Our carbon steel plate flange is made according to the ASTM A105 standard, and the chemical composition ratio takes into account both strength and processability: the carbon content is 0.3-0.35%, manganese is 0.6-1.05%, and there is a little silicon. As a result, its tensile strength can reach 480-650 MPa, and the elongation is 23%. It is suitable for medium and low pressure systems such as water pipelines, HVAC and general industrial occasions.
Wholesale people think it is cost-effective - 35% cheaper than stainless steel flanges, but it can handle most non-corrosive scenes. We have done bending tests according to the ASTM E290 standard, and it did not crack even when bent to 180 degrees. Even if customers install it in a narrow space, they don't have to worry about it breaking.
We offer two key finishes: oiled (to prevent rust during storage) and sandblasted (Sa 2.5 per ISO 8501-1) for better paint adhesion in outdoor settings. The sandblasted surface has a roughness of 50-80μm, which helps paint stick 50% longer than untreated surfaces.
Our CNC machining ensures precise dimensions: flange thickness tolerance is ±0.5mm, and the bolt circle diameter stays within ±0.3mm (ASME B16.5). We also provide custom drilling for non-standard bolt patterns, with a turnaround time of 48 hours for small batches, and every flange gets a pressure test (1.5x working pressure, per ASTM B16.5) before shipping.
As a Chinese manufacturer with 10 years supplying European construction and utility markets, we run 8 plate rolling lines and 6 CNC cutting machines, with an annual capacity of 12,000 tons. Our raw plates come from mills certified to ISO 9001, and each batch undergoes a hardness test (Rockwell B 65-80, ASTM E18) to ensure consistency.
We keep 600-800 tons in stock at our Tianjin warehouse, covering sizes from 4" to 36" in diameter and thicknesses 10mm to 50mm. Inventory updates twice daily on our website, and FOB Tianjin shipments for in-stock Carbon Steel Plate Flange leave within 5 days-handy for keeping your customers' projects on schedule.
Orders over 80 tons get a 5.5% discount, plus free sandblasting and 15% of sea freight.
Here's our guarantee: If any flange has dimensional errors exceeding ±1mm or fails to meet ASTM A105 tensile strength standards, we'll replace it within 4 days and cover all shipping costs. For repeat customers, we offer a 3% loyalty discount on top of bulk pricing, and we lock prices for 25 days on confirmed orders to avoid market surprises.
Q235: China's national standard carbon structural steel, with good plasticity and weldability, commonly used in construction, structural parts, etc.
20#: China's high-quality carbon structural steel, with medium carbon content and excellent toughness, suitable for manufacturing pipes, bolts, etc.
A105: American ASTM standard carbon steel forging brand, mainly used for high-pressure pipeline flanges, valves, etc., with balanced strength and toughness.
A36: American ASTM standard carbon structural steel, with similar performance to Q235, widely used in bridges, machinery manufacturing and other fields
Product Name
Carbon Steel Plate Flange
Carbon steel (e.g., Q235B, A36, 20#)
Mechanical Properties
Pressure Rating
Class 150-300
Nominal Diameter
DN15-DN2000 (1/2"-80")
Seal Face Type
Flat Face (FF), Raised Face (RF)
Standards Compliance
GB/T 9112-2010, ASME B16.5 (for export)
Tensile Strength (MPa)
Corrosion Resistance
Application Temp
Q235B Carbon Steel
General (needs coating)
-20°C to 300°C
A36 Carbon Steel
Similar to Q235B
-30°C to 350°C
304 Stainless Steel
Excellent (rust-resistant)
-270°C to 870°C
Service Type
Custom Sizing
Non-standard diameter, thickness (6-100mm)
Surface Treatment
Painting, galvanizing, sandblasting
Certifications
MTR, ISO 9001, Pressure test report
Order Flexibility
MOQ 1 piece, urgent orders (5-7 days)
Recommended Pressure Rating
Key Advantages
Municipal Engineering
Low cost, easy installation
Water Treatment
Class 150-300
Suitable for water/sewage
HVAC Systems
Suitable for low-pressure pipelines
General Industry
Class 150-300
For non-corrosive media
Frequently Asked Questions
Q: Can you provide a detailed product catalog?
A: Sure, we'll send you a digital catalog with specifications, prices, and photos via email. Just let us know your specific needs.
Q: Is there a warranty period for your products? How long is it?
A: Yes, all products have a 12-month warranty. During this period, we'll handle any quality-related issues free of charge.
Q: Do you have experience exporting to our country/region?
A: We have exported to over 50 countries, including the US, EU, Southeast Asia, and the Middle East. We're familiar with local import regulations.
Q: What testing reports can you provide for the products?
A: We can provide reports such as pressure test, chemical composition analysis, and mechanical property test, as per your request.
