Bahco 9045-B-400 precision steel square, 400 mm (9045-B-400)

The Bahco 9045-B-400 carpenter's square is a steel layout tool designed for accurate measurement and angle marking in woodworking. Its black finish and sturdy construction provide a stable reference edge for marking, checking squareness, and measuring short distances during carpentry and joinery tasks. The tool combines a 41 cm blade with a 17 cm tongue to give a compact, easy-to-handle square suitable for workshop and on-site use.

Advantages

The durable steel construction ensures long service life and resistance to wear under regular use. The black finish reduces glare and improves contrast against pencil or marker lines. With a relatively light weight of 245 g, the square is easy to position and hold without compromising rigidity. The combination of blade and tongue lengths provides clear, reliable 90° references for layout, cutting checks and assembly alignment.

Suitable for

• Marking and checking right angles on timber and sheet materials
• Setting up saws, routers and jigs to ensure perpendicular cuts
• Measuring short straight runs and transferring measurements
• General carpentry, joinery and furniture making tasks

Key specifications

• Material: steel with protective black finish
• Blade length: 41 cm
• Tongue length: 17 cm
• Weight: approximately 245 g
• Shape: fixed 90-degree carpenter's square

How to use

Place the inner corner of the square against the workpiece edge so both blade and tongue make full contact with the surfaces to be referenced. For marking, hold the square firmly to prevent movement and scribe a line along the blade or tongue using a pencil or marking knife. To check squareness, align one arm of the square with a known surface and inspect the contact along the opposite arm; any gap indicates deviation. Use the square as a guide for setting cutting tools or verifying assembled joints by repeating the positioning and visual inspection steps.

Recommendations

Store the square in a dry place to prevent corrosion and avoid dropping or bending forces that could affect the 90° accuracy. Clean sawdust and debris from the edges before precision layout to maintain consistent contact. For highest accuracy, periodically check the square against a certified straight edge or machined reference.