African Fusion visits the Roodepoort facilities of Stainless Precision Engineering (SPE) and talks to Reginald Diedericks, the responsible welding coordinator and technical quality manager, about the company’s ISO 3834 quality accreditation and its EN/ISO 15085 and railway aspirations.
Stainless Precision Engineering (SPE) is a privately owned company founded in 1989 as a jobbing shop that relies on state-of-the-art machinery to produce high-quality sheet metal products and components. “We operate a cluster-style management system, with the factory headed by production controllers, overseen by our production director and quality manager,” begins Diedericks. “The secret of our success is that each cluster is accountable for the goods it produces and their quality,” he adds.
“From a quality and inspection perspective, we believe it is important to control quality at source. Before beginning a run on the laser cutter, for example, the operator first completes a test plate cut. He is then responsible for measuring, checking and signing off the test part, based on very specific criteria presented to him on the machines SCADA. Only once the operator has completed the on-screen sign off process, will the machine allow the remaining identical parts to be produced,” he explains.
SPE’s 6 500 m2 factory floor is dominated by Amada CNC machines. For laser cutting, the company has four FO-3 015 4.0 kW lasers with 3×1.5 m cutting beds capable of cutting thicknesses of up to 20 mm in mild steel, 12 mm in stainless steel and 10 mm in aluminium. In addition, the company has an RI (rotary index) version of the Amada FO-3 015 laser that can also cut or profile 6.0 m lengths of round pipe up to 220 mm in diameter; square tube from 19 to 150 mm; angle sections of 90×90 mm; and 150 mm channel sections.
“Laser cutting machines, coupled with the CNC process, enable us to rapidly produce complex and highly accurate flat profiled parts that are easily replicated,” Diedericks points out.
SPE’s modular punching machines offer flexible manufacturing runs without the need for expensive dies and stamping presses – and high volumes are not required to justify the use of this equipment. A 55 station Vipros 255 20-ton Turret punch is available, as well as two 30-ton 49-station Turret punch presses, one of which is coupled to a 4.0 kW laser combination.
SPE offers substantial tooling capabilities for bending stainless steel, mild steel and aluminium in almost every combination. The most impressive of the bending brakes is an AMADA Astro robotic bending system with a 130 t capacity along a 3 000 mm length. The system’s robot picks up a part, measures it and then transfers it to a manipulator on the bending brake itself. The part can then be repositioned as many time as necessary to compete the bending processes, before being transferred out of the cell. Another eight CNC press brakes are in use with up to 7-Axis control, 35 to 200 t capacities and 4 280 mm lengths.
Welding and fabrication
Diedericks, the responsible welding coordinator for SPE’s jobbing shop in Roodepoort, Gauteng, is an artisan boilermaker with a Red Seal certificate and an SAIW Level 1 Inspection qualification. Along with deputy welding coordinator, Gavin Armstrong and a dedicated welding inspector, his team manages the day-to-day quality on the assembly side of SPE’s offering.
“Our welders do their own assembly, which is not quite as complex as boilermaking, and we now have 30 full-time welders who have all been trained in-house and qualified for the welding procedures we use. Every weld now has a welding procedure qualification developed according to ISO 9606-1. We then allocate welders to assembly work and qualify each one for the welds involved – to ISO 15614-1 for carbon and stainless steel and 15614-2 for aluminium,” Diedericks tells African Fusion.
“I have personally employed 17 new welders over the past 18 months to cater for the growth in the business. We look for people who have a practical welding background and we initially test them to see if they have the hand for welding. Then we train and qualify them according to the actual welding work they will be performing,” he says, adding, “We apply the same approach to the grinding and polishing teams, establishing procedures and then training them to do what needs to be done.”
In keeping with its belief in state-of-the-art machine tools, welding assembly is supported by three Fanuc robotic welding systems. The largest is a two-robot cell that includes a 4.0 t manipulator and two multi-axes turntables. A second Fanuc robot is employed as a sub-component assembly station. Both systems use Lincoln welding equipment and are supported by Pretoria-based Robotic Innovations.
“The robot system is used extensively for our ongoing parking systems’ work. The two-robot cell welds the fingers that rise up from the ground at the boom gates to prevent non-payment. The turntable allows the whole part to be rotated for better access to all of the welding required. Boom gates and parking system consoles have long been our flagship capability and we manufacture these for a number of different OEMs,” says Diedericks.
“On the manual side, we use mostly the MIG/MAG welding process with some TIG welding. We also have five spot welding machines and a stud gun,” he adds.
Returning to welding quality management issues, Diedericks says the quality at source approach runs through every aspect of component manufacture. “On the welding side, we do a before, during and after inspection, with our welding inspector taking primary responsibility. Then, after grinding, we apply a visual inspection and sign-off stage to 100% of the assemblies.
Since very early in its inception, SPE has been ISO 9001-certified, but since Diedericks’ arrival, ISO 3834 certification has been implemented to further enhance the quality and creditability of the company on the welding side.
“Our ISO 3834 welding quality system was built from the ground up, with procedure development and training at the root of implementation. It was a mindset change for the fabrication team on the shop floor, to first look for the procedures that applied to the job and then to routinely apply them. On the other hand, welders had to get used to not doing any work that they were not yet qualified for.
“Our welders were willing to learn, though, and they applied the new system with enthusiasm. The whole team has gone out of its way to make ISO 3834 work for us, to improve weld quality and production performance,” Diedericks notes.
“Quality gives us a competitive advantage: We now offer excellent quality on the welding side and this is appreciated by management and customers, resulting in new contracts and in significant growth. So much so that we are having to extend the workshop space to accommodate the additional work,” he adds.
Due to the significant increase in railway contracts being awarded to SPE, the company is also gearing up for ISO 15085-accreditation for the manufacture of railway components and structures. “We are currently involved with Bombardier, fabricating high voltage cubicles and traction converter cabinets for one of the South African railway rejuvenation projects. We are also making the frames for 2.0 m locomotive radiators for a railway sub-contractor and, in aluminium, we have started to fabricate the driver control panels for railway climate control solutions,” Diedericks reveals.
“We are aiming to become a railway specialist, hence the need for ISO 15085. We expect to be audited during August and we hope to be CL2-accredited before the end of this year,” he tells African Fusion.
“SPE is constantly striving for product excellence by keeping up-to-date with the latest technologies and trends in the sheet metal Industry. We guarantee excellent service to all our clients with timeously delivered, quality-inspected goods that are certified to international quality standards,” he concludes.