Bucking the trend during the prolonged downturn in the oil and gas industry, Stonehouse-based Chappell Engineering (www.chappellengineering.com) has just had the most successful four years of its 45-year history after moving to a new facility; since then, it has invested over £5 million in new machines and equipment.

The machines include five XYZ machining centres and turning centres, two Doosan Puma turning centres and nine Mazak machines.

The latter comprise five MY-series turning centres, two Integrex i400S sub-spindle multi-tasking machines, a Nexus 510 machining centre and an i800 Vari-Axis simultaneous five-axis machining centre — the first of this machine type to be installed in the UK.

When considering the i800, Chappell Engineering was looking for an extremely robust, precise and flexible machine that offered a high level of machining performance when working with difficult-to-cut oil and gas materials.

The Mazak engineering team and Chappell Engineering agreed that the machine should be supplied with a CAT50 dual-contact spindle configuration.

This requirement subsequently saw the specification of BIG Kaiser face-and-taper-
contact tool-holders from Tamworth-based Industrial Tooling Corporation (www.itc-ltd.co.uk).

Working with quantities ranging from one-offs to batches of more than 500, 14-employee Chappell Engineering machines a variety of materials associated with the oil and gas industry; these include aluminium-bronze, 316 and 410 stainless steel, 625 and 718 Inconel and super duplex steels.

The company says its success derives from using ‘flexible’ machine tools that are capable of one-hit machining — and a ‘get it right first time’ approach.

High-value parts

Production manager Frank Phillips says: “Our work is all about high-precision high-value parts; and while we achieve cost-effective machining times by using extremely capable machine tools, the critical factors for us are precision, rigidity and getting tight-tolerance jobs right.

For example, a typical billet could cost £1,000, and we often get parts nickel-plated at £1,000 per part, so material costs alone can be more than £2,000 before we start machining; and with finished parts being worth as much as £10,000, investing in the best machine tools and tooling is essential for the future of our business — hence specifying the CAT50 dual-contact spindle for the i800 Vari-Axis and a complete tooling solution from ITC.


“We wanted to maximise the capabilities of this Mazak machine; and when it came to sourcing tool-holders with face-and-taper contact, we felt that the BIG Kaiser range from ITC was the solution that would best meet our needs. We subsequently ‘tooled’ all 40 positions on the new i800 Mazak with ‘back ends’ from ITC.

The company recommended a series of BIG Kaiser hydraulic tool-holders, heavy-duty tool-holders and ER collets. Furthermore, because the i800 has a trunnion table that can be used for turning diameters up to 1m, ITC’s engineer Neil Vine also supplied heavy-duty CAT50 turning tool-holders and turning tools.

In the six months since installing the Mazak i800, the BIG Kaiser dual-contact tool-holders have demonstrated astounding levels of rigidity.

“This rigidity is not only key to the high levels of precision we are achieving but is also providing improvements in tool life, surface finish and productivity — to such an extent that we have set about implementing BIG Kaiser tool-holders throughout our machine shop.”

Difficult access

The Mazak i800 is now primarily tooled with ITC-supplied cutting tools. These include Widia face mills (63 and 80mm in diameter), Widia end mills (in diameters from 6 to 20mm), and a variety of Widia indexable-insert turning tools. ITC’s Mr Vine also supplied BIG Kaiser BCV50 Mega 20N long-series tool-holders for reaching into deep bores and for milling and drilling difficult-to-access features.

A recent example where a long-reach capability was necessary was when machining an 800mm-long rectangular gate valve component for the oil and gas industry.

This featured a 250mm-diameter turned feature at the centre of the valve that required side drilling and threading at a depth of 275mm. To reach this depth and provide sufficient clearance of the work-holding fixtures, the drills and subsequent thread-milling cutters were used with a 300mm-long BCV50 Mega 20N long-series tool-holder.

Chappell Engineering has now acquired a number of these long-series tool-holders for machining difficult-to-access features on large components. One project — machining super-duplex ‘sub risers’ for use at the base of an oil well — required a Mazak Integrex i400 to undertake cross-drilling and the milling of a flat at the base of a 274mm-deep bore; with an actual drilling depth of 110mm, the effective overall hole depth was 384mm.

A 300mm-long BIG Kaiser hydraulic chuck with a C6 Capto back end was used with a 150mm long drill; moreover, this tool assembly maintained a run-out precision of less than 5µm.

In conclusion, Mr Phillips said: “This sub riser starts as a large billet that requires nickel plating in the bore, which takes the cost of the part beyond £2,000 before any machining takes place. To use anything other than the very best tool-holders and tools would be ridiculous.

“Very few companies have invested in robust and precise machine tools, tool-holding and tooling to the extent that we have. This level of investment enables us to take on work that other sub-contractors shy away from.

“Investing in the very best technology also allowed us to continue being very successful through what has been a difficult period for the oil and gas industry.”