Circular blades for copper strip cutting

In metal slitting operations, the side gap (also called lateral clearance) between slitter blades is one of the most critical process parameters. If the side gap is too large, the cut edge becomes jagged with burrs. If the side gap is too small, the blades rub against each other, generate heat, and may even chip. So, is there a universal calculation formula to quickly determine a reasonable side gap value? Mingbai Mechanical Tool Technology Co., Ltd., based on domestic and international standards and years of practice, provides you with a scientific calculation method.   1. The Universal Calculation Formula for Side Gap   The core of side gap calculation is the "material thickness percentage method," with the formula as follows:   Side Gap C = K × t     Where:   · C = Side gap (mm) · K = Gap coefficient (dimensionless) · t = Thickness of the material being sheared (mm)   Principles for selecting K value:   · Hard and brittle materials (silicon steel, high-carbon steel): K = 8%-12% · Soft and tough materials (low-carbon steel, copper, aluminum): K = 5%-7% · Medium hardness materials (ordinary carbon steel, stainless steel): K = 6%-10% · Ultra-thin materials (<0.3mm): K = 3%-5%   2. Recommended K Values for Different Materials     Ordinary carbon steel (Q235, SPCC, DC01): K = 6%-8%. Use the lower limit for thin materials (0.5mm at 6%) and the upper limit for thick materials (3mm at 8%). Circular blades for ordinary carbon steel slitting should be set according to this coefficient.   Stainless steel (304, 316, 430): K = 8%-10%. Stainless steel has severe work hardening, so a larger gap reduces friction between the edge and the material. Wear-resistant circular blades for stainless steel strip slitting are recommended with K = 9%.   Silicon steel: K = 10%-12%. The material is hard and brittle, requiring a larger gap to reduce impact. Alloy blades for silicon steel slitting are recommended with K = 11%.   Non-ferrous metals such as copper and aluminum: K = 4%-6%. Soft metals are sensitive to gap; too large a gap causes edge stringing. Circular blades for copper strip cutting are recommended with K = 5%.   High-strength steel: K = 8%-10%. Balancing hardness and toughness, the gap should not be too small. Custom blades for automotive panel slitting are recommended with K = 9%.   3. Other Factors Affecting K Value   1. Equipment rigidity   For equipment with good rigidity, the K value can be taken at the lower limit. For equipment with poor rigidity, use the upper limit to absorb impact.   2. Shearing speed   At high speeds (>100m/min), the K value should be reduced by 10%-15% compared to the conventional value to reduce vibration and temperature rise.   3. Blade material   Carbide blades, due to their high hardness and low deformation, can use a K value 5%-10% smaller than high-speed steel blades. High-hardness alloy blades can have a slightly smaller gap under the same working conditions.   4. Adjustment Method in Practical Application   Step 1: Calculate the initial gap using the formula   For example, for shearing 2.0mm thick 304 stainless steel, t = 2.0mm, K = 9%, then C = 2.0 × 9% = 0.18mm.   Step 2: Verify through trial cutting   Slit a section of material at normal speed and inspect the cut edge with a magnifying glass:     · Small, uniform burrs → gap is appropriate · Large burrs with tearing marks → gap is too large; reduce by 0.01-0.02mm · Whitened edge with powder → gap is too small; increase by 0.01-0.02mm   Step 3: Record the optimal value   Record the verified optimal gap value on the process card for direct use next time.   5. Five Precautions for Gap Adjustment   1. After each blade or material change, the gap must be re-measured and adjusted. 2. Use a feeler gauge for measurement; do not estimate by "feel."     3. After upper and lower blades are resharpened, the outer diameter becomes smaller, and the gap must be reset. 4. In multi-blade slitting, the gap for each blade should be consistent. 5. The gap adjustment precision for precision mechanical blades should be controlled within ±0.005mm.   6. Mingbai Technology's Gap Setting Services   Mingbai Mechanical Tool Technology Co., Ltd. provides side gap calculation and optimization services:   · Free calculation of recommended gap values based on your material, equipment, and speed. · On-site guidance for gap adjustment and trial cut verification. · Supply of high-precision feeler gauges and gap measurement tools. · For custom slitter blades, the gap value can be preset according to your working conditions.     7. Case Study   A stainless steel strip slitting plant used the same set of wear-resistant circular blades for stainless steel strip slitting to shear 1.0mm and 2.0mm stainless steel. The operator consistently used a 0.08mm gap for both thicknesses. As a result, the 1.0mm material cut well, but the 2.0mm material had severe burrs. Mingbai engineers calculated using the formula: 1.0mm × 9% = 0.09mm, 2.0mm × 9% = 0.18mm. After setting the gaps separately, the cut edge quality met standards for both thicknesses.   Conclusion   Although there is no "universal formula" for slitter blade side gap, the "C = K × t" calculation method covers the vast majority of working conditions. The key is selecting the K value — based on material, equipment, and speed, then fine-tuning through trial cuts. Mingbai Technology is ready to help you find the most suitable gap value with professional calculations and on-site services. Website: www.mingbaiblade.com

