Half couplers

Half Couplers for Event Technology – Your Rigging Specialist

Half couplers are the quick, reliable way to fix fixtures, devices and accessories to truss tubes and stage structures. At LTT you get TÜV-tested rigging clamps for tube diameters from 20 to 60 mm, in tensile classes up to 750 kg, and in galvanized, black-coated or stainless steel finishes.

Whether you are hanging a moving head on a Naxpro-Truss main chord, retrofitting a device on site or building a clean exhibition stand, the right half coupler makes every mounting job fast and secure. As a specialist for event technology with over 25 years of experience, LTT supplies you with proven brand hardware for professional use.

Browse the range, match the coupler to your truss tube and put your rig on solid footing.

What Is a Half Coupler? Fundamentals of the Halfcoupler

A half coupler – also called a halfcoupler or half clamp – is a rigging clamp that wraps around roughly one half of a round tube and is tightened with a wing nut or bolt. On the opposite side it carries an M10 device screw or an eye bolt, so you can attach a single fixture, bracket or accessory directly to a truss tube.

The key distinction from a double coupler (full clamp) is simple: a half coupler connects a device to a tube, while a double coupler connects two tubes to each other at a fixed or swivelling angle. A theatre hook is a different animal again – it hangs a load over a tube like a hook, ideal for quick, temporary suspension.

In event technology, half couplers are core rigging hardware. They are used to mount lighting fixtures, speakers, cameras, banners, glass panels and countless other components onto aluminium truss systems. Because a half coupler only grips part of the tube, it is often used in pairs for heavier or longer loads, distributing the working load limit across two clamping points.

Unlike plumbing or agricultural pipe clamps, event-grade half couplers are designed and tested for overhead rigging: they carry defined tensile and shear load ratings and are typically TÜV tested, which makes them suitable for professional stage, club and exhibition applications where safety above people's heads is non-negotiable.

Half Coupler Types and Variants (Standard, Eye Bolt, Glass Panel Holder)

Half couplers come in several models, each tailored to a specific mounting task. Choosing the correct variant keeps your rig clean, safe and efficient.

Standard half coupler

The classic workhorse. It fixes a single device or bracket to a truss tube via an M10 device screw. Available for 20, 32–35, 48–51 and 60 mm tubes, with tensile ratings from 10 kg up to 750 kg depending on width and build.

Half coupler with eye bolt (M10 ring)

This variant replaces the device screw with a welded or bolted M10 ring eye (C15E). It creates a defined suspension point for shackles, safety cables or hoist attachments – ideal for hanging points in rigging.

Half coupler with glass panel holder

Equipped with a plate clamp for panel thicknesses of 6–10 mm or 10–16 mm, this model secures glass or acrylic panels and signage to a truss, typically rated up to 20 kg.

Wide, narrow and heavy-duty versions

Widths of 30 mm and 50 mm and heavier builds increase the working load limit. Narrow versions handle around 200 kg, wide versions up to 500 kg and heavy-duty couplers reach 750 kg tensile load on 48–51 mm and 60 mm tubes.

Side-entry couplers

Side-entry designs let you clip the coupler onto the tube from the side without threading it over the tube end – a real time-saver on pre-built structures. Some come with a conical connector, some without.

Alongside these event-grade clamps, general steel construction knows the universal half coupler with 45° angles, the 4-hole half coupler for wall and post mounting, and the cross-bracket web (Kreuzbügelsteg) – but for stage rigging the load-rated event models above are the correct choice.

Choosing the Right Size: Tube Diameter and Clamping Range (20 / 35 / 50 / 60 mm)

The single most important selection criterion for a half coupler is the tube diameter it clamps onto. Pick a coupler outside its clamping range and it will neither grip safely nor tighten correctly.

The common event-technology clamping ranges are:

• 20 mm – small tubes, e.g. Junior-Truss and Naxpro FD14 chords
• 32–35 mm – slim main-chord tubes
• 48–51 mm – the industry-standard 50 mm truss tube
• 60 mm – heavy-duty tubes and large systems

Widths of 30 mm and 50 mm determine the contact area and thus the load rating.

Half coupler selection by Naxpro-Truss tube diameter

Because LTT manufactures Naxpro-Truss in-house, you can match couplers to the exact chord diameter of each series:

This mapping removes guesswork: identify your truss series, read off the chord diameter, then select the matching clamping range. If you are unsure which tube your existing structure uses, measure the outer diameter of the main chord with a caliper before ordering.

