Introduktion
In this guide, I’ll break down what a putlog coupler is, how it works, when to use it, and how to source it. Whether you’re a contractor, site engineer, or procurement manager, you’ll leave with a practical, field-tested understanding you can apply on your next scaffold build.
What is Putlog Coupler
A putlog coupler is a single (half) coupler used to connect transom (the short tube that carries the platform boards) to a ledger (the long horizontal tube running parallel to the façade). In traditional bricklayer’s or “putlog” scaffolds, the transom spans from the ledger toward the wall; the putlog coupler clamps that transom to the ledger, stopping any slip or rotation and keeping the platform stable.
What it looks like: compact, lighter than a right-angle (double) coupler, with a single clamp body and bolt. It’s designed for one tube only, not for connecting two tubes at once like a double coupler would.
Bottom line: the putlog coupler is the platform keeper—it keeps the transom (and the boards on top) locked exactly where they should be.
Types of Putlog Couplers
Not all putlog couplers are built the same. The two manufacturing routes you’ll see:
Pressed-steel putlog coupler
Stamped from sheet steel, light and economical. Ideal for light- to medium-duty façade work where volume and speed matter.Drop-forged putlog coupler
Hot-formed from solid steel for higher strength and durability. Favored where equipment is reused often, handled roughly, or rented out.
Key Functions of Putlog Couplers
Secure the transom to the ledger
They stop the transom from creeping under foot traffic and material loads.Provide lateral restraint for the working platform
By fixing transoms where the boards sit, they cut “racking” and reduce bounce.Help maintain load distribution
Consistent transom spacing + positive fixing = fewer hotspots and a platform that feels even and safe.
Putlog Coupler vs Other Couplers
Putlog vs Right-angle (double) coupler
- Putlog: single clamp for ledger–transom fixing; lighter, faster, not intended for primary joints.
Right-angle: double clamp for tube–tube 90° structural connections; higher slip resistance and capacity.
Putlog vs Swivel coupler
Putlog: fixed 90° relationship (ledger–transom), compact.
Swivel: variable angle for bracing and irregular geometry; heavier and more expensive.
When to use what
Use putlog to position and secure platform transoms to the ledger efficiently.
Use right-angle wherever the joint is structural (e.g., ledger-to-standard) and needs maximum slip/rotation resistance.
Use swivel for braces and any non-orthogonal connections.
Safety Standards and Compliance
EN 74 (Europe)
Specifies performance for scaffold tube couplers (strength, slip resistance, corrosion). Many manufacturers label compliance classes for right-angle/swivel; for putlog couplers, verify the maker’s test data and intended use—they’re typically qualified for ledger–transom fixing, not primary joints.OSHA (U.S.)
Requires all connections to maintain the scaffold’s intended capacity and stability. In practice: select the right coupler for the job, torque correctly, and maintain it.AS/NZS 1576 (Australia/New Zealand)
Requires fittings compatible with system design loadings and proper maintenance/inspection routines.
Installation and Good Practice (Quick Field Guide)
Plan spacing
Set transom spacing to your deck supplier’s spec (e.g., 1.2 m or tighter for boards).Seat the transom
Let the transom bear where designed (against the wall in putlog scaffolds, or on designated supports in independent scaffolds).Fit the putlog coupler
Clamp the transom to the ledger on the inside line, align square, and tighten to the maker’s recommended torque.Check the run
Sight the platform line; re-align any outliers before loading.Re-tighten after first load
A quick re-check once boards and toe-boards are down prevents nuisance movement.
FAQs on Putlog Couplers
What size scaffolding tube fits a putlog coupler?
Standard 48.3 mm OD tubes (check your manufacturer’s tolerance range).
How is a putlog coupler different from a double (right-angle) coupler?
A putlog is a single clamp used to fix a transom to a ledger; a double couples two tubes at 90° and is used for primary structural joints.
Are putlog couplers reusable?
Yes—especially forged, galvanized types when maintained and inspected regularly.
What is the typical load capacity of a putlog coupler?
It’s intended as a platform/transom fixing, not a primary load-bearing joint. Always consult the manufacturer’s slip/strength data and your scaffold design.
Can I buy putlog couplers in bulk with OEM/ODM branding?
Yes. Many manufacturers offer logo stamping, color tags, and custom packaging for distributors and rental fleets.
Do putlog couplers require special tools?
No—typically a scaffold spanner/wrench sized to the bolt (e.g., 21 mm or 23 mm).
How often should they be inspected?
At handover, weekly (or as locally required), after adverse weather, and after impact or overloading.
Are putlog couplers suitable for outdoor use?
Yes—choose varmförzinkad for the best corrosion resistance and keep up with cleaning and storage.
Can they be used in high-rise projects?
Yes—wherever your design calls for ledger–transom fixing on façade/access scaffolds. Follow the engineer’s layout and spacing.
What should I do with damaged couplers?
Quarantine and replace immediately. Don’t attempt to “straighten” or reuse cracked or stripped fittings.
Slutsats
The putlog coupler may be small, but it punches above its weight. By positively fixing transoms to ledgers, it turns a line of tubes and boards into a platform your crew can trust. Choose the right build (forged vs pressed), the right finish (galvanized where it counts), and the right supplier (proven QA, real test data). Then build a habit of cleaning, inspecting, and re-torquing. That’s how you turn parts into safety—and safety into productivity.
Looking for EN-tested, consistently manufactured putlog couplers with fast lead times and OEM options? APAC can help—ask for our latest catalog, batch-traceable QA, and a tailored quote for your fleet.
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