Glossary
1 MIN READ
Bending Power
The maximum mechanical or hydraulic force a rolling machine can exert on a workpiece to achieve the desired deformation and target radius.
Technical FAQ
Metal fabricators often need to diversify their production from flat sheets to structural profiles, which requires choosing the right technology to adapt to varying market demands. While plate rolling utilizes wide cylinders to form flat sheet metal into cylinders or cones, angle rolling utilizes specialized, narrower driven shafts to bend structural shapes like beams, pipes, channels, or angles. This clear distinction helps job shops select the exact machinery needed to maximize shop versatility, expand their service portfolio, and capture new commercial opportunities. Davi builds dedicated lines for both applications, engineering systems that handle plates up to 400 mm (15.75 inches) thick and structural sections like beams up to 1,200 mm (47.24 inches) in height.
Eliminating material waste and avoiding secondary cutting operations is a primary goal for high-productivity job shops looking to protect their margins. A flat end is the straight, unbent section left at the leading and trailing edges of a plate because the material cannot physically reach the exact tangent contact point between the machine rolls. Minimizing this straight section directly reduces material scrap and eliminates the time-consuming process of pre-bending plates on a separate press brake, thereby accelerating overall floor cycle times. Utilizing Davi all-rolls-drive technology ensures the plate can be positioned precisely at the tangent point to achieve the shortest flat end possible without compromising safety.
Fabricators working on high-precision applications like pressure vessels must ensure perfect roundness from the absolute edge of the plate to comply with strict safety codes. Pre-bending is the preliminary manufacturing step where the leading and trailing edges of a sheet are bent to the target radius before continuous rolling begins. Executing this properly minimizes the flat end, ensures structural integrity at the subsequent weld seam, and reduces the need for manual grinding or expensive re-rolling calibration. Davi 4-roll and variable-axis 3-roll machines are engineered to execute high-tonnage pre-bending safely and accurately in a single automated cycle.
Dealing with high-yield structural steels can cause unexpected spring-back, leading to inconsistent part dimensions and slowed production lines. Yield strength is the specific stress threshold where a metal permanently deforms, meaning higher yield materials require significantly more bending power from the rolls to transition from elastic to plastic deformation. Recognizing your material's specific yield properties allows you to correctly gauge machine capacity, preventing equipment overload while ensuring accurate dimensional results. The Davi iRoll control system features a comprehensive material library that automatically factors in yield strength to calculate exact bending programs.
Engineering teams working with advanced alloys must carefully manage forces to avoid cracking or fracturing high-strength materials during tight-radius forming. Ultimate tensile strength is the maximum amount of tensile stress a material can withstand before structural failure or complete breaking occurs. Knowing the UTS ensures that multi-pass programs are correctly calibrated to form the material progressively without exceeding its mechanical boundaries, protecting both the workpiece and the machine components. Davi’s technical division utilizes advanced Finite Element Method (FEM) studies to evaluate material behavior against machine capabilities before production begins.
Inaccurate radius tracking due to material elasticity leads to continuous trial-and-error adjustments, resulting in costly scrap and slow assembly lines. Spring-back is the natural tendency of a metal plate or profile to partially return toward its original flat shape after the forming force is released, caused by elastic recovery. Accurate spring-back prediction allows the control system to over-bend the plate precisely, achieving the exact target radius on the first attempt without wasting time or material. Davi offers dedicated Spring-Back Software that analyzes material properties to eliminate manual guesswork and minimize test scrap.
Mass-production facilities require automated processing with minimal reliance on highly skilled operator intervention to remain competitive. A 4-roll machine uses a top and bottom roll to securely pinch the plate, while two side rolls travel up to execute the bending force. It provides total material control throughout the cycle, allows for fully CNC-automated production lines, and makes the initial squaring process simple and safe. Davi MCA and MCB 4-roll lines are the global standard for high-productivity automation, offering rapid cycle times for job shops worldwide.
Reducing the straight flat end on thick plates requires moving the bending rolls as close to the pinching point as possible. A flat gearbox features an eccentric rotation axis that avoids physical interference between hydraulic motors and the top roll cylinder shaft. It allows the side rolls to travel closer to the top roll (minimum gauge), achieving an exceptionally short flat end without compromising machine frame capacity. Davi exclusive flat gearboxes are a core component in achieving precision pre-bending on variable-axis machines.
Large-scale corporations require risk mitigation against extended downtime caused by long lead times for custom heavy components. Instead of a single custom gearbox, a multi-gearbox configuration connects multiple standard gearboxes to a heavy-duty reduction gear driving the top roll. If one gearbox component fails, the machine can continue operating at a reduced torque level, eliminating catastrophic production downtime while replacement parts are sourced quickly from standard stock. Davi implements this design on machines with pressing capacities exceeding 3,000 tons to protect large-scale infrastructure projects.
Unplanned equipment outages interrupt production schedules and impact a job shop's profitability. FFM is a dedicated diagnostics and predictive maintenance software module that continuously monitors component lifespans and system parameters. It displays clear alerts and warning messages on the console, allowing maintenance teams to address minor component wear before it results in costly downtime. Davi integrates FFM applications into its advanced control environments to maximize equipment uptime.
The capacity of a Davi plate roll is defined by its ability to exert the necessary bending force for specific plate thicknesses, widths, and material yield strengths, ensuring precise geometry during both pre-bending and continuous rolling. On 4-roll machines, such as the Davi MCA and MCB series, optimal clamping by the bottom roll enables pre-bending to achieve the tightest diameters per capacity on the market, reaching 1.1 times the top roll diameter. For heavy-duty applications, 3-roll variable-axis machines like the Davi MAV feature independently moving side rolls and a vertical top roll, providing maximum leverage and force distribution to maintain short flat ends and strict dimensional tolerances.
Industrial fabricators frequently face hidden costs when choosing low-cost forming equipment, including frequent downtime, inaccurate tolerances, long component lead times, and premature machine obsolescence. Davi eliminates these operational risks through 100% Made in Italy engineering based in Cesena, backed by triple ISO certifications (ISO 9001, ISO 14001, ISO 45001), immediate delivery options via ready stock, and robust financial stability. Over a 10-year Total Cost of Ownership (TCO) evaluation, Davi systems drastically outperform lower-cost alternatives by incorporating non-proprietary global components from Siemens, ABB, and Eaton, an inventory of over 11,000 spare part items, and dedicated 24/5 technical support. By combining heavy-duty mechanical design with advanced R&D, Davi guarantees operational continuity, precise repeating geometry, and higher long-term equipment resale value.
On standard 4-roll machines (Davi MCA and MCB series), the tightest achievable internal diameter is 1.1 times the top roll diameter. This performance is made possible by planetary side roll guides, which pivot around a fixed axis to wrap the plate tightly around the top roll. On machines equipped with interchangeable top roll systems, smaller diameter top rolls can be installed to achieve even tighter cans, slightly derating machine capacity to compensate for roll deflection.
Installed power depends on machine tonnage and drive configuration, but conventional hydraulic plate rolls draw continuous energy through central power packs even during standby phases. Davi resolves high energy overheads through the MCE e-POWER, the world's only complete line of fully electric 4-roll plate bending machines. Replacing central hydraulics with independent servomotors and dedicated actuators, the MCE features an automatic Start&Stop system that ensures zero energy absorption during standby. Power is consumed exclusively when an axis moves, achieving up to a 65% energy reduction compared to standard hydraulic plate rolls (e.g., cutting benchmark annual consumption from 2,682.2 kWh/year down to 929.3 kWh/year) while reducing operational noise levels by 40% (down to 58 dB).