Roberto Priolo talks to Metal Spinners, a North East-based company that manufactures components and sub-assemblies through unique and rather unknown processes.
Some believe that metal spinning, shear forming and flow forming are the preserve of a few skilled craftsmen, but in the right hands they are complex manufacturing processes that require engineering technology and expertise.
Metal Spinners, a Newcastle-based supplier of components and sub-assemblies, has been mastering these operations since 1953. The company employs 90 people at two sites and provides solutions for a variety of industries, from oil and gas to defence, from aerospace to architectural projects.
Managing director Brian Batchelor says: “We position ourselves as a manufacturing solutions provider for cylindrical hollow components and ancillary processes, rather than a pure metal spinning company.”
In March 2011 the business was acquired by US-based Standex, which saw in business a drive for high integrity products. Batchelor says: “Standex acquired us because we are a healthy, successful business. There was no headcount reduction, the only change in personnel being the exit of previous owners and managers.”
Soon after the acquisition, a £1m investment in new machinery was made, to purchase a PNC1600, a CNC spinning lathe capable of producing components to 3.2 metres diameter. Metal Spinners also owns two of the largest, multi-purpose, machines in the world, two PNC1800 machines, which allow it to have the flexibility to produce a wide range of components. Development director Paul Pearce said: “There are larger machines in the marketplace, but they are highly specialised and designed to produce one thing only.”
The history and the vision
Over the decades, Metal Spinners built a strong reputation for quality. Pearce said: “Our products started to be at the top end of the range they were supplied into. This drove our own technogical progress, leading us to introduce the first hydraulic operated machine in the UK. In 1965, we introduced the first CNC spinning machine in the country.”
Through organic growth and the acquisition of complementary businesses, Metal Spinners continued to expand. In 1997, it was acquired by Precision Engineering International, which changed the direction of Metal Spinners to focus on critical performance industries and applications.
“Customers want a component that is ready to fit without requiring any further processing”
Brian Batchellor, Managing Director, Metal Spinners
With each changing direction however customer-centricity has remained the key to success. “We don’t have a product range, but a process capability we are offering the market. We have to be focused on our customers, and highly value the contribution coming from our employees,” Batchelor explains.
The most important sector for Metal Spinners is now the medical industry. The company supplies components for MRI scanners, for example, but there are several other sectors it operates in. It supplies customers in industries as diverse as defence, oil and gas, aerospace and power generation, also complementing the capabilities of its sister company, Spincraft, in the United States.
Metal Spinners positions itself as a provider of high value, high integrity sub-assemblies. It can manufacture components from a wide variety of metals, ranging from steel and aluminium to exotic materials. The company can produce components in batches as well as one-off pieces. Pearce explains: “We are not volume manufacturers in the common sense of the term. We generally run batches of 50 at a time or less. But we also work on a lot of unusual items with unique shapes, sometimes engineering prototypes or pieces of ‘street furniture’.”
“We are renowned for our investment in innovation”
Paul Pearce, Development Director, Metal Spinners
A skilled and experienced workforce (the company boasts good levels of employee retention), as well as a constant focus on innovation and investment in new equipment, allow Metal Spinners to provide its customers with components and sub-assemblies that are, many times, ready to fit. “In the markets we are serving, customers want a component that is ready to fit without requiring any further processing,” says Batchelor.
The process explained
Designed to produce rotational, symmetric and hollow components, the metal spinning process involves a spinning lathe. Generally, the work piece starts as a circular blank attached to a spinning mandrel. The outer shape of the mandrel is the inner shape of the component to be manufactured. Pearce explains: “Looking at the basic principle, you load the mandrel onto the spinning lathe and the circular blank in front of the mandrel. The lathe will hold the work piece against the mandrel with the hydraulic tailstock. The mandrel and the work piece will rotate at a speed that depends on the shape and thickness needed. A CNC-controlled spinning roller will then make contact with the work piece and take the metal to its plastic condition, allowing it to flow over the mandrel. In a series of passes, it forms the material blank into the shape you require.”
Shear forming is similar to metal spinning, but it produces the finished shape (typically conical) by working from the thickness of the starting blank, in a single spinning pass, deliberately forming a part thinner than the starting blank. Any areas not shear formed will remain at the starting material thickness. Features can be incorporated into these areas prior to the shear forming operation.
Flow forming is an advanced process for manufacturing seamless, dimensionally precise tubular and other rotationally symmetrical products. It involves applying compression to the outside diameter of a cylindrical preform, attached to a rotating mandrel, flowing the material in both radial and axial directions. The process produces dimensionally accurate net or near net shaped, high-quality cylindrical or shaped tubular products.
To ensure the efficiency of its plants, Metal Spinners uses a bespoke software that helps identify waste and process requirements from a theoretical point of view, on which performance is then based. In addition, it deploys a continuous improvement programme.
Performance is measured against a number of indicators. Batchelor says: “In terms of KPIs, we work around a balanced scorecard approach, regularly reviewing all the business metrics we have, such as sales and order generation, quote activity and quote success, and also profitability by customer and by job. We also look at process capabilities, on-time delivery, production losses, reasons for breakdown and OEE. For process control, we use SPC.”
Metal Spinners is working with its American sister company, Spincraft, to devise a combined strategy for business. This partnership is considered as being very beneficial, as the business focuses on its manufacturing and engineering capabilities for the future.