Compatibility with Naxpro-Truss, Junior-Truss and Other Systems

Half couplers are only as good as their fit on your specific truss system. LTT half couplers are engineered around the standard event-technology tube diameters, which makes them compatible with a wide range of systems.

Naxpro-Truss compatibility

As a manufacturer, LTT offers half couplers that fit every Naxpro-Truss series: the 20 mm coupler for the FD14 system, 32–35 mm couplers for FD21–24, 48–51 mm couplers for the 50 mm FD31–44 and HD31–44 chords, and 60 mm couplers for the heavy GS94 series. This end-to-end coverage is a genuine advantage of sourcing clamps and truss from the same specialist.

Junior-Truss and small-tube systems

The compact 20 mm half coupler is designed for Junior-Truss and other small-diameter structures, giving lightweight fixtures a secure home on slim tubes.

Third-party truss systems

Because diameters such as 50 mm and 60 mm are industry standards, LTT half couplers also clamp onto tubes from other well-known truss brands within their rated clamping range. Always confirm the actual outer tube diameter of your system rather than relying on the product name alone.

For the truss itself, explore the wider Naxpro-Truss and aluminium truss range and combine it with matching clamps for a coherent, load-rated setup.

Load Capacity, WLL, Shear Load and TÜV / DGUV Safety

Understanding load ratings is essential when rigging above people. A half coupler carries two very different figures, and confusing them is a common – and dangerous – mistake.

Tensile load vs. shear load

The tensile load (Zugbelastung) acts along the axis of the device screw, pulling straight down when a fixture hangs below the tube. Event half couplers reach up to 10 kg on 20 mm tubes, 75 kg on 32–35 mm tubes, 100 kg on standard 48–51 mm tubes and up to 750 kg on heavy-duty builds.

The shear load (Scherlast) acts sideways across the clamp and is always significantly lower – typically 30 kg for light couplers, 40 kg for narrow versions and up to 100 kg for heavy-duty models. Never load a coupler sideways beyond its shear rating.

Working load limit and safety factors

The working load limit (WLL) is the maximum load the manufacturer permits in normal use, already including a safety factor against the breaking load. Stay within the stated tensile and shear figures at all times.

TÜV and DGUV Vorschrift 17

LTT half couplers are TÜV tested for reliable rigging. For overhead rigging in event technology in Germany, DGUV Vorschrift 17 (formerly BGV C1) governs the suspension of loads above audiences and personnel, requiring rated, inspected and traceable equipment. Choosing TÜV-tested couplers and respecting their WLL is the foundation of compliant, safe stage rigging. When in doubt, use half couplers in pairs and add independent secondary safety cables.

Materials and Finishes: Galvanized, Black Coated and Stainless Steel

Half couplers are made from steel and differ mainly in their surface finish, which determines corrosion protection and appearance. The right choice depends on where and how you rig.

• Galvanized (silver): The all-round standard. Zinc plating protects against corrosion in indoor use and offers the best price-performance ratio for clubs, theatres and touring.
• Black coated: A powder- or paint-coated black finish that disappears against dark truss and dark stage environments – the discreet choice when the audience should see the show, not the hardware.
• Stainless steel (V2A): Rustproof throughout, the premium option for outdoor events, humid venues and salt-laden or corrosive conditions where galvanized parts would eventually degrade.

Which finish for which event?

Many LTT half couplers are produced in Europe and Germany from quality steel, with rounded edges that reduce the risk of injury during handling. For long-term outdoor installations, stainless steel is the safe investment; for everyday indoor rigging, galvanized or black-coated couplers deliver excellent results at a fair price.

Comparison: Half Coupler vs. Double Coupler vs. Theatre Hook

Riggers regularly face the question of which clamp type to reach for. The following comparison makes the decision straightforward by matching each clamp to its intended rigging task.

How to choose

Use a half coupler whenever you attach a single fixture, bracket, banner or accessory to a truss tube – it is the everyday clamp of event rigging. Reach for a double coupler when you need to connect two tubes structurally, for example when scaffolding a custom grid or adding cross-braces. Pick a theatre hook for quick, tool-light suspension where a load simply needs to hang over a tube and be secured with a bolt. For heavier or longer loads on a half coupler, always mount two couplers as a pair to spread the working load limit.

