direction important?
Yes. The bearing bars must span between supports. If the bearing bar direction is wrong, the panel may not perform as expected even if the product name looks correct.
Do load tables replace project engineering review?
No. Load tables help with early specification comparison, but final selection should be checked against actual support span, load case, drawings and project requirements.
Can QY Metal Tech help check span and load requirements?
Yes. Buyers can send drawings, support span, load requirement and application notes so QY Metal Tech can review the specification before quotation.
Table boundary
This Load Table Is for Steel Bar Grating
Do not use a steel bearing-bar load value for molded or pultruded FRP grating. FRP requires the product-specific series, panel depth, mesh or bar spacing, bearing direction, clear span, load type, deflection limit, units and table revision.
For fiberglass grating questions, use the FRP grating load and span table guide and the FRP selection guide. Final structural suitability and local compliance require project approval.
Keep the table sources separate
Downloadable reference versus calculated screening tables
The linked Chinese PDF is labeled YB/T 4001.1-2007, tables E1-E7, printed pages 26-32. It is not a PDF export of the calculated metric and imperial screening tables displayed on this page. Read each table’s stated edition, geometry, load case and deflection basis independently.
| Downloaded-reference field | Meaning and unit |
|---|---|
| U | Imposed uniformly distributed load in kN/m², not panel weight or a concentrated wheel load. |
| C | Imposed line load in kN/m at the span center, perpendicular to the bearing bars; not an isolated point load. |
| D | Deflection in mm under the corresponding U or C load and span column. |
| Populated source region | The PDF’s own note uses a 2 kN/m² uniform load and less than 4 mm deflection. This must not be substituted for the separate website screening criteria. |
| Geometry and width | E1-E3: flat bars at 30/40/20 mm centers; E4-E5: I-section bars at 30/40 mm centers; E6: heavy-duty models; E7: bearing-bar count versus nominal panel width. |
The E7 dimensional records are also readable on the steel bar grating product page. Nominal width runs across the bearing bars and is not the clear support span. A field requiring drawing confirmation is explicitly marked instead of being silently corrected.
For an RFQ, identify which table and edition you are using. Include material, exact model and spacing, span direction, support and bearing details, load type and area, deflection criterion, cutouts and drawing revision. Empty source cells do not mean zero load or an approved span. No new capacity rating is established by this explanation.
Load table to RFQ
Turn load table checks into a drawing-based quotation
After checking the load table, send span, bar size and panel details for a drawing-based quotation.
- Load basisClear span, bearing bar direction, load class and deflection limit if specified.
- Panel detailsPanel size, grating type, bar size, spacing, cutouts and fixing method.
- Project notesQuantity, finish, packing, destination and any drawing or standard requirement.
RFQ support
Need help checking steel grating load and span?
Send drawings, span, load requirement, material, finish, quantity and destination. QY Metal Tech will review the specification and reply with quotation support.
