Set 1
Q: What's the difference between Q235B and Q345 for these beams/columns?
A: Q235B and Q345 are both Chinese standard carbon steels but differ primarily in strength and application scope. Q235B is a low-carbon structural steel with a minimum yield strength of 235 MPa, while Q345 is a low-alloy high-strength steel with a higher minimum yield strength of 345 MPa. Q235B offers better weldability and formability, making it ideal for light to medium-load structures like small workshops or residential frames. Q345 provides superior load-bearing capacity and toughness, suiting heavier applications such as industrial columns, large-span beams, or structures in seismic zones. Chemically, Q345 contains alloying elements like manganese and silicon to boost strength, whereas Q235B has a simpler composition. Cost-wise, Q345 is slightly more expensive, but its strength efficiency often offsets costs for high-load projects.
Q: Are these light welded H-shapes good for prefab buildings?
A: Yes, light welded Q235B/Q345 H-shaped beams and columns are excellent for prefabricated buildings. Their "light" design means they are lightweight yet structurally rigid, reducing transportation and on-site lifting costs-key for prefab's efficiency. The welded construction ensures consistent quality, which is critical for modular components that need precise fitting. Both Q235B and Q345 have strong weldability, allowing factory pre-assembly of frames that can be quickly joined on-site, cutting construction time. Their H-shape provides balanced strength for floor, wall, and roof supports in prefab homes, offices, or temporary facilities. Additionally, their compatibility with other prefab materials (like steel panels) makes them a versatile choice for modular construction.
Q: What sizes do your light welded H-beams/columns come in?
A: We offer a range of sizes tailored for light structural needs, with variations in web height (H), flange width (B), and thicknesses (t1 for flange, t2 for web). Common web heights range from 100mm to 400mm, while flange widths typically span 80mm to 200mm-keeping them "light" compared to heavy hot-rolled H-shapes. Flange thicknesses (t1) start at 4mm and go up to 12mm, and web thicknesses (t2) range from 3mm to 8mm. Popular standard sizes include H100×80×4×6, H150×100×5×7, H200×120×5×8, H300×150×6×9, and H400×200×8×10. We also provide custom sizes within these parameter ranges to fit unique prefab or light industrial designs. Our sales team can share a detailed size-weight chart for quick reference.
Q: How is the welding quality of these H-shapes guaranteed?
A: We maintain strict welding quality control for our light welded H-beams/columns. First, we use low-carbon/mild steel plates (Q235B/Q345) with low carbon equivalents, minimizing welding cracks. Our welders are certified to GB/T 6519 standards, ensuring professional operation. We use advanced submerged arc welding (SAW) for most joints-this method produces deep, uniform welds with high strength and minimal defects. Each weld undergoes non-destructive testing (NDT): ultrasonic testing (UT) checks for internal flaws, and visual inspection verifies surface smoothness and joint penetration. We also conduct tensile and bend tests on sample welds to confirm they meet Q235B/Q345's mechanical requirements. Every batch includes a welding quality report for customer verification.
Q: What's the lead time for custom light welded H-shapes?
A: Lead time for custom light welded Q235B/Q345 H-beams/columns depends on size, quantity, and customization complexity. For standard light sizes (e.g., H150×100, H200×120) and small quantities (20-50 tons), lead time is 2 to 3 weeks after order confirmation. For custom sizes (e.g., non-standard web/flange dimensions) or medium quantities (50-100 tons), it extends to 3 to 4 weeks, as it requires adjusting welding jigs and plate cutting. Large orders (over 100 tons) may take 4 to 5 weeks to ensure consistent quality. If you need additional processing (e.g., hole drilling, beveling), add 1 to 2 days. International shipping adds 1 to 3 weeks for sea freight and customs. Contact our team with your specs for a precise timeline.
Set 2
Q: Can these H-shapes be used for mezzanine floors?
A: Absolutely, light welded Q235B/Q345 H-beams and columns are perfect for mezzanine floors. Mezzanines require structures that are strong enough to support floor loads (people, equipment, storage) but lightweight to avoid overburdening the main building. Q235B works well for small mezzanines (e.g., 50-100㎡) with light loads, while Q345 is better for larger mezzanines or those holding heavy items (e.g., industrial storage). The H-shape's wide flanges distribute weight evenly, reducing deflection and ensuring floor stability. Their welded construction provides rigid connections between beams and columns, critical for mezzanine safety. Additionally, their slim profile saves vertical space, maximizing headroom under the mezzanine-an important factor for warehouses or retail spaces.
Q: Do you offer surface treatment for rust protection?