Buying Guide: Half Couplers for Professionals and Beginners

A good half coupler purchase comes down to matching the clamp to your tube, your load and your environment. This buying guide walks you through the technical buying criteria that matter.

Step-by-step buying criteria

1. Measure the tube diameter – 20, 32–35, 48–51 or 60 mm – and choose a coupler whose clamping range covers it exactly.
2. Define the load – separate the vertical tensile load from any sideways shear load, and stay within the WLL. For heavy or long fixtures, plan for a pair of couplers.
3. Choose the finish – galvanized for indoor, black-coated for discreet rigging, stainless steel for outdoor or corrosive conditions.
4. Pick the variant – standard for devices, eye bolt for suspension points, glass panel holder for panels.
5. Check TÜV testing for compliant overhead rigging.

Mounting tips

Large wing nuts allow tool-free tightening, but for load-bearing rigging apply the specified torque with a wrench rather than hand-tightening alone. Beginners should practise pairing couplers on longer loads and inspect the device screw, wing nut and clamp body before every job. Professionals benefit from keeping couplers by clamping range in labelled cases so the correct part is always at hand.

Weight and specifications

Half couplers are light and stackable: typical models weigh between 0.129 kg and 0.7 kg, so a full case of clamps stays easy to transport for touring crews.

Brands and Manufacturers of Half Couplers

The half coupler range at LTT brings together trusted brands and in-house engineering for professional rigging.

• Riggatec – a leading specialist for rigging accessories, offering the broadest half coupler line-up from 10 kg up to 750 kg, in silver, black and stainless steel, all TÜV tested.
• Naxpro-Truss – LTT's own truss brand, so couplers and truss are matched from a single manufacturer for guaranteed fit.
• Junior-Truss – small-tube systems for lightweight rigging, paired with 20 mm couplers.
• Alutruss and Global Truss – established truss brands whose standard tube diameters are compatible with rated half couplers.

With high-quality brand hardware and manufacturing in Germany, LTT gives you clamps you can rely on show after show.

Accessories for Half Couplers and Rigging

A half coupler rarely works alone. The right accessories complete a safe, professional suspension point.

• Shackles – connect eye-bolt couplers to hoists, slings or safety cables at defined hanging points.
• Safety cables (secondary suspension) – independent backups that catch a load if a primary connection fails, a must for overhead rigging.
• Eye bolts and ring nuts – M10 hardware for creating additional attachment points.
• Spare device screws, spring rings, washers and self-locking nuts – keep your couplers serviceable and job-ready.
• Glass panel holders and plate clamps – for mounting panels and signage.

Explore the wider rigging accessories range to combine couplers with the shackles, cables and truss hardware your setup needs.

Care, Maintenance and Safety Inspection of Half Couplers

Half couplers are load-bearing safety equipment, so care and regular inspection are part of responsible rigging practice.

Cleaning and care

Wipe couplers clean of dust and residue after touring, and keep threads free of grit so the device screw and wing nut turn smoothly. A light film of maintenance oil on the threads prevents seizing. Store couplers dry to protect galvanized and coated surfaces.

Safety inspection

Before every job, check each half coupler for cracks, bent lugs, worn threads, deformed clamp bodies and damaged eye bolts. Discard any coupler showing corrosion pitting, thread damage or deformation – never repair a load-bearing clamp. Under DGUV Vorschrift 17, rigging equipment used above people must be inspected regularly and kept in traceable condition. Documenting inspections keeps your gear compliant and your crew safe.

LTT – Your Specialist for Event Technology

As a manufacturer and full-service supplier with over 25 years of experience, LTT is more than a shop – as your reliable partner we combine in-house production in Germany with a deep range of proven brand hardware. Your half couplers ship from Bocholt, Germany, come with the 3-year LTT warranty and travel worldwide through our international dealer network. Enjoy free shipping from €69, with express delivery available when a show can't wait.

Because we build Naxpro-Truss ourselves, we can match every coupler precisely to your truss – the kind of specialist know-how that turns a good rig into a great one. Complete your setup with the Naxpro-Truss and aluminium truss range and the matching rigging accessories, and put your production on a safe, professional footing.

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