VTL vs VTC vs Vertical Borer

    The terminology around vertical turning machines can be confusing, with several terms used to describe similar — but not identical — machines. Understanding the differences helps you specify the right equipment for your application and communicate clearly with suppliers, engineers, and operators.

    Vertical Turning Lathe (VTL)

    A Vertical Turning Lathe is a machine tool where the workpiece rotates on a horizontal table and the cutting tool is applied from above. The term “lathe” reflects the machine’s fundamental operation — it is a lathe turned on its end. VTLs typically have two axes: the vertical ram (Z) and the horizontal tool head traverse (X). Modern VTLs are CNC-controlled, offering programmable speeds, feeds, and positioning.

    VTLs are the workhorses of heavy turning operations — the machines you turn to when the workpiece is too large, too heavy, or too awkward for a horizontal lathe. They are found in foundries, forge shops, power generation maintenance facilities, and heavy engineering workshops worldwide.

    Vertical Turning Centre (VTC)

    A Vertical Turning Centre is a more advanced configuration that may include additional axes, automatic tool changers, live tooling, and integrated measurement systems. The term “centre” implies a more complete machining capability — not just turning but potentially milling, drilling, and inspection in a single setup. VTCs are common in high-precision sectors like aero engine manufacturing, where multiple operations on a single component must be completed without refixturing.

    The distinction between a VTL and a VTC is not always clear-cut — some manufacturers use the terms interchangeably, and the configuration that matters is the specific axis count, tooling capability, and feature set of the machine in question. When specifying a machine, it is best to define the required capabilities rather than relying on terminology alone.

    Vertical Borer

    A vertical borer is the traditional term for a vertical turning machine, often associated with older, manually operated machines. Webster & Bennett vertical borers are classic examples — robust, large-capacity machines originally designed for manual operation. Many of these have since been retrofitted with CNC controls, blurring the line between “borer” and “lathe.”

    In practice, the terms are often used interchangeably, and the specification that matters is the machine’s capacity, control system, and axis configuration — not the label on the nameplate. What all these machines share is the fundamental vertical orientation: a horizontal table carrying the workpiece, with tooling applied from above.

    The CNC Machines We Designed and Built

    Between 1993 and 2010 we designed and built a range of Webster & Bennett CNC vertical turning centres. We no longer build them new, but we support, service and refurbish them, and sometimes have them available used.

    Millennium

    The Millennium, launched in 1996, is our flagship 3-axis vertical turning centre. With a live spindle and C axis, it combines precision turning with contour and thread milling, drilling, grinding and elliptical turning, with capacities from 1000mm to 2200mm diameter. World-leading companies bought it for defence and aerospace work.

    Evolution

    The Evolution, from 2004, is built on the over-engineered structure of the Webster & Bennett 36, 48 and 72 manual machines. The result is a 12kW, 2-axis CNC machine for turning, grinding and PCD drilling, with turning diameters up to 2100mm.

    Revelation

    The Revelation, from 2006, is a range of super heavy 3-axis vertical turning centres for turning, grinding and contour milling, with capacities up to 5000mm diameter. It brought innovative tooling developments and robot loading.

    Aeroturn

    The Aeroturn, launched in 2009, was the last range we built new. It was designed as a faster, lighter-duty machine than the Millennium, and even with linear guideways it proved very powerful for precision turning, milling and grinding. A twin-ram version added a swivelling grinding spindle.

    Every machine is different. Talk to Iain about the specification, condition and support options for a particular machine.

    Manual to CNC Conversion

    Many workshops have serviceable manual vertical borers that are mechanically sound but limited by their control systems. The machines can still produce good work, but the manual controls are slow, inconsistent for batch production, and increasingly difficult to support as spare parts for old control systems become scarce.

    Converting these machines to CNC is one of the most cost-effective ways to gain modern machining capability. Our CNC retrofit programme — known as ManuPlus — transforms manual vertical borers into fully programmable CNC vertical turning lathes. The process retains the machine’s existing mechanical structure (including table, column, ram, and slideways) and replaces the control system, drives, and electrical infrastructure with modern components.