A: Yes, we provide multiple surface treatments to protect light welded H-beams/columns from rust. The most common option is hot-dip galvanizing: beams are dipped in molten zinc, forming a thick, durable coating that resists corrosion for 15-20 years-ideal for outdoor or humid environments (e.g., warehouses near coasts). We also offer spray painting: options include epoxy primer (for indoor protection during storage/transport) or epoxy-polyurethane topcoats (for long-lasting indoor/outdoor use, available in custom colors). For budget-friendly needs, we provide phosphating + passivation, a chemical treatment that forms a rust-resistant film under paint. The default finish is a black oxide layer (from welding/cooling), suitable only for dry indoor storage. You can select the treatment based on your project's environment and lifespan requirements.
Q: How do I choose between Q235B and Q345 for my project?
A: Choose between Q235B and Q345 based on your project's load requirements, span length, and budget. Opt for Q235B if you're building light structures with low to medium loads-e.g., small prefab homes, residential mezzanines, or non-load-bearing columns. It's more affordable and easier to weld/form, making it cost-effective for simple designs. Choose Q345 if your project involves heavy loads, long spans, or harsh conditions-e.g., industrial mezzanines with equipment, large prefab warehouses, or seismic-prone areas. Its higher yield strength lets you use smaller section sizes (reducing weight and space), offsetting its slightly higher cost. If you're unsure, share your project's load calculations or span details with our team-we can recommend the right grade based on structural needs.
Q: Can these H-shapes be drilled or cut on-site easily?
A: Yes, light welded Q235B/Q345 H-shapes are easy to drill and cut on-site, which simplifies installation. Both grades are low-carbon/low-alloy steels with uniform hardness, so standard industrial drills (high-speed steel or carbide bits) work for drilling holes-no special equipment is needed for most sizes (web thickness ≤8mm, flange thickness ≤12mm). For cutting, portable angle grinders with cutoff wheels or plasma cutters handle straight cuts quickly; band saws are ideal for more precise cuts. Their welded structure has no brittle zones, so cutting/drilling won't cause cracking or deformation. This on-site workability is a big advantage for prefab projects or mezzanines, where last-minute adjustments (e.g., fitting around pipes) are common. We also offer pre-drilling/cutting if you have exact specs, saving on-site time.
Q: Do you ship these light welded H-shapes internationally?
A: Yes, we provide international shipping for light welded Q235B/Q345 H-beams and columns to support global prefab and construction projects. We partner with freight forwarders specializing in light steel cargo, offering flexible shipping: sea freight (most cost-effective for large quantities, using containers or bulk holds), rail freight for landlocked regions, and air freight for urgent small orders. We handle all export paperwork, including commercial invoices, packing lists, bills of lading, certificates of origin, and mill test reports (MTRs)-critical for customs clearance. Our packaging (steel-strapped bundles on wooden skids, waterproof wrapping) protects against damage during transit. We've shipped to regions like Southeast Asia, the Middle East, Africa, and Europe, and our team can provide freight quotes based on your delivery address and order volume.
Set 3
Q: What's the weight range of these "light" welded H-shapes?
A: The weight of our light welded Q235B/Q345 H-beams/columns varies by size but stays within a range suitable for light structural use. Smaller sizes (e.g., H100×80×4×6) weigh approximately 8-12 kg per meter. Medium sizes (e.g., H200×120×5×8) typically range from 18-25 kg per meter. Larger light-duty sizes (e.g., H400×200×8×10) weigh around 45-55 kg per meter-still significantly lighter than heavy hot-rolled H-shapes (which can exceed 100 kg/m). The "light" label refers to their weight relative to their load capacity: they offer high strength-to-weight ratios, making them efficient for projects where weight is a concern (e.g., prefab, mezzanines). We provide a weight-per-meter chart for all sizes, and our team can calculate total order weight based on your chosen specs and lengths.
Q: Are these H-shapes compliant with Chinese steel standards?
A: Yes, our light welded Q235B/Q345 H-beams and columns fully comply with relevant Chinese national standards. The base materials meet GB/T 700 (for Q235B carbon structural steel) and GB/T 1591 (for Q345 low-alloy high-strength steel), ensuring their chemical composition and mechanical properties are up to code. The welding process adheres to GB/T 5117 (for carbon steel welding rods) and GB/T 12470 (for submerged arc welding wires), guaranteeing weld quality. The dimensional accuracy of the H-shapes follows GB/T 11263, which specifies tolerances for welded H-section steel. Each shipment includes certification documents (MTRs, welding reports) that reference these standards, so you can verify compliance for project inspections or permits. We also conduct regular third-party audits to maintain standard alignment.
Q: Can I get these H-shapes with pre-drilled holes?
