Counterbore Hole Size Chart for Low Socket Head Screws (DIN 7984)
DIN 7984 counterbore hole size chart for low socket head screws, including pilot hole diameters for close, normal, and loose fits, counterbore diameters, and depths (millimeters)
Low Socket Head Screw Counterbore Hole Chart (DIN 7984)
| Fastener Size | Pilot Hole Diameter (mm) | Counterbore Diameter (mm) | Counterbore Depth (mm) | ||
|---|---|---|---|---|---|
| Close Fit (H12) | Normal Fit (H13) | Loose Fit (H14) | |||
| M4 | 4.3 | 4.5 | 4.8 | 8.0 | 3.3 |
| M5 | 5.3 | 5.5 | 5.8 | 10.0 | 4.3 |
| M6 | 6.4 | 6.6 | 7.0 | 11.0 | 4.8 |
| M8 | 8.4 | 9.0 | 10.0 | 15.0 | 5.8 |
| M10 | 10.5 | 11.0 | 12.0 | 18.0 | 7.3 |
| M12 | 13.0 | 13.5 | 14.5 | 20.0 | 8.3 |
| M16 | 17.0 | 17.5 | 18.5 | 26.0 | 10.8 |
| M20 | 21.0 | 22.0 | 24.0 | 33.0 | 13.0 |
| M24 | 25.0 | 26.0 | 28.0 | 40.0 | 15.0 |
| M30 | 31.0 | 33.0 | 35.0 | 50.0 | 18.5 |
| M36 | 37.0 | 39.0 | 42.0 | 58.0 | 22.5 |
About DIN 7984 Counterbore Hole Sizes for Low Socket Head Screws
This DIN 7984 counterbore hole size chart provides engineers, machinists, and designers with standardized dimensions for low socket head cap screws according to the German DIN 7984 standard. It lists pilot hole diameters for close fit (H12), normal fit (H13), and loose fit (H14) conditions, as well as the recommended counterbore diameters and counterbore depths for each metric screw size.
Using standardized DIN 7984 counterbore dimensions ensures proper head clearance, accurate screw seating, and consistent assembly quality. This data is essential for:
- Mechanical and design engineers specifying low profile socket head screws in assemblies with limited clearance.
- Machinists preparing pilot holes and counterbores that meet DIN 7984 fit classes for precision fastening.
- Manufacturers ensuring compatibility with European DIN standards for interchangeability and quality assurance.
Key Terms in the DIN 7984 Counterbore Chart
- Pilot Hole Diameter (H12 / H13 / H14): The initial drilled hole that defines the bolt clearance based on fit tolerance.
- Counterbore Diameter: The circular recess that allows the screw head to sit flush or slightly below the surface.
- Counterbore Depth: The measured vertical depth of the machined recess corresponding to the head height of a DIN 7984 screw.
- DIN 7984 Standard: The Deutsches Institut für Normung specification that defines the dimensions and tolerances for low socket head cap screws used in metric engineering applications.
Referencing the DIN 7984 low socket head screw counterbore hole size chart ensures consistent fit, dimensional accuracy, and mechanical reliability in precision assemblies. These values support efficient fastener installation, standardized design practices, and high-quality manufacturing in metric mechanical systems.