Innovation

In 1934, engineer Henry Lindsay built the Lindsay Bolt Adapter to replace slower, more labour-intensive ways of fixing steel. The Girder Clamp followed in 1935, and the same clamping principle still drives our R&D today. Learn more about our history of innovation here, or continue below for just one recent example.

A custom-made M5 Hollo-Bolt started with a real customer need. Network Rail came to us needing a high-performance expansion bolt that could be installed with access to only one side of a Structural Hollow Section. Our Technical Support and R&D teams took the existing Hollo-Bolt and scaled it down, and within weeks had designed and manufactured prototypes of an M5 countersunk version with a stainless-steel finish. At Martifer's head office in Portugal, the fixing passed a simulated 45-year corrosion test in the lab, exceeding the life expectancy Network Rail had specified.

Innovation also extends to our service and digital tools, for example, The Girder Clamp Configurator and Hollo-Bolt Selector put connection design in your hands directly, size, load, flange, and standard, without waiting on a callback.

Measured installation time, not an estimated saving

An independent fabricator installed the same four-bolt connection two ways, filmed and timed start to finish.

The result:

Traditional drilling & bolting: 18 minutes 05 seconds

Lindapter Girder Clamps: 2 minutes 24 seconds

That's 8 times faster. An 87% cut in installation time, on camera. Watch the drilling comparison.

We ran the same test against site welding: 19 minutes saved and an 88% reduction. Watch the welding comparison. Two methods, two independent tests, the same result, clamping is faster than the alternative, on the clock, not just on paper.

Scale either figure to 1,000 connections and you're not looking at a marginal gain anymore, you're looking at a programme decision.

Cost-effective

Reduce the activities surrounding the connection, not just the connection itself. The more useful engineering comparison is the total installed cost. Every minute in the table above has a labour cost attached to it. 

And the saving doesn't stop at labour:

No mag drill to hire, transport, or power on site

No specialist certification needed to operate a hand tool

No coating repair once a hole's gone through the finish

No hot-work permit or fire watch operative

No rework, position and check before you commit

Installation time saved × applicable labour cost + equipment and site-operation costs avoided = project-specific saving. Reduced labour hours plus equipment you no longer need to hire is the cost case, and it's the same maths behind the time-saving videos above, just expressed in pounds instead of minutes.

Easy to install

Installation simplicity has a direct engineering benefit when connections are being made in variable site conditions.

Every Lindapter installation video shows the same thing: a hand tool, a simple connection, done. No need for welding, additional equipment or specialist PPE beyond what's already standard on site.

Girder Clamps are designed to be installed using standard hand tools, without the need to drill or weld the supporting steelwork. The connection can also be adjusted during installation: the steel section can be moved into the required position before the clamp is finally tightened.

That adjustability is particularly useful where steelwork tolerances, site access or the final position of secondary steel cannot be established with absolute precision before erection. Type AAF's self-adjusting rocking washer takes flange-thickness variation out of the equation entirely, so you're not fighting tolerances on site. For hollow structural sections, the Hollo-Bolt provides the same fundamental installation advantage in a different form: the connection can be installed from one side where conventional through-bolting would require access to both faces of the section. 

And have a look at how safe, fast and simple it is to install a decking fixing compared to the alternative. Clipped into place by hand in a fraction of the time a drilled fixing takes. 

Safer

Compare it to the two methods it replaces. Site welding needs a hot-work permit and, without existing fire protection, a fire watch operative on standby throughout. Site drilling needs a mag drill positioned and powered at every connection, plus swarf and dust control. Lindapter needs a hand tool. The difference is particularly relevant when connections are being installed at height.

For decking specifically, avoiding drilling into concrete avoids the associated exposure to respirable crystalline silica, a hazard that's rightly under growing scrutiny across the industry. The benefit is therefore that specific site hazards can be designed out by changing the connection method.

Sustainable construction

Sustainability isn't just what a product's made from. It's how it's installed, maintained, adapted, and removed.

Our products are 100% recyclable, manufactured primarily from iron, carbon steel, or stainless steel, materials that are inherently recyclable. At the end of their service life, they should go back through appropriate metal recycling facilities, in line with local waste management and disposal regulations. Lindapter also operates an ISO 14001-certified Environmental Management System, in place since 2010, covering areas including natural-resource use, waste management and energy consumption.

Lindapter steelwork clamps are installed without drilling into the steel, preserving the full integrity of the steel section. This facilitates future adaptation, disassembly, and reuse of the structure, supporting sustainable construction and material circularity.

High Performance

Lindapter has gained ETA / CE Mark approval of its Type AF and Type AAF Girder Clamps for use in dynamic loading applications. This extends the range of approved options available to Engineers when designing a connection subject to fatigue in accordance with Eurocode 3. Dynamic loading capacities for these products have been published in Lindapter’s Declaration of Performance documents.

These latest third party approvals are in addition to independent dynamic load testing commissioned by Lindapter for its Hollo-Bolt products.

All independent fatigue resistance tests were performed in accordance with EN 1993-1-9: Design of steel structures - Part 1-9: Fatigue. A number of tests were performed at different load levels from 10,000 to 2.5 million cycles in order to determine suitable detail categories. 

Durability, tested against the conditions you're building for

Corrosion: Products supplied in a hot-dip galvanised coating have a durability of 50+ years in C1/C2 environments and 20+ years in C3.

Fire Rated: Selected products have a Fire Rating of 120 minutes based on the standard fire curve to ISO 834, and 120 minutes to ASTM E-119 for the North American equivalents.

Sub-Zero: Type AAF has been independently tested down to -60 degrees C and the Hexagon Head Hollo-Bolt tested down to -45 degrees C.

Vibration, seismic, and dynamic loading: covered by fatigue testing, cycled to 2.5 million loads under EN 1993-1-9, and independently tested and evaluated by ICC-ES.

Global leader, backed by international approvals & a history you can check

Ninety years of proven expertise, starting with Henry Lindsay in 1934, through connections used in Bailey Bridges and Mulberry Harbours during the Second World War, to becoming Lindapter International in 1981 as the business went global.

ICC-ES: Type AF/AAF and Hollo-Bolt approved under ESR-3976, assessed to AISC 360, AISC 341, ASCE/SEI 7 (Girder Clamps) and AISC 360, AISC 341, AISI S-100 (Hollo-Bolt), including seismic design, per ICC-ES Acceptance Criteria AC469

CE Marking: ETA 20/0917 (Hollo-Bolt), ETA 20/0918 (HSR & Girder Clamps), ETA 20/0919 (Floor Fixings), ETA 20/0920 (Decking Fixings), each with a Declaration of Performance for Eurocode 3 design

UKCA: UK Technical Assessment with Declaration of Conformity, Factory Production Control assessed by a UK Approved Body

ISO 9001:2015: BSI certificate Q 05143, registered since 1986

ISO 14001: certified Environmental Management System since 2010

Additional approvals from Factory Mutual, TÜV Nord, Lloyd's Register and VdS.

Products built in the UK, approved for use worldwide.

Comprehensive technical support, from specification to installation

Free connection detailing from our technical team, built around your actual requirement. Need something outside standard configuration? Our Engineered Solutions team builds bespoke connections.

For standard specification, use the Girder Clamp Configurator and the Hollo-Bolt Selector tools, backed by full CAD, BIM, and technical documentation, Characteristic Resistances, Safe Working Loads, and approval data included.

Lindapter's Engineers support the process from product selection and connection detailing through to on-site installation guidance.