A: Yes, we offer pre-drilled holes for light welded Q235B/Q345 H-beams and columns to simplify on-site assembly. We use CNC drilling machines for precision-hole diameters can range from 10mm to 50mm, with a positional tolerance of ±2mm, ensuring alignment with bolts or connectors. You can specify hole locations (e.g., along flanges for beam-column joints, on webs for bracing), spacing, and quantities when placing your order. Pre-drilling eliminates the need for on-site drilling equipment and labor, reducing installation time and the risk of measurement errors. This service is especially popular for prefab projects, where modular components need exact hole alignment. There is a nominal fee for pre-drilling, and we can provide drawings for your approval before production.
Q: What's the difference between welded and hot-rolled H-shapes?
A: Welded and hot-rolled H-shapes differ in manufacturing, size flexibility, and weight. Hot-rolled H-shapes are formed by rolling steel at high temperatures into one piece, offering uniform grain structure but limited size options (mostly large, heavy sections). Welded H-shapes are made by cutting steel plates into webs/flanges and welding them together, allowing custom sizes-ideal for light, non-standard specs. Welded H-shapes are lighter (critical for prefab/mezzanines) and have tighter dimensional tolerances for precise fitting. Hot-rolled shapes have higher load capacity for heavy structures but are more expensive and harder to customize. For light to medium-load projects needing flexibility, welded H-shapes (like ours) are better; for heavy industrial loads, hot-rolled may be preferred.
Q: Do you provide samples before bulk ordering?
A: Yes, we are happy to send samples of our light welded Q235B/Q345 H-beams/columns to help you verify quality before a bulk order. Samples are typically 30-60cm long sections of your chosen size and grade, allowing you to inspect welding quality (smooth joints, no cracks), dimensional accuracy (flange/web thickness), and surface finish. You can also test them for weldability or hardness if needed. There is a small cost for samples and shipping, but this fee is deducted from your subsequent bulk order. To request samples, just share your desired grade (Q235B/Q345), size (e.g., H200×120×5×8), and shipping address with our sales team. We aim to dispatch samples within 3-5 business days to help you make an informed decision.
Set 4
Q: Are these H-shapes suitable for temporary construction sites?
A: Yes, light welded Q235B/Q345 H-beams and columns are perfect for temporary construction sites. Their lightweight design makes them easy to transport, assemble, and disassemble-key for temporary structures like site offices, worker dormitories, or storage sheds. Q235B is cost-effective for short-term use (6-12 months), while Q345 adds durability for longer temporary projects (1-3 years). The welded H-shape provides enough strength to withstand wind and rain, ensuring stability on-site. They are also reusable: after one project, they can be disassembled and transported to another site, reducing material waste and costs. Additionally, their compatibility with quick-connect fittings speeds up assembly, getting temporary facilities operational faster.
Q: How are these H-shapes packaged for delivery?
A: We package light welded Q235B/Q345 H-beams/columns to ensure safe delivery. Beams/columns are grouped into bundles by size and length-usually 8-15 pieces per bundle (depending on weight, to keep bundles manageable). Each bundle is secured with 2-3 high-strength steel straps (1-1.5 inches wide) at both ends and the middle to prevent shifting. The ends of each piece are capped with plastic or metal protectors to avoid dents during handling. For long-distance or sea shipping, bundles are placed on wooden skids to elevate them above moisture and facilitate lifting with forklifts. We add waterproof plastic wrapping for shipments to rainy or humid regions. For small orders or custom pieces (e.g., pre-drilled beams), we use steel crates for extra protection. Our packaging minimizes damage during loading, transit, and unloading.
Q: What's the price per ton for these light welded H-shapes?
A: The price per ton of light welded Q235B/Q345 H-beams/columns depends on grade, size, quantity, and surface treatment. Q235B is generally more affordable, ranging from $500-$650 per ton for standard sizes. Q345, being high-strength, costs slightly more-$550-$700 per ton. Smaller sizes (e.g., H100×80) are at the lower end, while larger light sizes (e.g., H400×200) are at the higher end. Surface treatments add cost: hot-dip galvanizing adds $100-$150 per ton, while painting adds $50-$80 per ton. Bulk orders (100+ tons) qualify for 10-15% volume discounts. Prices fluctuate slightly with raw material costs, so quotes are valid for 7-10 days. Contact our sales team with your grade, size, quantity, treatment, and delivery location for an accurate, detailed quote.
Q: Can these H-shapes be used for retail store interiors?
A: Yes, light welded Q235B/Q345 H-beams are great for retail store interiors, especially modern or industrial-style spaces. They are often used as exposed ceiling beams to create a sleek, contemporary look-their slim H-profile adds visual interest without overwhelming the space. Q235B works for small to medium stores, supporting lightweight ceiling fixtures or signage. Q345 is suitable for larger stores needing to span wider areas (e.g., 8-12 meters) without extra columns, maximizing floor space for displays. Their welded finish can be left raw (for industrial aesthetics) or painted (to match store decor). They are also used for mezzanine floors in two-story retail spaces, providing safe, unobtrusive support. Their light weight avoids straining the store's existing structure.
