The Critical Role of Steel Strip Shears in Second-Hand Welded Pipe Machines​

Steel strip shears are essential pre-forming components in second-hand welded pipe machines, responsible for cutting steel coils into fixed-length strips before entering the forming section. Their cutting precision and efficiency directly affect the material utilization rate and the subsequent forming quality of welded pipes.​

Cutting Precision Assurance​

In second-hand welded pipe machines, high-performance steel strip shears achieve a cutting length tolerance of ±0.5mm for strips with widths ranging from 100mm to 1200mm, and a cutting edge flatness of ≤0.1mm/m. This precision ensures that the strips can be accurately fed into the forming stands without edge misalignment, which is crucial for maintaining the roundness of the pipe (deviation ≤1% of the outer diameter) during the bending process. For example, when processing DN150 welded pipes, a 0.3mm deviation in strip length can cause a 0.8mm roundness error in the final pipe, leading to a 15% increase in scrap rate. In contrast, worn shears in unmaintained second-hand machines may have a cutting tolerance of ±2mm, significantly reducing product qualification rates.​

Material Utilization Optimization​

Well-calibrated steel strip shears in second-hand welded pipe machines support "nesting cutting" for irregularly shaped coils, reducing material waste by 8-12% compared to traditional fixed-length cutting. For instance, when processing steel coils with edge defects (e.g., wavy edges within 2mm), the shear can automatically adjust the cutting path to avoid defective areas, ensuring that the usable part of the coil is fully utilized. This is particularly valuable for high-cost materials such as stainless steel (304 grade), where even a 5% reduction in waste can save ​

3,000−5,000 per month for a medium-sized production line.​

Production Efficiency Enhancement​

Modernized steel strip shears in refurbished second-hand welded pipe machines feature a dual-station design, allowing one station to cut while the other loads new coils. This reduces coil changing time by 60-70% (from 15 minutes to 4-5 minutes per coil), enabling the machine to maintain a continuous production speed of 20-30m/min. Additionally, the shear’s automatic blade gap adjustment (range: 0.05-0.2mm, adjusted based on strip thickness) eliminates manual setup, further shortening the preparation time for different strip specifications.​

Maintenance Guidelines​

To ensure optimal performance of steel strip shears in second-hand welded pipe machines:​

• Inspect the shear blades daily for wear; replace blades when the cutting edge wear exceeds 0.2mm or when burrs appear on the strip edge.​

• Check the blade gap weekly using a feeler gauge; adjust if the gap deviates by more than 0.03mm from the recommended value (typically 10-15% of the strip thickness).​

• Lubricate the shear’s drive gears and sliding rails monthly with industrial gear oil (ISO VG 220) to reduce friction and prevent jamming.​

• Calibrate the length measurement system quarterly using a laser length meter to ensure cutting length accuracy.​

For second-hand welded pipe machines processing high-strength steel strips (≥550 MPa), upgrading to tungsten carbide-coated blades can extend blade life by 2-3 times and maintain cutting precision for longer periods.​

For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier：www.usedpipemill.com​