Frequently Asked Questions

Bangtu has the manufacture ability to offer steel grating of any specifications or types. You only need to inform us your special requirements about dimensions, materials, color and anything you think we should know. 

Specifying steel bar grating involves several key parameters to ensure it meets the requirements of your application. Here are the steps and considerations for specifying steel bar grating:

1. **Material**:

   – **Type of Steel**: Choose between carbon steel, galvanized steel, or stainless steel based on corrosion resistance, strength, and environmental conditions.

   – **Finish**: Specify if the grating should be galvanized, painted, or have a special coating for additional protection.

2. **Grating Type**:

   – **Welded Bar Grating**: Made by welding cross bars to bearing bars at each intersection.

   – **Press-locked Grating**: Cross bars are pressed into bearing bars.

   – **Swage-locked Grating**: Cross bars are swaged into pre-punched holes in the bearing bars.

   – **Riveted Grating**: Bearing bars and cross bars are riveted together.

3. **Bearing Bars**:

   – **Bar Size**: Specify the width and thickness of the bearing bars.

   – **Bar Spacing**: Distance between the centerlines of adjacent bearing bars, typically measured in inches or millimeters (e.g., 1 inch, 1-1/4 inch, etc.).

   – **Orientation**: Direction the bearing bars run, usually along the length of the panel.

4. **Cross Bars**:

   – **Bar Size**: Diameter or size of the cross bars.

   – **Bar Spacing**: Distance between the centerlines of adjacent cross bars (e.g., 4 inches, 6 inches, etc.).

5. **Panel Size**:

   – **Length and Width**: Overall dimensions of the grating panel. Ensure it fits the application space and consider standard sizes for cost efficiency.

6. **Load Requirements**:

   – **Load Type**: Define whether the load is uniform (distributed) or concentrated (point load).

   – **Load Capacity**: Specify the maximum load the grating needs to support, in pounds per square foot (psf) or kilonewtons per square meter (kN/m²).

7. **Deflection Criteria**:

   – Specify the allowable deflection under load, often as a fraction of the span length (e.g., L/240).

8. **Edge Banding and Cutouts**:

   – Determine if the edges of the grating need to be banded for additional strength.

   – Specify any cutouts or custom shapes required to fit around obstructions or meet design requirements.

9. **Surface Treatment**:

   – Choose between plain, serrated, or grooved surfaces based on slip resistance needs.

10. **Compliance and Standards**:

    – Ensure the grating meets relevant standards, such as ASTM, ANSI, or OSHA requirements.

### Example Specification:

– **Material**: Galvanized carbon steel

– **Grating Type**: Welded bar grating

– **Bearing Bars**: 1-1/4″ wide by 1/4″ thick, spaced 1-1/4″ center to center

– **Cross Bars**: 1/4″ diameter, spaced 4″ center to center

– **Panel Size**: 3 feet by 10 feet

– **Load Requirements**: Uniform load of 250 psf

– **Deflection Criteria**: L/240

– **Surface Treatment**: Serrated surface for slip resistance

– **Compliance**: Meets ASTM A123 for galvanizing and OSHA requirements for industrial flooring

This detailed specification ensures that the steel bar grating will meet the functional and safety requirements of the intended application.

The cantilever distance for steel grating, which is the length it can extend beyond its support without additional support, depends on several factors including the type of grating, the load it needs to support, the dimensions and spacing of the bearing bars, and the specific material used. However, there are general guidelines and considerations:

### General Guidelines:

1. **Type of Load**: The nature of the load (uniformly distributed load vs. concentrated load) significantly affects the cantilever capacity.

   – **Uniform Load**: The grating can cantilever a shorter distance under a uniformly distributed load.

   – **Concentrated Load**: The grating can cantilever a longer distance under a point load, but the load application point and magnitude are crucial.

2. **Bearing Bar Size and Spacing**: Larger and more closely spaced bearing bars provide greater strength and allow for longer cantilever distances.

   – **Thicker Bars**: Thicker bearing bars will provide more resistance to bending and allow for longer cantilever spans.

   – **Closer Spacing**: Bars spaced closer together distribute the load more effectively and reduce deflection.

3. **Deflection Criteria**: The allowable deflection under load is typically limited to a fraction of the span length (e.g., L/240 or L/360). The deflection limit will influence the maximum cantilever distance.
4. **Material Properties**: The strength and stiffness of the steel used in the grating will affect its cantilever capacity. Higher strength steels will allow for longer cantilevers.

### Typical Cantilever Distances:

While specific cantilever distances should always be verified against manufacturer guidelines and engineering calculations, typical cantilever distances for steel grating are:

– **Light Loads**: Approximately 4-6 inches (100-150 mm)

– **Moderate Loads**: Approximately 6-12 inches (150-300 mm)

– **Heavy Loads**: Generally, not recommended to cantilever beyond 12 inches (300 mm) without additional support or reinforcement

### Engineering Calculation:

For precise determination, a structural engineer would perform calculations considering:

– **Maximum Allowable Stress**: Ensuring the stress in the bearing bars does not exceed the material’s yield strength.

– **Maximum Allowable Deflection**: Ensuring deflection remains within acceptable limits for safety and functionality.

