Wedge head and wedge
The slotted head on ledgers, braces and brackets that slides over the rosette and is locked by a driven wedge – a rigid node with no bolts.
Also called: ledger head, wedge connector, ledger end, wedge connection, brace head
At the heart of every modular scaffold is an inconspicuous pair: the wedge head at the end of a ledger and the wedge that locks it to the rosette or perforated disc. In a few movements they create a node that transfers load in all directions – without a single bolt or coupler.
Ledgers, diagonals and brackets attach at fixed heights all round the standard, often in several directions at once; the discs typically sit every 0.50 m. That makes the system flexible for curves, stair towers and industrial work. Without tight wedges, however, the node would only be hooked on loosely – the scaffold would wobble and could deform under load.
Design and variants
The wedge head is a slotted cast or forged steel part welded to the tube of the component. Its slot fits exactly over the disc. The wedge passes through a vertical opening in the head and on through a hole in the disc. On many systems the wedge is captive, so it cannot fall off.
- Small holes in the disc centre the part automatically at a right angle – ideal for tubular ledgers and deck transoms.
- Large holes allow free angles, for diagonals and oblique connections.
- Fixed heads sit rigidly on ledgers; swivel heads on diagonals take up the slope.
- Wedge-head couplers connect an ordinary tube to the disc via a wedge head – handy for special solutions.
Fitting
- Slide the head over the disc until the slot embraces it completely.
- Push the wedge through the head and the matching hole – the part is already secured against slipping off.
- With long ledgers, rest the far end with its wedge inserted first, then hook in the near end, so nothing can drop.
- Align every part at the node before driving any wedge.
- Strike the wedge with a hammer of roughly half a kilo until it noticeably bounces back.
- Check that the wedge is tight and the head bears fully on standard and disc.
To dismantle, the wedge is knocked up from below. Take care with load-bearing parts such as diagonals – they must not come loose while anything still stands above.
Faults and used parts
- Hooked in is not fixed. An undriven wedge transmits hardly any force; drive it immediately after fitting.
- Oversized hammer: heavy club hammers damage wedge and head; a normal scaffold hammer is enough.
- Bent or cracked wedges are rejected, as are heads with an opened slot.
- Concrete in the head stops it seating.
- Inspect the weld between head and tube for hairline cracks.
- Buying used ledgers and braces: test each head briefly – does it slide easily over a disc, is the wedge there and straight? Missing wedges can be replaced, deformed heads cannot.
Which components may be combined with which discs is governed solely by the documentation and approval of the system. Used ledgers with heads in good order are listed under ledgers.