What is a chamfer?

A chamfer (also called a bevel, cant or arris) is an angled cut on the edge of a building element. Instead of a sharp 90° corner, the edge is cut at an angle — typically 45° — to create a flat, sloping surface.

Why use a chamfer?

Chamfers are applied for several reasons:

• Protection — sharp corners chip easily (arris damage). A chamfer makes the edge more robust
• Safety — rounded or chamfered edges prevent cuts and injuries
• Aesthetics — a chamfer gives a neat, professional appearance
• Formwork — in concrete formwork, triangular fillet strips (chamfer strips) are placed in the corners to create chamfers in the finished concrete

Sizes

Common chamfer sizes are:

• 5 × 5 mm — small chamfer, standard on timber window frames
• 10 × 10 mm — typical for precast concrete elements
• 15 × 15 mm or larger — for heavy construction and large precast units

Applications

• Concrete — chamfer strips in the formwork create bevelled edges on columns, beams and walls
• Timber — window frames, doors and skirting boards often receive a small chamfer with a plane or router
• Masonry — the edges of brick piers are sometimes chamfered
• Natural stone — sills and window ledges receive a chamfer to encourage water run-off

Related terms

• Bevel
• Formwork
• Arris
• Mitre
• Fillet strip

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