– **Load Distribution**: Evaluating how the load is distributed across the cantilevered section of the grating.

### Example Calculation:

If using standard welded bar grating with bearing bars spaced 1 inch apart and having a thickness of 1/4 inch, supporting a uniformly distributed load of 250 psf, a typical cantilever might be conservatively estimated around 6-8 inches. However, actual calculations must consider the specific load, grating dimensions, and safety factors.

In conclusion, while a general estimate can provide a rough idea, precise cantilever distances for steel grating should always be determined through detailed engineering analysis and consultation with the grating manufacturer’s specifications.

Steel grating offers a range of benefits that make it a popular choice in various industrial, commercial, and architectural applications. Here are some key advantages:

1. **High Strength-to-Weight Ratio**: Steel grating is strong and can support heavy loads while being relatively lightweight compared to solid metal plates.
2. **Durability**: It is highly durable and can withstand harsh environments, including extreme temperatures, heavy impacts, and abrasive conditions.
3. **Corrosion Resistance**: Galvanized and stainless steel grating options provide excellent resistance to corrosion, making them suitable for use in corrosive environments such as chemical plants, wastewater treatment facilities, and coastal areas.
4. **Slip Resistance**: The open grid design and the option for serrated surfaces enhance slip resistance, providing a safer walking surface in wet or oily conditions.
5. **Ventilation and Drainage**: The open design allows for efficient airflow, light penetration, and drainage, making it ideal for applications requiring ventilation, such as platforms, walkways, and trenches.
6. **Low Maintenance**: Steel grating requires minimal maintenance, reducing the long-term costs associated with upkeep and repairs.
7. **Versatility**: It comes in various types (welded, press-locked, swaged, riveted) and can be customized in terms of bar size, spacing, and surface treatment to meet specific requirements.
8. **Fire Resistance**: Steel is non-combustible, providing an added layer of safety in fire-prone environments.
9. **Ease of Installation**: Steel grating is relatively easy to install, and its modular design allows for quick assembly and disassembly, facilitating maintenance and modifications.
10. **Aesthetic Appeal**: In architectural applications, steel grating can provide a modern, industrial look and can be used in facades, sunshades, and other design elements.
11. **Cost-Effectiveness**: While the initial cost might be higher than some other materials, the long lifespan and low maintenance requirements make it a cost-effective choice over time.
12. **Load Bearing Capacity**: Steel grating is designed to bear heavy loads, making it suitable for use in heavy-duty applications like industrial floors, ramps, and docks.
13. **Eco-Friendly**: Steel is recyclable, and using steel grating can contribute to sustainable building practices by reducing waste and promoting the use of recycled materials.

### Applications:

– **Industrial**: Platforms, walkways, stair treads, trench covers, and drainage grates.

– **Commercial**: Catwalks, mezzanines, fencing, and security screens.

– **Architectural**: Sunshades, facades, grilles, and decorative elements.

– **Public Infrastructure**: Bridge decks, subway grates, and airport runways.

Steel grating’s combination of strength, durability, and versatility makes it a highly advantageous material for a wide range of applications.

The thickness of steel grating depends on the specific application and the load requirements. However, there are some standard thicknesses commonly used in the industry. Here are the typical thicknesses for bearing bars in steel grating:

### Standard Thicknesses:

1. **Light Duty Grating**:

   – **1/8 inch (3.2 mm)**

   – **3/16 inch (4.8 mm)**

2. **Medium Duty Grating**:

   – **1/4 inch (6.4 mm)**

   – **5/16 inch (8.0 mm)**

3. **Heavy Duty Grating**:

   – **3/8 inch (9.5 mm)**

   – **1/2 inch (12.7 mm)**

### Factors Affecting Thickness Selection:

1. **Load Requirements**:

   – **Light Duty**: Suitable for pedestrian traffic or light loads, often used in walkways, platforms, and stair treads.

   – **Medium Duty**: Suitable for moderate loads, often used in industrial floors and mezzanines.

   – **Heavy Duty**: Suitable for heavy loads, often used in truck ramps, docks, and industrial plants.

2. **Span Length**:

   – The distance between supports also influences the required thickness. Longer spans typically require thicker bearing bars to maintain structural integrity and limit deflection.

3. **Material**:

   – The type of steel (e.g., carbon steel, galvanized steel, stainless steel) can influence the selection of thickness due to differences in material properties.

4. **Deflection Criteria**:

   – The acceptable amount of deflection under load can affect the choice of thickness. Stricter deflection limits often require thicker bearing bars.

5. **Surface Treatment**:

   – Additional treatments like serration for slip resistance may also influence the overall thickness.

### Example Specification:

For a standard welded bar grating with a bearing bar thickness of 1/4 inch (6.4 mm), the grating might be specified as follows:

– **Material**: Galvanized carbon steel

– **Bearing Bar Size**: 1-1/4 inch wide by 1/4 inch thick

– **Bearing Bar Spacing**: 1-1/4 inch center to center

– **Cross Bar Size**: 1/4 inch diameter

– **Cross Bar Spacing**: 4 inches center to center

– **Panel Size**: 3 feet by 10 feet

Always consult manufacturer guidelines and perform engineering calculations to determine the appropriate thickness for specific applications, ensuring safety and performance requirements are met.