What does across flats mean?
Width across flats is the distance between two parallel surfaces on the head of a screw or bolt, or a nut, mostly for torque transmission by positive locking.
What does AF on a spanner mean?
AF can stand for American Fractional; another term used for imperial. However, when applied to metric sockets, AF means ‘Across Flats’. This means a 19mm AF socket will fit a nut or bolt head that measures 19mm across its flats.
How do you work out a bolt across a flat?
Width of the nut across the flat surface (known as size across flat) = (1.5 × D) + 3 mm. The diameter of the nut = D in mm. The thickness of the nut = (0.8 × D) to D. The radius of front chamfer = 1.5 × D.
What spanner size is M8?
13
| Metric | ||
|---|---|---|
| Thread Size | Spanner Size A/F DIN (mm) | Spanner Size A/F ISO (mm) |
| M8 | 13 | 13 |
| M10 | 17 | 16 |
| M12 | 19 | 18 |
What is a hexagon flat?
A hexagon is a 6-sided polygon (a flat shape with straight sides).
What is the difference between AF and Imperial?
Imperial are another range of sizes completely;tend to be found on older UK vehicles. Most people take imperial to be inch sizes which are AF. If you’re thinking of Whitworth then you’ll struggle to get a whit set for cheap money these days. Most AF sizes are useful for when the metric nut is rounded etc.
What is 16mm in AF?
This table is the chart for publication of information of wrench sizes in inches (US) and millimeters (metric), as well as British spanner size information….Wrench Size And Conversion Table.
| Inches | Millimeters | Spanner |
|---|---|---|
| 0.625 | 5/8 AF | |
| 0.630 | 16mm | 16mm |
| 0.669 | 17mm | 17mm |
| 0.686 | 11/16 AF |
What size nut fits a 1/2 bolt?
US Nut Size Table
| Size | Diameter* | |
|---|---|---|
| Hex Nut | Machine Screw Nut | |
| 1/2″ | 3/4″ | – |
| 9/16″ | 7/8″ | – |
| 5/8″ | 15/16″ | – |