LONGER PRODUCTION RUNS OF TURNED PARTS DICTATE MOVE TO SLIDING-HEAD TURNING

SFC (Europe) Ltd is a market leader for the manufacture, stocking and supply of safety-critical and high-performance studbolts, bolts and nuts in ASTM and ASME grades for onshore, offshore and subsea applications. They are mainly destined for global energy customers, but are also used in the automotive, valve, heat exchanger and pumps sectors. The Wolverhampton company has enjoyed impressive growth, from a turnover of ￡1 million when it was formed in 2013 to ￡15 million in 2024.

In the early days, the company served mainly the oil and gas, petrochemical, valve and renewable energy sectors, which involved turning batch quantities of anything from five to 500 parts, with the occasional run of 1,500. Then in 2018, other industries started to show interest in the products and today the original markets account for only around half of the manufacturer's turnover. Some of the more recent customers ask for similar, small to medium quantities, but frequently they request 50,000-off, forcing SFC (Europe) to change the way it viewed its turning and milling equipment.

Operations director Mark Edmonds said, "In the early days we bought in fasteners for stock and sold them worldwide, but within six months we had gained ISO 9001 and started manufacturing product, either to customer specification or international standards.

"Our machine tool count was boosted in 2016 through the acquisition of another fastener producer. The capacity was sufficient for the quantities we were producing at the time, but a couple of years later the larger quantities being ordered by customers necessitated a rethink."

Part of the deliberations was shaped by the metals that need to be machined. As well as carbon steel, they include stainless and superalloyed steels, and nickel and titanium alloys. One nickel-copper alloy, Monel K500, is particularly difficult to machine due to its ductility and abrasiveness. Any new turn-milling centre had to be robust enough to process these materials. It also had to be versatile and quick to set up, as urgent short runs were frequently ordered for next-day delivery while long-running jobs were in progress.

Since 2019, Mr Edmonds and his colleagues had been considering sliding-head bar turning owing to its suitability for producing large quantities of components, including unattended overnight. Covid delayed things somewhat but by mid-2022 SFC (Europe) was ready to make its first investment in new turning centres. It was, however, a pair of fixed-head lathes that was bought, as production staff in the Wolverhampton factory was unfamiliar with operating sliding-head equipment and management wanted modern, productive lathes that would come on-stream quickly.

Two identical 7-axis Miyano BNA42DHY twin-spindle, twin-turret, bar-fed lathes were duly installed, the first machines that the manufacturer had sourced from Citizen Machinery UK. The supplier was chosen after subcontractors within the fastener industry had been consulted, as well as Google of course, plus Citizen at one of its open houses. Demonstrations at the Brierley Hill technical centre, where faster than expected, one-hit cycles were shown to successfully replace three or four separate operations, clinched the deal.

A couple of years later, SFC (Europe) was ready to revert to the idea of introducing sliding-head, bar-fed lathes. The Miyanos had performed so reliably in terms of uptime and accuracy that Mr Edmonds looked no further than Citizen for the supply of two Cincom L32-VIIILFV turn-mill centres. Delivered and commissioned in April 2024, they mainly fulfil orders for higher volumes of parts. As traceability is often important, the ability to engrave them in-cycle on the fast, nimble machines saves a separate operation and contributes to maximising production output.?

The nominally 32 mm bar capacity lathes are able to machine components from up to 38 mm bar with the guide bush removed, which has the added advantage of saving material due to shorter remnant lengths. Accordingly, one L32 is permanently set up without the guide bush for producing parts up to about 2.5 times diameter, while the other has the guide bush in place for turning longer components.

Mr Edmonds concluded, "Everyone from our founder and chairman Allan Stennett to the machine tool operators on the shop floor are committed to acquiring and using the best production equipment possible. Continued purchase of machines like the Miyano and Cincom lathes will undoubtedly underpin our continued growth for years to come."