Subcontractor Stag currently utilises only half of its single- and multi-spindle auto capacity, as orders for large batches needed to justify their use are becoming increasingly scarce.
Subcontractor, Stourbridge Turning and Grinding (Stag), currently utilises only half of its single- and multi-spindle auto capacity, as orders for large batches needed to justify their use are becoming increasingly scarce, and those that remain tend to go overseas. Since 2001, CNC mill-turning machines, in particular multi-axis sliding-headstock lathes from Star Micronics GB, have been fulfilling contracts for smaller volumes much more cost-effectively. 'They can be set up quickly and are able to produce parts in one visit to the machine, eliminating manual second operations,' explained Stag director, Giles Pargeter.

'As a result, in four years we have reduced our shop floor staff from 23 to 14, which has resulted in significant savings and made us much more competitive.' Between August 2002 and December 2005, Stag invested in four sliding-head bar automatics of 32 mm capacity, one 20 mm machine and a 16 mm model, all from Star.

'After the first lathe was installed, I could not believe how much more profitable manufacture of components became compared with machining them on our cam auto's,' Mr Pargeter enthused.

'It opened up new possibilities for producing higher added-value components that we could not have entertained before.

Nearly all parts undergo prismatic machining operations using live tooling and are machined on the reverse end using the sub spindle.

'Whereas we were selling parts for a few pence at low margins, especially if they needed second operations, suddenly we were turning out complex components in one hit costing several pounds each and making good margins.' Unless a new component is obviously a sliding-head job, Mr Pargeter generally sets it up on a fixed-head lathe if the order is for a small quantity.

However, he estimates that a five-minute fixed-head cycle can typically be carried out on a sliding-head lathe in three minutes, owing to its faster axis travels and shorter tool movements.

He therefore sets up repeat jobs and longer runs on one of his Stars, provided that the component is under 32 mm diameter, as it almost always fulfills the contract more economically and can achieve tighter tolerances as well.

In this connection, he mentioned a square section drive shaft for an engine fuel pump that he machines on a Star SR-20RII to a total tolerance of 15 microns.

Despite the large batch sizes, the customer does not want to put this work overseas, as experience is needed when turning to leave an allowance for growth during subsequent heat treatment and finish grinding.

The manufacturer does not want to risk incorrect shafts from China or India delaying deliveries of its fuel pumps, whereas the supply is much more controllable if it is UK-based.

Many subcontract company owners and directors fear that by the time they retire, foreign competitors will have secured the work that remains in the UK, even the manufacture of highly complex and safety critical components, as the skill level and experience of overseas machinists improve further.

Mr Pargeter takes a more optimistic view of the future of UK subcontracting, however, noting that as components become ever more complex, often requiring design input by the company tasked with machining them, this favours domestic suppliers.

He also predicts that machine tools will become progressively faster and more capable, lessening the advantage of manufacturers in low wage economies.

In ten years' time, the level of wages in those countries will have increased as their citizens demand a higher standard of living.

The combined effect will be to markedly reduce the differential between prices quoted by UK and overseas subcontractors.

Stag is clearly planning its future based on this premise.

It invested £2 million during 2004 on new plant and larger premises more suitable to the smooth flow of production through to delivery of high precision components.

Three of the new Star sliders were delivered directly to the new factory, which runs around the clock, lights-out from 5.00 pm through to 8.00 am, six days a week.

Around 45 per cent of business is in the supply of hydraulic valve components for off-road vehicles, with the remainder spread across a wide range of industries including automotive, agriculture and construction.

Mr Pargeter plans to continue investing and growing the business.

He says that he finds it difficult to break into new customers these days, as most OEMs and first-tier manufacturers are reducing their supplier base and asking the best subcontractors to increase the work that they do.

So he is actively targeting his existing customers to build turnover, and with some success, having increased tenfold the monthly turnover with one manufacturer.