Chesterfield Special Cylinders (CSC) is already realising significant gains following its investment in a DN Solutions Puma 3100LSY multi-tasking lathe from Mills CNC. Increased productivity, improved process efficiency, reduced operating costs and consistently high part accuracy have all been delivered across the board.
Mills CNC, the exclusive distributor of DN Solutions and Zayer machine tools in the UK and Ireland, recently supplied CSC – a market-leading designer and manufacturer of high-pressure gas containment solutions for safety-critical applications – with the new box guideway multi-tasking lathe.
Installed in February 2026 within a dedicated ‘large product’ machining zone at CSC’s 100,000ft² Sheffield facility, the 10" chuck / 102mm bar capacity Puma 3100LSY is equipped with a sub-spindle, Y-axis and driven tooling. Notably, it is the first machine tool the company has purchased from Mills CNC in its 125-year history.
Since installation, the machine has been deployed to machine relatively small industrial cylinders for aerospace and defence applications, while also being trialled on a range of adaptor components with varying geometries.
Cylinder manufacturingCSC manufactures industrial gas cylinders for a growing domestic and international customer base. These products are available in sizes up to 12.5m in length, with capacities reaching 3000L and operating pressures of up to 1000 bar.
The cylinders now being machined on the Puma 3100LSY are smaller in scale and are produced from mild or alloy steel tubes. After cutting to size, they undergo in-house hot forming and forging operations before final machining.
A key machining process involves removing mill scale – a hard bluish-black oxide layer formed during hot working. Its removal is critical, as its presence can compromise finishing processes such as painting or protective coating adhesion.
This is a demanding operation requiring appropriate tooling, such as negative rake carbide inserts, alongside a rigid and stable machine tool platform – a requirement effectively met by the Puma 3100LSY.
Adaptor manufacturingIn addition to cylinder work, the Puma 3100LSY is used to produce a range of adaptor components, including high-pressure fittings and flanges.
These parts often feature intricate geometries and are typically produced in small batches from solid steel billets. By leveraging the machine’s multi-tasking capabilities, CSC can complete these components in a single set-up, improving accuracy while reducing handling and lead times.
Identifying the need for investment
CSC has long maintained a commitment to continuous improvement, regularly investing in people, equipment and processes. In 2025, the company undertook a comprehensive audit of its turning operations to identify bottlenecks and inefficiencies impacting productivity and delivery performance.
The audit highlighted a significant issue with an existing lathe, which had effectively been removed from active production.
“The lathe in question had been earmarked for machining our small cylinder products and adaptors, but it just wasn’t up to the task,” Adam Mellor, CSC’s Production Engineer, explains. “The machine’s limited capabilities, combined with a lack of skilled operators on site, had resulted in us subcontracting our small cylinder and adaptor work out to third party suppliers.”
While subcontracting provided a short-term solution, it introduced cost and control challenges.
“From both a cost and control perspective, we made the decision to bring this work back in house. To achieve this, we decided to invest a new multi-tasking lathe,” Mr Mellor adds.
Defining the right solutionAlthough the Puma 3100LSY was installed in early 2026, the procurement process began months earlier. CSC’s engineering team developed a detailed pre-purchase specification outlining essential machine requirements.
“We knew that we needed a compact lathe with proven multi-tasking capabilities which would enable us to accommodate and machine our small cylinder range and adaptor parts, quickly, and in one go,” Jason Langton, CSC’s project manager, explains. “We also made the decision, from an operator knowledge and familiarity perspective, to opt for a lathe with a Fanuc control as this was our preferred CNC control platform that would enable seamless program sharing across our machines.”
With a clear specification in place, CSC approached a select group of suppliers, including Mills CNC.
“Although we hadn’t previously purchased a machine tool from Mills CNC, our research revealed that the company was well respected and highly regarded,” Mr Mellor notes.
Mr Langton added: “We were impressed with the depth and breadth of Mills’ machine tool range, and with the pre and after-sales services and support the company provides to its customers.”
Following detailed discussions covering technical capabilities, cutting performance, cost and delivery, CSC selected the Fanuc-controlled Puma 3100LSY. The order was placed in late 2025, with installation, commissioning and training completed in February and March 2026.
Machine configuration and capabilityThe Puma 3100LSY was delivered ready for immediate production and equipped with several productivity-enhancing features, including an auto tool setter, LNS mist extraction system and BobCAD-CAM software.
To enhance versatility and future-proof the investment, the machine was also prepared for integration with a programmable steady rest, enabling the machining of longer components when required.
Delivering measurable benefitsIn a relatively short period, the Puma 3100LSY has made a significant impact on CSC’s operations. The company has successfully brought previously subcontracted work back in-house, reducing costs and regaining control over production.
At the same time, machining efficiency, throughput and part quality have all improved, reinforcing the value of the investment and strengthening CSC’s manufacturing capability for the future.