Cold beveling is a chip removal process used to prepare the ends of pipes and sheet metal, achieving precise bevels and clean edges without generating heat. Unlike thermal cutting, it does not produce a heat-affected zone (HAZ): the mechanical properties of the material remain unchanged and the joint is ready for welding in compliance with regulations. The process is performed with pipe beveling machines (for pipes) and plate beveling machines (for sheet metal), machines available in both portable versions for the construction site and with automatic feed for series production.
How cold mechanical beveling works
A rotating insert tool or face mill removes material from the edge of the tube or sheet metal without ever melting the metal. The piece remains at room temperature throughout the process: there is no heat input, combustion, or use of plasma. The resulting edge is geometrically precise, with angle, height, and tolerances maintained piece by piece, free of oxidation, and immediately weldable without additional cleaning steps. The cutting geometry is determined by the insert and the tool’s inclination: by replacing them, it is possible to switch from a V-bevel to a J-bevel without modifying the machine.
Cold beveling vs. thermal cutting: the key differences
Thermal cutting—plasma, oxyfuel, and laser—heats the metal to very high temperatures in a localized area. This area, while not completely melting, undergoes microstructural changes: this is the heat-affected zone (HAZ), which can compromise the material’s characteristics and become a weak point in the welded joint.
Practical consequences:
- Oxidized edges requiring grinding before welding
• Geometric deformation of the edge, especially on thin sheets
• Microstructural alteration in sensitive alloys such as duplex, super duplex, and Inconel
Cold mechanical beveling, on the other hand, does not generate HAZ. The edge is clean, precise, and stable, without the need for additional machining.
Types of Chamfer and When to Use Them
The UNI EN ISO 9692 standard defines the geometries of weld joints based on the process, thickness, and material. Four main types are used in industrial practice:
- V-bevel: Typical 60° angle, for thicknesses from 5 to 20 mm. The most common, suitable for single-sided TIG and MIG/MAG welding.
- X-bevel: Double bilateral V, for thicknesses greater than 15 mm. Reduces the volume of filler material compared to a single V.
- J-bevel: Profile with a rounded radius, for thicknesses greater than 20 mm. Requires precision machining: thermal cutting cannot meet the tolerances required by the standard.
- U-bevel: Full U, for high thicknesses in nuclear and high-pressure applications.
The standard requires stringent geometric tolerances, which vary depending on the type of joint and the execution class. For J- and U-bevels, cold mechanical beveling is the only technically adequate solution. Discover our guide to bevel geometries and related tools.
Cold beveling: industrial applications
Cold beveling is the operational standard in all contexts where joint quality is critical, regulated, or subject to certification.
Oil & Gas and pipelines: Pipelines operate at high pressures and in corrosive environments. A residual HAZ can trigger fatigue cracking or selective corrosion over time, compromising the system’s sealing.
Naval and offshore: Large structures, often made of high-strength steels or special alloys. Processing generally takes place on site with portable machines.
Boilerwork and heat exchangers: Series machining of small-diameter pipes, where consistent chamfer geometry is crucial to the final quality of the joint.
Petrochemical and nuclear: EN 1090 and ISO 3834-certified plants, where edge preparation is an integral part of the quality documentation.
Pipe Beveling: How It Works and Which Machines to Use
Pipe beveling machines are anchored to the pipe using an internal expansion locking system (the mandrel expands against the inside wall of the pipe) or external clamping jaws – useful when access to the inside is not possible, such as on heat exchanger tube sheets.
Once centered, the machine rotates around the axis of the pipe and creates the chamfer in a single circular pass. In most cases, GBC machines operate directly in place, without the need to remove the pipe from the system.
GBC pipe beveling machines cover diameters from Øi 10 mm (Mini K OD, excellent for working on small-diameter pipes where internal clamping is not possible) up to 40″ – 1016 mm (Hypermaxi 20_40 with optional extension kit, for large pipelines and offshore plants). The Mini, TC, and Boiler series are suitable for heat exchangers, boilers, and industrial maintenance on small and medium-diameter pipes; the Supermaxi and Hypermaxi series are suitable for pipelines and process plants. Motors are available in pneumatic, electric, brushless, battery-powered, or hydraulic versions.
For more information on choosing a model, consult our complete guide to pipe cutting and beveling machines.
Sheet Metal Beveling: How It Works and Which Machines to Use
Plate beveling machines advance along the edge of the sheet metal via a system of guide rollers that holds the machine in position while the cutter removes material without generating sparks. The bevel angle can be adjusted directly on the tool or by tilting the cutter head.
The same machine—with the appropriate insert—can perform variable-angle V-bevels, radius-profile J-bevels, butting, and slitting, covering most preparations required in heavy metal fabrication, shipbuilding, and boilermaking.
GBC plate beveling machines process thicknesses from 6 to 120 mm. The Challenge (6-40 mm) is the portable machine, ideal for quick jobs or ATEX environments. The Compact Edge covers thicknesses up to 60 mm with a variable-angle head (15°–60°); the Basic Edge 50 achieves the same range with automatic feed. The Edge 80 and Multiedge 80 reach 120 mm and integrate J-bevels, butting, and splaying for heavy, naval, and nuclear boilerwork.
To choose the right machine based on the type of bevel and production volume, read how to choose a sheet metal beveling machine.
Materials that can be machined with cold beveling
Cold beveling is applicable to all common industrial metals: carbon steel, stainless steel, duplex steel, super duplex steel, Inconel steel, titanium, and aluminum.
Heat-sensitive alloys benefit most from this process:
- Stainless steel: Thermal cutting creates a chromium-depleted zone at the edge, susceptible to intergranular corrosion. Beveling preserves the chemical composition of the edge.
- Duplex and super duplex: The two-phase microstructure (austenite-ferrite) is altered by heat, compromising the mechanical properties and corrosion resistance in aggressive environments such as oil and gas.
- Inconel and nickel-based alloys: Highly sensitive to thermal cycling. Thermal cutting generates surface oxidation and microstructural alterations that compromise the quality of the joint. Cold mechanical beveling eliminates HAZ and oxidation at the edge, resulting in a stable surface ready for welding.
- Titanium: Reacts with oxygen at high temperatures, forming brittle oxides at the edge. Cold beveling eliminates this risk.
For more information on the challenges of machining difficult alloys, read Cold Working of Metals: Challenges and Solutions.
Compliance with welding regulations
Cold machining is required—and often mandatory—by major industry standards.
EN 1090 (mandatory for CE-marked metal structures) requires edge preparation to comply with documented geometric tolerances.
ISO 3834 (fusion welding quality) requires process control that includes qualification of joint preparation.
UNI EN ISO 9692 specifies that machining is the appropriate method for J- and U-bevels, as also reported in the official EN 1090 and ISO 3834 documentation.
The cold-beveled edge meets all these requirements without reworking, additional grinding, or reworking, simplifying quality documentation and reducing process steps.
Choose the right solution for your application
From small-diameter tubes for heat exchangers to large pipelines, to thick plates for boilers and shipbuilding, cold mechanical beveling guarantees geometric precision and zero HAZ, results that are difficult to achieve with thermal processes.
GBC designs and manufactures pipe beveling and plate beveling machines to cover the entire spectrum of industrial needs, with portable solutions for the construction site and automated systems for series production.
To identify the most suitable model based on material, diameter and type of chamfer, contact the GBC technical team: technical support is able to define the optimal configuration for each specific application.