The ringlock rosette is the small, circular disc welded to the vertical standard of a ringlock system, and it sits at the heart of how the whole scaffold locks together. Every ledger, diagonal brace and transom that makes up a working platform is secured at one of these nodes. Because the rosette carries the connection forces of the entire structure, the steel it is made from matters as much as the geometry of the holes around its rim. This article explains why Q235 steel grade is the industry default for ringlock rosettes, what it means in practical terms, and what to look for when sourcing them for your next project.
What is a ringlock rosette?
A rosette, sometimes called a disc or collar plate, is a flat circular plate with a set of connection holes around its circumference. It is welded to the upright of the ringlock scaffolding system at regular spacing, usually around 500 mm apart. The standard design uses eight holes: four smaller holes receive the wedges that lock the horizontal ledgers in place, and four larger holes accept the diagonal braces that give the tower lateral stability. Because the wedge and the rosette engage by gravity, no loose bolts or extra fasteners are needed, which keeps erection fast and reduces the risk of missing parts on site.
What does Q235 steel grade mean?
Q235 is a Chinese carbon structural steel designation defined in the national standard GB/T 700. The letter Q stands for yield (qufu in Chinese), and the number 235 indicates a guaranteed yield strength of at least 235 MPa in the thinner plate range. It also offers a tensile strength in the region of 370–500 MPa, together with good ductility, uniform elongation and, crucially, excellent weldability and formability. That combination is exactly what a stamped and welded component such as a rosette needs.
For everyday comparison, the material behaves in a broadly similar way to S235JR in the European EN 10025 series common on international scaffolding jobs. That makes Q235 an easy material to specify, to test and to document when your scaffold must comply with EN and BS standards.
Why Q235 for the rosette rather than a higher grade?
Choosing the right steel grade is never simply about picking the strongest alloy available. Q235 sits in the sweet spot for a connecting plate for three reasons. First, the rosette transfers load through bearing and shear in the wedge pockets, and at the plate thicknesses normally used, Q235 already provides ample capacity without pushing component weight or cost up. Second, low-carbon carbon steel welds cleanly onto the standard tube, so the welded node stays sound and consistent through the production run. Third, the material stamps accurately, holding tight tolerances on hole position and edge profile, which is what keeps every ringlock bay interchangeable.
Where a project demands extra margin, such as heavy formwork support or very tall towers, suppliers also offer rosettes in Q355, which guarantees a higher yield and is better suited to the most demanding load cases. The two grades are dimensionally identical, so switching grades for a specific project does not change the layout of the system.
Typical sizes and dimensional consistency
Most ringlock rosettes are produced in a small range of sizes. Common outer diameters are 120 mm, 122 mm and 124 mm, with plate thicknesses from 8 mm up to 10 mm. The holes, normally four small wedge pockets interleaved with four larger brace slots, are punched in one operation so that every plate lines up precisely with its neighbour on the upright. Dimensional consistency is the quiet requirement that users only notice when it is missing: if one rosette is drilled out of position, ledgers no longer drop in smoothly anywhere on that run. A reliable supplier inspects hole pitch and diameter, plate flatness and weld integrity on every batch.
Surface treatment protects the steel
Raw Q235 rosettes are susceptible to rust, so the finish is part of the spec, not an afterthought. Hot-dip galvanizing (HDG) is the most common choice for heavy-duty and permanent installations because the thick zinc layer gives long service life outdoors. Electro-galvanized rosettes offer a smooth, bright finish at a lower cost for lighter, short-term use, while powder coating or pre-galvanized sheet is selected when a consistent painted appearance is wanted across the whole system. Matching the rosette finish with the rest of the ringlock components keeps the entire structure uniform and easier to maintain.
Buying with confidence
Because the rosette is the hinge of the whole system, it pays to buy from a manufacturer that can document the steel grade, the heat, the plate thickness and the treatment applied. Bythai Scaffolding supplies ringlock rosettes in Q235 and Q355 with hot-dip, electro-galvanized and powder-coated finishes, all manufactured under an ISO9001 quality system and in line with international EN and BS standards. With more than a decade of export experience serving construction, oil and gas and distribution clients, and flexible MOQ and OEM options, the company is set up to match rosettes to the exact upright and load requirements of your project without over-specifying.
Choosing a Q235 ringlock rosette is less about chasing the highest number and more about getting a well-connected, well-welded and well-finished node that holds the whole tower together for years. When you know the grade, the dimensions and the finish your system needs, you can buy a proven component with confidence.