    Benefits of manual-to-CNC conversion include:

    • Programmable spindle speed and feed rates — select the optimal parameters for each operation without mechanical gear changes
    • Automatic tool positioning with stored part programmes — recall a setup in seconds rather than spending time on manual positioning
    • Consistent repeatability for batch production — every part comes out the same, without operator-dependent variation
    • Improved accuracy through modern encoders and servo drives — precise positioning with feedback, not manual handwheel positioning
    • PUWER-compliant safety systems — meet current health and safety legislation with modern safety circuits and interlocks
    • Reduced setup time and operator dependency — shorter changeovers, less reliance on the skill of individual operators
    • Conversational programming for simple operations — programs can be created at the machine without needing CAM software

    If you are unsure whether your existing machine is suitable for CNC conversion, we offer a no-obligation assessment. We will inspect the machine, report on its mechanical condition, and advise on the feasibility and cost of retrofitting. Many machines that appear to be candidates for replacement are in fact excellent retrofit candidates — the mechanical structure is sound, and only the control system needs updating.

    Applications: Rings, Casings & Heavy Parts

    CNC vertical turning lathes are the machine of choice for a wide range of components across multiple industries. The vertical orientation makes them particularly well suited to disc-shaped, ring-shaped, and box-shaped components where the diameter exceeds the length.

    Ring and Bearing Components

    Large-diameter rings, bearing races, and slewing rings are natural applications for vertical turning. The horizontal table supports the ring’s weight, whilst the vertical tool head machines the inner and outer diameters, face surfaces, and any grooves or profiles required. For large-diameter rings in particular, a vertical turning lathe is often the only practical option — the swing capacity required would make a horizontal lathe impractically large.

    Casings and Housings

    Turbine casings, pump housings, valve bodies, and gearbox castings are routinely machined on vertical turning lathes. The open table design allows large, irregular castings to be clamped securely, with the vertical tool head accessing bores, faces, and sealing surfaces. The ability to machine multiple features in a single setup improves accuracy and reduces handling time.

    Heavy Rotating Components

    Flywheels, rotors, discs, and other heavy rotating components are well suited to vertical turning. The table’s rotary motion provides the cutting speed, whilst the tool head controls the feed and depth of cut. The vertical orientation means that heavy components do not need to be balanced against gravity in a chuck — they sit on the table and rotate on the table bearing.

    Sector-Specific Applications

    • Defence: Gun breech components, vehicle transmission housings, ordnance parts, and armoured vehicle components requiring robust, reliable machining
    • Nuclear: Pressure vessel flanges, reactor components, shield assemblies, and containment parts requiring full traceability and documentation
    • Oil and gas: Wellhead components, valve bodies, Christmas tree parts, flanges, and pressure-rated fittings requiring precision machining to industry standards
    • Aero engine: Turbine casings, combustor housings, discs, rings, and engine assemblies requiring extreme precision and consistent quality
    • Aerospace: Structural components, landing gear parts, actuator housings, and airframe components with tight tolerance requirements

    Capability Review

    Selecting the right CNC vertical turning lathe requires a clear understanding of your component requirements. The wrong specification can result in a machine that is either undersized for your needs — leading to poor performance and premature wear — or oversized, meaning you have paid for capacity you do not use.

    When you contact VTT-WB, we will work through a capability review with you, covering:

    • Component dimensions: Maximum diameter, height, and weight of typical workpieces
    • Material types: Ferrous, non-ferrous, exotic alloys, and their machining characteristics
    • Tolerance requirements: Typical and critical tolerances that the machine must achieve
    • Production volume: One-off, batch, or continuous production — this affects control system and automation requirements
    • Operations needed: Turning, facing, boring, contouring, and any special operations
    • Tooling requirements: Standard or special tooling, live tooling needs, and tool change frequency
    • Control preferences: Conversational programming, G-code, or CAM-generated programmes — and networking requirements
    • Available space: Floor space, ceiling height, and foundation requirements

    From this review, we can recommend the most appropriate machine — or advise on retrofitting or reconditioning your existing equipment. The goal is to match the machine to the application, not to sell the most expensive option available.

    To arrange a capability review, call Iain Exeter on 07808 789597 or Petr Gabrhelik on 07808 789598, or visit our contact page.

    See also: our vertical boring machines range, reconditioning services, Webster & Bennett heritage, and used vertical lathes in stock.

    More reading: browse all VTT-WB guides, including rebuild or replace? how to decide.