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Adjustable steel column clamps with wedges set in a square

Column Clamps

Adjustable steel clamps for shuttering square and rectangular concrete columns, in stock to buy or hire

  • Fits columns 229mm to 1,270mm
  • Locks tight with four wedges
  • Wedges chained so nothing's lost
  • In stock to buy or hire
  • Fast delivery across the UK

Column clamps are adjustable steel bars that lock tightly around timber or steel shuttering when forming square and rectangular concrete columns. They are designed to hold the form square against wet concrete pressure without internal tie rods. We hold Sizes 1, 2 and 3 in stock to buy outright or hire by the week, with fast delivery nationwide.

Because the bars are adjustable, one set will fit a wide range of column widths. On site, you may also hear column clamps referred to as shuttering clamps, formwork clamps, pillar clamps or column shackles.

Typical Applications

Column clamps are used wherever you need to pour concrete into a square or rectangular box:

  • Square and rectangular structural columns from 229mm to 1,270mm wide
  • Brickwork piers, portal frame encasements and entrance pillars
  • Basement and staircore stub columns where crane-handled panels aren't needed
  • Jobs with varying column widths that can all be formed with the same adjustable set

How Column Clamps Work

Once you have formed the column form from either steel or plywood with timber battens, the column clamp is introduced as a set of four slotted bars wrapping the outside of the form at various height intervals. You then tap the column clamp's tensioning wedges home with a hammer. The wedges pull the steel arms tight against the shutter to hold the pressure of the wet concrete, with no tie rods through the column and no tie holes to make good afterwards.

When the concrete has cured, a tap of the hammer will knock the wedges out and the form can be stripped in seconds. Each wedge is chained to its arm so pins don't get lost. A full set weighs between 11.5kg and 25.8kg, so they are easy to carry, fit and strike by hand and without a crane.

Buy or Hire Column Clamps

A set of SEL column clamps should last dozens if not hundreds of pours. Column clamps have no moving parts to wear out and come with zinc-plated or powder-coated steel arms and chained wedges. If you pour columns, piers or foundations regularly, buying your own stock of clamps outright will quickly pay for itself.

We hold all three sizes in stock for direct purchase from our depots in Bristol, Cardiff and London, with fast delivery nationwide. We also hire them out by the week. Contact your nearest SEL depot for sale prices or weekly hire rates.

Column Clamps: Common Questions

What sizes of column clamps does SEL stock?
SEL stocks column clamps in Sizes 1, 2 and 3 to buy or hire. Size 1 adjusts from 228.6mm to 546.1mm (9" to 21.5") and weighs 11.5kg per set. Size 2 adjusts from 330.2mm to 889.0mm (13" to 35") and weighs 16.0kg per set. Size 3 adjusts from 596.9mm to 1,270.0mm (23.5" to 50") and weighs 25.8kg per set. Always include the thickness of your plywood face and timber backing battens when selecting your clamp size.
Can I buy column clamps outright from SEL?
Yes, you can buy column clamps directly from Site Equipment Limited as well as hire them by the week. We hold Sizes 1, 2 and 3 in stock across our Bristol, Cardiff and London depots for fast delivery nationwide. Many contractors choose to buy their own sets because the steel bars and chained wedges will last through hundreds of pours.
Are shuttering clamps, formwork clamps and pillar clamps the same thing as column clamps?
Yes, shuttering clamps, formwork clamps, pillar clamps and column shackles are all site terms for adjustable steel column clamps. They all refer to the same set of four slotted steel bars and wedges used to lock shuttering around a concrete column.
Can column clamps form rectangular concrete columns as well as square ones?
Yes, column clamps can form rectangular concrete columns as well as square ones. Each arm adjusts on its own along the slots, so you can set two opposite bars to the shorter face and the other two to the longer face. For wide rectangular sections, you can also combine two arms from a smaller clamp size with two from a larger size.
How far apart should column clamps be spaced vertically?
Vertical spacing for column clamps depends on the column height, cross-section and concrete pour rate. Wet concrete pushes hardest at the bottom of the shutter, so clamp sets are spaced closer together near the base (usually starting 150mm to 200mm above the kicker) and wider apart towards the top. If you need engineered spacing calculations for a tall or heavy column pour, our in-house team can provide a BS 5975 Temporary Works Design.
When should I use column clamps instead of modular panel formwork?
Column clamps are usually the simplest and lowest-cost choice when you have a small number of square or rectangular columns shuttered in plywood and timber. A full set weighs between 11.5kg and 25.8kg, so two people can fit and strike them by hand without a crane. If your project involves a long run of large columns, lift cores or walls up to 3.0m high, our modular Frami formwork panel system is faster to form.

Column Clamp Sizes

SpecificationMinimum Clamping SizeMaximum Clamping SizeSet Weight (4 Arms & Wedges)
Size 1 (No. 1)228.6mm (9")546.1mm (21.5")11.5kg
Size 2 (No. 2)330.2mm (13")889.0mm (35")16.0kg
Size 3 (No. 3)596.9mm (23.5")1,270.0mm (50")25.8kg

Material and Component Properties

Key Component Properties
Set Configuration4 slotted steel arms with 4 chain-tethered wedge pins
Wedge Pin Dimensions40 × 280 × 6mm
Material GradeQ235 structural carbon steel
Surface FinishPowder-coated / zinc-plated

Clamping dimensions denote the internal clear aperture between the clamp arms. Remember to account for the thickness of your plywood sheathing and timber backing battens when sizing clamps for your column section.

Questions? Talk to SEL about Column Clamps

Our team is responsive, experienced and happy to help.

Equipment commonly paired with column clamps on a concrete pour

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