Pins, bolts and clips
Loose bolts, pins and clips that join lattice girders, standard joints and telescopic parts and keep those connections from working loose.
Also called: locking pin, R-clip, split pin, spring cotter, toe board bolt, connecting bolt
They are small, inconspicuous and tend to end up loose in a box in the yard, yet a whole scaffold section can depend on them. Bolts join components that transmit forces: two lattice girders over a spigot, a standard to the one below, a telescopic bracket at the chosen extension. Clips make sure the bolt stays where it belongs. Without them, vibration, wind or a knock while carrying material would loosen the connection, which over a doorway bridged by lattice girders would be disastrous.
Types
- Locking pins: plain steel bolts with a head and a cross hole, used for tension-proof standard joints on modular scaffolds or to connect lattice girders. Diameters around 12 mm are common; the exact design is set by the manufacturer.
- R-clips and split pins: pushed through the cross hole of the bolt. The R-shaped spring clip is the most common; simple wire split pins appear mainly on older parts.
- Securing pins: fix adjustable parts such as telescopic brackets or extendable props in the chosen position.
- Toe board bolts and special bolts: short bolts or screws with nuts for toe boards or spigots. Where the instructions allow it, a specified M12 bolt with nut can replace a locking pin.
The material is practically always galvanised steel. Do not confuse these loose parts with spigots and pins welded to frames, which belong to the component and are inspected with it. Pins that combine bolt and retainer in one part are covered under drop-lock pin and spring clip.
Fitting them properly
Align the components until the holes line up exactly; do not hammer them into place. Insert the bolt from the side the instructions specify, often from above or from outside, so that it cannot drop out if the clip is lost. Push the clip right through the cross hole and check that its bow lies against the bolt. When dismantling, pull the clip first, then the bolt, and put both straight into a bucket or mesh box instead of leaving them on the deck.
What goes wrong
- A bolt without its clip is only half fitted, one of the most frequent findings on bridging structures.
- A bolt that is too thin has play and wears the hole oval over time.
- Threaded rod, nails or random screws from a DIY store have different strengths and are no substitute.
- Bent or heavily rusted bolts, tired clips and worn holes in the mating part are scrap.
Small parts cost little but are missing exactly when you need them. When you buy used lattice girders or brackets, order the matching bolts and clips at the same time, and count small parts before each job. Many girders and pallets have holes for parking the bolts directly on the component. See the accessories section.