Founded in Sarreguemines, France over 35 years ago, Optimas International Sofrasar™ has developed into one of the world’s leading suppliers of tunnel components.
Optimas International Sofrasar™ supports major tunnel infrastructure schemes with deep sector knowledge, design and engineering capability, technical expertise and fastening systems, drawing on a combined team experience of over 70 years.
The team currently works on more than 30 projects and supplies approximately 500 products each year. This positions Optimas International Sofrasar™ as a key partner for tunnelling programmes. Projects supported range from 3m diameter tunnels through to some of the largest in the world, including the Tuen Mun–Chek Lap Kok tunnel in Hong Kong. Optimas International Sofrasar™ operates across sewer, cable, metro, railway and road tunnel applications.
The main offices of Optimas International Sofrasar™ are located in north-eastern France, where the in-house team holds extensive engineering knowledge. With backgrounds spanning civil engineering, plastics and metal engineering, as well as tunnelling disciplines, the team’s expertise enables Optimas International Sofrasar™ to develop flexible and efficient solutions for a wide variety of tunnelling requirements.
As a result of this broad technical capability, the team designs and delivers bespoke products tailored to specific tunnel applications. This enhances adaptability when addressing project challenges and supports more efficient problem-solving.
This is demonstrated when Optimas International Sofrasar™ streamlined the construction requirements of a sewage tunnel using highly specialised fastening solutions, helping to accelerate delivery timelines and reduce overall costs. The team engineered and manufactured three custom components that improved installation efficiency, while eliminating ancillary elements such as sockets for concrete anchoring. Each fastener was developed and validated using Optimas International’s in-house testing laboratories, ensuring full suitability for the application.
In addition to its European base, Optimas International Sofrasar™ is supported by local tunnel representatives worldwide, enabling it to meet project needs across Asia Pacific and other international regions. This global capability allows Optimas International Sofrasar™ to support tunnelling schemes in more than 25 countries.
Sustainability is an increasingly important priority across all industries, including tunnelling. The guiding rods supplied are manufactured from 100% recyclable materials, helping Optimas International Sofrasar™ and its project partners reduce environmental impact. In addition, 95% of tunnel products are manufactured in France.
Since its inception in 1989, Optimas International Sofrasar™ has supported more than 600 tunnel projects. Over the past 20 years alone, more than 2,000km of tunnel infrastructure has been supplied.
The product range from Optimas International Sofrasar™ spans multiple systems and categories, including dowel systems, bolting systems, shear cones, guiding rods, grouting and lifting systems, and more. Further details on key product groups are outlined below.
Bolting Systems
Used for assembling concrete segments, rail fixings and conveyor systems, the bolting systems supplied by Optimas International Sofrasar™ can withstand tensile loads from 70 to 400kN. Metallic inserts are manufactured in stainless steel, typically 316L or other grades selected through our engineering and design service. A variety of bolt specifications are available, including ASTM A325 and 10.9 grades, with zinc-plated or hot-dip galvanised finishes also offered.
Dowel Systems
Segment ring fixation using thermoplastic dowels enables fast, secure installation within tight tolerances, while maintaining ring stability underground movement or grout injection pressure.
Centring Systems and Shear Dowels
Centring systems and shear dowels help simplify and speed up the installation of concrete segments, while offering precise control of shear forces up to 500kN. Through the design expertise within Optimas International Sofrasar™ these systems are available in multiple dimensions and thermoplastic grades to achieve the most suitable deflection performance for each application.
Grout-Lift Sockets
A comprehensive range of grout and lift sockets provides watertight sealing via screw caps rated up to 40 bar pressure, alongside pull-out resistance of up to 400kN.
Guiding Rods and Packers
These straightforward and cost-efficient components control alignment between concrete segments, delivering reliable shear resistance while maintaining tight tolerances and reducing slip risk.
Precast Accessories and Security Systems
The portfolio includes a wide range of plastic and metallic inserts for electrical installations, fire protection systems and RFID-based traceability solutions.
How We Can Support Your Tunnel Projects
Optimas International Sofrasar™ provides a comprehensive range of services and products designed to deliver fastening solutions for tunnelling applications.
From engineering and design support through to responsive logistics, quality assurance, validation and testing, Optimas International Sofrasar™ offers end-to-end project support across all stages.
Contact one of our technical consultants to discuss how we can assist with your upcoming tunnel projects and next steps.
