Welcome to

Stonebridge Electromechanical Engineering (SEMEG)

Transformer Services & Sheet Metal Precision Fabrication

At the heart of SEMEG’s philosophy lies an unwavering commitment to technological advancement and customer satisfaction. Since its inception, SEMEG has continuously evolved to address the growing and changing demands of the electrical power sector. The company’s state-of-the-art manufacturing facilities, advanced sheet metal precision fabrication capabilities, strategic partnerships, and robust research and development activities have cemented its reputation as a trusted supplier not only in South Africa, but also across the continent and beyond. SEMEG specializes in the engineering and production of electrical transformers, switchgear, and a range of complementary power equipment. Leveraging precision sheet metal fabrication alongside its engineering expertise, the company delivers products that meet the highest standards of durability and performance. With a dynamic team of engineers and industry professionals, SEMEG prioritizes safety, efficiency, and sustainability, ensuring that every product leaving its facilities embodies these core values.

History of Stonebridge Electromechanical Engineering

Stonebridge Electromechanical Engineering traces its roots to a movement within the transformer industry around 2010, which created the opportunity to establish a new company. Backed by more than 35 years of experience in the transformer sector, the company entered the market through a partnership with a major mini-substation producer serving the mining industry. By 2012, this partnership concluded, paving the way for the creation of Stonebridge Power Transformers. Building on this foundation, the company expanded in 2015 by incorporating ADD Sheet Metal, evolving into what is today known as Stonebridge Electromechanical Engineering (Pty) Ltd. This milestone combined transformer expertise with sheet metal manufacturing capabilities across diverse industries, including telecommunications, refrigeration, generator enclosures, and solar plant infrastructure. In 2025, the company further enhanced its capabilities by introducing laser cutting services, enabling the production of intricate, high-precision metal products for both industrial and urban applications. Today, Stonebridge Electromechanical Engineering stands as a dynamic and versatile manufacturer, proudly serving multiple sectors with high-quality transformer solutions and precision-engineered sheet metal products.

Comprehensive Solutions for Reliable Power Delivery & Industrial Fabrication

Stonebridge Electromechanical Engineering (SEMEG) stands as a trusted partner in the field of transformer services and precision sheet metal fabrication, delivering a full suite of technical solutions designed to ensure the safe, efficient, and long-lasting performance of electrical infrastructure and also supplying to clients across Southern Africa and beyond. With a foundation built on engineering excellence and a commitment to innovation, SEMEG supports clients across the entire transformer lifecycle – from installation to advanced diagnostics, preventive maintenance, repairs, upgrades, and responsible decommissioning – while also offering high-quality, custom-engineered sheet metal solutions for electrical, mechanical, and industrial applications.

Expertise You Can Rely On

SEMEG’s multidisciplinary team of seasoned engineers, technicians, and fabrication specialists brings industry-leading expertise to every project, whether serving industrial plants, utilities, or specialized infrastructure. Their approach combines technical rigor with deep knowledge of power systems and manufacturing processes, enabling them to deliver precise, durable, and cost-effective solutions.

Why Choose SEMEG?

As power networks become increasingly complex and the demand for sustainable energy solutions grows, the importance of efficient and reliable transformers cannot be overstated. SEMEG is poised to play a pivotal role is shaping the future of electrical infrastructure in Southern Africa and beyond. Through its commitment to lower losses, strict adherence to SANS 780 Ed5.1, and passion for engineering excellence, SEMEG is not merely responding to industry trends-it is actively setting new standards. In conclusion, Stonebridge Electromechanical Engineering (Pty) Ltd (SEMEG) exemplifies the spirit of innovation, quality, and sustainability in the transformer industry. By focusing on lower losses and compliance with the latest editions of critical standards like SANS 780 Ed5.1, SEMEG delivers tangible value to our clients and contributes meaningfully to the advancement of energy efficiency and environmental stewardship in the region.

Proven Experience: Decades of hands-on expertise in the transformer sector across diverse industries.

Tailored Solutions: Customized service agreements that fit the unique requirements of each client, from routine maintenance to full asset management programs.

Cutting-Edge Technology: Adoption of the latest diagnostic tools and digital monitoring systems for proactive maintenance and high system reliability.

Safety & Compliance: Strict adherence to national and international standards for transformer maintenance, safety, and environmental protection.

Commitment to Research and Development

SEMEG maintains a dedicated research and development division focused on continual product improvement. Our team pursues innovations in material science, thermal management, insulation systems, and digital monitoring solutions. Our commitment ensures that SEMEG transformers remain at the cutting edge of efficiency and reliability, ready to meet future challenges in the energy landscape.

Manufacturing Excellence and Capabilities

SEMEG operates a full-scale manufacturing facility in Germiston, South Africa, equipped to produce transformers as well as a diverse range of enclosures, panels, and urban metal products, tailored to meet the specific needs of various sectors. SEMEG manufacturing process leverages the latest automation and quality control technologies to ensure consistently high standards. Rigorous testing is conducted at every stage, using specialized equipment to verify compliance with SANS 780 Ed5.1 and other relevant standards.

Quality Assurance and Compliance

SEMEG’s unwavering focus on quality is reflected in its strict adherence to SANS 780 Ed5.1 as well as ISO 9001 quality management principles. Each transformer is subjected to exhaustive type tests, routine tests, and special tests as specified by international and local standards. The company also maintains an internal audit system and continuous staff training to uphold and enhance quality benchmarks. From raw material selection to final assembly and factory acceptance testing, quality is never compromised.

Service Portfolio

Installation & Commissioning: SEMEG ensures precise planning and execution, including site assessment, heavy equipment transport, assembly, and comprehensive pre-energizing testing for a smooth start-up.

Preventive Maintenance: Regular site inspections, oil analysis, thermal imaging, and electrical testing to detect early signs of wear, prevent failures, and extend service life.

Emergency Repairs: SEMEG’s 24/7 rapid-response teams for urgent breakdowns, from on-site repairs to major overhauls, minimizing downtime.

Refurbishment & Upgrades: Winding rewinds, core repairs, and retrofits with modern monitoring and protection systems to meet evolving operational and regulatory needs.

Advanced Diagnostics: Utilizing dissolved gas analysis, frequency response, and partial discharge detection, SEMEG identifies hidden faults and provides actionable insights for predictive asset management.

Decommissioning & Recycling: SEMEG manages the environmentally responsible disposal and recycling of transformers at end-of-life, ensuring compliance and sustainability.

Sheet Metal Precision Fabrication: State-of-the-art CNC cutting, laser profiling, precision bending, and welding for high-tolerance metal components. Products include transformer enclosures, control panels, brackets, mounting frames, and industrial assemblies, all engineered for durability, compliance, and exact client specifications. Integrated fabrication capabilities enable SEMEG to produce custom parts for its transformer projects, ensuring faster delivery, strict quality control, and seamless fit.

By combining transformer service expertise with advanced sheet metal manufacturing, SEMEG delivers a unique blend of electrical engineering capability and precision fabrication craftsmanship — empowering clients to achieve reliable, efficient, and long-lasting operational performance.

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