Dear Readers,
In the construction industry, one of the most commonly used tools is the spanner. This versatile tool is mainly used for gripping and turning fasteners like nuts and bolts. Spanners are tools made to give you a good grip and extra leverage when tightening or loosening rotary fasteners. Usually crafted from carbon steel or drop-forged steel, they come in a range of shapes and sizes to suit different needs.
Metric spanners (mm) and imperial spanners (inch) are both available, but the construction industry mostly uses the metric system. Metric spanners are labeled in millimeters (mm). The nominal size (e.g., M12) refers to the thread diameter, not the spanner size.
The best way to find the right spanner size is to measure the distance across the flat sides (AF) of the nut or bolt head with a measuring tool. If you don’t have one handy, you can refer to a size chart or use a general formula for standard bolts instead.
A general formula provides a good estimate for standard hexagonal metric bolts:
For bolts up to M14: Spanner size = (Bolt diameter × 1.5) + 1 mm.
(e.g., M8: (8 × 1.5) + 1 = 13 mm).
For bolts M16 and above: Spanner size = Bolt diameter × 1.5 mm.
(e.g., M16: 16 × 1.5 = 24 mm).
Spanners are essential tools in various industries including Construction, providing the necessary grip and torque to handle fasteners effectively.
