Why Choose SGH for Injection Moulding?
5–650 tonne injection moulding capacity • In-house tool design and toolroom engineering • Class 8 cleanroom assembly capability • High-mix, low-volume manufacturing expertise • Approx. 1,000 SKUs manufactured annually • In-house EDM and CNC toolroom capability
Who we help
From product developers requiring structured Design for Manufacture support to established engineering and procurement teams seeking a stable UK injection moulding partner, SGH provides scalable manufacturing backed by in-house tooling and disciplined quality systems.
For product developers and growing businesses, we translate early-stage concepts into manufacturable components — aligning material choice, tooling strategy and production planning from the outset. Our in-house toolroom and engineering team ensure your design works in steel as well as it does on screen.
For experienced engineering and procurement teams, we operate as a long-term manufacturing partner — delivering quality, consistency and high-mix production control at scale. Many of our client relationships extend over decades, not individual projects.
For more detailed technical guidance, explore our Technical Resource Centre or see our FAQs for specific answers.
Engineering-Led Manufacturing
Explore our Technical Resource Centre for detailed guidance on injection moulding process control, tooling strategy, dimensional stability, validation and sustainability.
Why Us
We Incorporate the Best of the Past and Future
With decades of hands-on manufacturing experience, SGH brings a deep understanding of what works — and why it matters. But we don’t stop there. By combining time-tested techniques with the latest in design tools, automation, and materials, we deliver smarter, more efficient solutions for today’s plastic products. It’s this balance of heritage and innovation that sets SGH apart — helping clients old and new bring their ideas to life with confidence.
See the Services we offer.
47+
Years of Manufacturing
Experience
For over four decades, SGH have been trusted by businesses large and small to deliver reliable, high-quality plastic injection components. That experience means we’ve seen what works, solved complex challenges, and built long-lasting relationships across a wide range of industries. Our team combines deep technical know-how with a practical, problem-solving approach — so whether you’re launching a new product or scaling up production, you’re in capable hands.
See the Industries we work with.
Our Partners
Brands & companies we work with.
SGH are proud to support industry-leading brands like JCB and Rockwell Automation — as well as countless innovative startups and growing businesses across the UK.
Frequently Asked Questions
Injection moulding typically achieves tolerances around ±0.1 mm for many engineering-grade applications, depending on material and tool design. Dimensional stability is controlled through structured DFM review, precision tooling and validation processes.
Explore: Dimensional Control & Tolerances
Yes. SGH operates an in-house toolroom supporting tool manufacture, modification and lifecycle servicing. Approximately 85% of tooling is fulfilled through our internal engineering capability.
Explore: Tool Design & Toolroom Engineering
We support structured tool validation and formal PPAP submissions where required, including dimensional reporting and documented process control.
Explore: Tool Validation & PPAP
Our injection moulding capacity ranges from 5 to 650 tonne clamp force, supporting both small precision components and larger industrial mouldings.
Explore: Injection Moulding Process
Yes. SGH manufactures approximately 1,000 active SKUs annually, operating within a disciplined high-mix environment supported by structured scheduling and tool lifecycle management.
Explore: Low Volume & High Mix Manufacturing
SGH operates a Class 8 cleanroom for controlled assembly and regulated manufacturing environments, supporting medical and technically demanding sectors.
Explore: Cleanroom Assembly & Controlled Environment Manufacturing
what we do for our clients
Client Case Studies
As part of our ongoing support, we work with the JCB UK design team on polymer selection, Design for Manufacture reviews (DFM), and tooling layout. We also run a fully equipped warehouse solution for JCB with regular weekly drops to run along side their JIT / Kanban system thus removing cost and overheads from the JCB group.
We are rated top 20 percentile globally within their continuous supplier assessment.
In a 2025 supplier assessment and audit at SGH’s facilities in Bolton, the assessors from Poland stated ‘We needed to come and visit SGH in person; we have gone through our records and there are no quality defects or claims on your record. Not figuratively, but literally. You are our best performing supplier” SGH has been invited to Poland to discuss expanding the SKU line as a result.
We are very proud of audits and relationships like this. It’s not a one-off, we consistently score as a top supplier in the national and multi-national businesses we work with over multi-year or decade relationships.
During the difficult times witnessed due to Covid, SGH were able to react quickly setting up dedicated supply cells and moving the facility to a twin shift 5 days a week to support the urgent needs of components for Oxylitre’s manufacturing facility in Manchester, and ensuring the increase demand was met without delays.
15 years on, they’ve shown the Dragons don’t always get it right with their innovative thermal skirting board revolutionising home heating, and SGH are proud to be a key supplier of plastic injection moulding in the ThermaSkirt production.
accreditations and associations
Quality Systems & Accreditation