In slitting production, many users encounter this puzzle: the same equipment and the same set of circular blades work perfectly on 0.5mm material, but when switching to 1.5mm of the same material, problems such as burrs, tearing, and even chipping occur. They then ask: when shearing different thickness materials with circular blades, is separate customization of the edge necessary? Mingbai Mechanical Tool Technology Co., Ltd. answers: Not necessarily every time, but when the thickness difference exceeds a certain range, customization is necessary. This article provides a detailed analysis.   1. The Impact of Thickness Differences on Edge Requirements   1. Relationship between edge angle and cutting resistance   The edge angle (wedge angle) determines the sharpness and strength of the blade:   · Thin materials (<0.5mm) require a small angle (18°-22°) to maintain sharpness; otherwise, they won't cut through. · Thick materials (>2mm) require a large angle (25°-30°) to ensure edge strength; otherwise, chipping occurs.   If circular blades for thin sheet slitting are used to cut thick plates, the edge is too sharp and prone to chipping. If high-speed steel blades for thick plate shearing are used to cut thin sheets, the edge is too dull, resulting in large burrs on the cut edge.     2. Edge radius and material deformation   The edge radius (passivation value) determines the degree of extrusion when penetrating the material:   · Thin materials require an extremely small edge radius (R≤0.005mm) to minimize material deformation. · Thick materials require a slightly larger edge radius (R=0.01-0.02mm) to enhance edge impact resistance.   3. Chain reaction of gap and overlap changes   When thickness changes, the blade gap and overlap must be reset. However, if the edge design is unreasonable, even adjusting parameters will make it difficult to achieve the ideal cutting effect.     2. When Is Separate Edge Customization Necessary?   1. Thickness difference exceeds 3 times   For example, if the same equipment is used to cut both 0.3mm and 1.0mm materials, the edge angle and radius requirements are completely different. Two sets of stainless steel strip slitting circular blades should be customized.   2. Completely different material properties   Even with the same thickness, different materials (e.g., copper strip vs. stainless steel strip) have different edge requirements. Circular blades for copper strip cutting require extremely sharp, anti-adhesion edges, while alloy blades for silicon steel slitting require wear-resistant edges.   3. Different equipment rigidity   Old equipment with poor rigidity requires a duller edge to absorb impact; new equipment with sufficient rigidity can use a sharper edge. If two sets of equipment share the same high-precision custom blades, the results will inevitably differ.   3. When Is Customization Not Necessary?   · Thickness difference within ±50% (e.g., 0.8mm and 1.2mm): use a medium edge angle and adjust the gap. · Both are within the thin material range (0.3-0.8mm) or within the thick material range (1.5-3mm): only fine-tuning the gap is needed; no separate edge customization is required.     4. Mingbai Technology's "One Material, One Edge" Customization Solution   Mingbai Mechanical Tool Technology Co., Ltd. provides targeted customization services:   1. Customer provides material grade, thickness range, and equipment model. 2. Mingbai engineers calculate the optimal combination of edge angle, radius, and clearance angle. 3. Produce the corresponding custom slitter blades and attach an edge inspection report.     If the same equipment needs to cut multiple thicknesses, we can provide a "multi-edge blade set for different thicknesses" with laser marking on the blade indicating the recommended thickness to avoid misuse.   5. Case Comparison   A copper strip slitting plant used the same set of wear-resistant circular blades to cut 0.2mm and 0.8mm copper strips. Cutting 0.2mm produced smooth edges, but cutting 0.8mm resulted in severe burrs and halved blade life. Mingbai Technology customized two sets of slitting circular blades with different edges: 18° sharp edge for thin material, 25° wear-resistant edge for thick material. By switching blades when changing materials, burrs disappeared, and total blade life increased by 40%.     Conclusion   When shearing different thickness materials with circular blades, separate edge customization is not always necessary. However, when the thickness difference exceeds 3 times, material properties differ, or equipment rigidity varies significantly, customizing the edge is essential to ensure cutting quality. Mingbai Technology is committed to providing professional "one material, one edge" matching solutions, ensuring you get excellent results whether cutting thin or thick materials.   Website: www.mingbaiblade.com