1. Material Cost (Approximately 70%-75%)

Square Tube Unit Price: According to market quotes, the tax-inclusive price for 80×80×3.75mm Q235B hot-dip galvanized square tubes is approximately RMB 3,900-4,000/ton. This price includes raw materials (Q235B strip steel), hot-dip galvanizing (zinc layer thickness ≥ 65μm), and basic processing costs (forming and welding).

Waste Control: In actual construction, it is recommended to allow for waste at a rate of 5%-8%, resulting in an actual usage of approximately 1.05-1.08 tons per ton, increasing the material cost to RMB 40,954,320/ton.

Cutting and Welding: For custom lengths or complex joints, cutting costs are approximately RMB 50 per cut, and welding costs are approximately RMB 80 per meter. Taking a standard 6-meter pipe as an example, each ton requires approximately 16 cuts and 20 meters of welding, resulting in a processing fee of approximately 2,000 yuan/ton.

Special Processing: If drilling, bending, or other processes are required, the cost will increase by 300-500 yuan/ton.

Labor Costs: The installation fee for the steel structure frame is approximately 1,500-2,500 yuan/ton, depending on the complexity of the structure. For a medium-difficulty project, the installation fee is calculated at 2,000 yuan/ton.

Machinery Rental: If equipment such as cranes and welders are required, the cost is approximately 300-500 yuan/ton. This fee is negligible for smaller projects.

Logistics Costs: Full truckload shipping from Tianjin to Liaocheng, Shandong costs approximately 5,080 yuan/ton, with LTL shipping fees increasing by 30%-50%.

Value-added tax: calculated at a tax rate of 13%, materials, processing and installation costs are all subject to taxation, and the comprehensive tax is approximately (materials + processing + installation) × 13%.

1. Specifications and Materials

Wall Thickness Differences: For every 1mm increase in wall thickness, material costs increase by approximately 8%-12%. For example, a 100×100×5.0mm square tube costs approximately 150,200 RMB/ton more than a 3.75mm square tube.

Material Upgrade: Q345B is 200,300 RMB/ton more expensive than Q235B, and Q345D (20°C impact energy ≥34J) is 300,500 RMB/ton more expensive.

Hot-Dip Galvanizing: Conventional zinc coating (65μm) costs approximately 3,900 RMB/ton, while zinc-aluminum-magnesium coating (with 35 times greater corrosion resistance) costs approximately 4,430 RMB/ton, representing a 13%-16% increase.

Special Coatings: Fluorocarbon spray coating, electrophoretic paint, and other coatings cost approximately 500,800 RMB/ton and are suitable for highly corrosive environments.

Bulk Purchases: Orders ≥100 tons receive a 5% to 8% discount. For example, square tubes priced at 4,000 yuan/ton can be reduced to 3,700 to 3,800 yuan/ton.

Regional Differences: Prices in North China (Tianjin and Hebei) are 50,100 yuan/ton lower than those in East China, while transportation costs in remote areas increase by 150,200 yuan/ton.

Structural Complexity: The installation fee for complex structures such as trusses and grids is 50% to 100% higher than that for standard frames.

Schedule Requirements: Expedited projects are subject to a 10% to 20% rush fee, especially during peak steel season (March to May, September to November).

1. Lightweight Steel Structure Factory (15-meter span)

Material: 100×100×4.0mm Q235B hot-dip galvanized square tubes, approximately 30 tons.

Cost:

Materials: 30 tons x 4,000 yuan/ton = 120,000 yuan

Processing: 30 tons x 2,000 yuan/ton = 60,000 yuan

Installation: 30 tons x 2,000 yuan/ton = 60,000 yuan

Transportation + taxes: 30,000 yuan

Total: 270,000 yuan (unit price approximately 900 yuan/㎡)

Material: 80×80×3.75mm Q235B hot-dip galvanized square tube, approximately 5 tons.

Cost:

Material: 5 tons x 3,900 yuan/ton = 19,500 yuan

Processing (including punching and bending): 5 tons x 2,500 yuan/ton = 12,500 yuan

Installation (including crane): 5 tons x 2,500 yuan/ton = 12,500 yuan

Transportation + Taxes: 5,000 yuan

Total: 49,500 yuan (approximately 990 yuan/m2 unit price)

V. Practical Suggestions for Cost Reduction

1. Design Optimization:

Use standardized specifications (e.g., 6-meter fixed-length tubes) to reduce cutting losses.

Simplify joint design and prioritize bolted connections to reduce welding costs.

2. Centralized Procurement:

Cooperate with surrounding projects for bulk purchases to achieve price discounts of 5% to 8%.

Sign long-term agreements with manufacturers to lock in prices and mitigate the risk of steel price fluctuations.

3. Construction Management:

Rationally schedule construction to avoid the peak steel season (March-May, September-November).

Use prefabricated production to reduce on-site processing time and labor costs.

4. Material Substitution:

Cold-dip galvanized square pipes can be used for non-load-bearing structures, which are 10%-15% cheaper than hot-dip galvanized pipes.

In less corrosive environments, Q235B can be used instead of Q345B to reduce material costs.

1. Quality Acceptance:

Verify the material list, galvanizing test report (zinc coating thickness ≥ 65μm), and mechanical property data.

The measured weight deviation should be ≤ ±3%. For example, a single 80×80×3.75mm square tube (6 meters) should weigh ≥ 17.4kg.

2. Payment Method:

30% advance payment (covering material purchases), 80% progress payment based on completed volume, and a 5%-10% quality assurance deposit (payable after one year).

A 13% VAT special invoice is required to ensure legal deductions.