Counterbore Hole Size Chart for Pan Head Screws (DIN 85)
DIN 85 counterbore hole size chart for pan head screws, including pilot hole diameters for close, normal, and loose fits, counterbore diameters, and depths (millimeters)
Pan Head Screw Counterbore Hole Chart (DIN 85)
| Fastener Size | Pilot Hole Diameter (mm) | Counterbore Diameter (mm) | Counterbore Depth (mm) | ||
|---|---|---|---|---|---|
| Close Fit (H12) | Normal Fit (H13) | Loose Fit (H14) | |||
| M1.6 | 1.7 | 1.8 | 2 | 3.5 | 1.5 |
| M2 | 2.2 | 2.4 | 2.6 | 5 | 2.1 |
| M2.5 | 2.7 | 2.9 | 3.1 | 6 | 2.6 |
| M3 | 3.2 | 3.4 | 3.6 | 7 | 2.9 |
| M3.5 | 3.7 | 3.9 | 4.2 | 8 | 3.1 |
| M4 | 4.3 | 4.5 | 4.8 | 9 | 3.6 |
| M5 | 5.3 | 5.5 | 5.8 | 11 | 4.5 |
| M6 | 6.4 | 6.6 | 7 | 13 | 5.4 |
| M8 | 8.4 | 9 | 10 | 18 | 6.8 |
About DIN 85 Counterbore Hole Sizes for Pan Head Screws
This DIN 85 counterbore hole size chart for pan head screws provides standardized metric dimensions based on the Deutsches Institut für Normung (DIN) specifications. It lists the recommended pilot hole diameters for close fit (H12), normal fit (H13), and loose fit (H14) tolerances, as well as the corresponding counterbore diameters and counterbore depths in millimeters.
These DIN 85 counterbore dimensions ensure accurate screw seating, sufficient head clearance, and consistent mechanical performance in metric fastening applications. This reference chart is useful for engineers, machinists, and designers working on projects that require adherence to DIN 85 pan head screw specifications, including:
- Mechanical and product design using DIN 85 pan head machine screws in metric systems.
- Machining, drilling, and fabrication processes requiring precise pilot hole and counterbore preparation for standard fasteners.
- Assembly and quality control operations ensuring flush seating, proper fit, and alignment of screw heads.
Key Terms in the DIN 85 Counterbore Hole Chart
- Pilot Hole Diameter (H12 / H13 / H14): The drilled hole diameter defining the screw shank clearance, categorized by tolerance grade.
- Counterbore Diameter: The circular recess machined into a part to allow the pan head screw to sit flush or slightly below the surface.
- Counterbore Depth: The recess depth corresponding to the head height of the DIN 85 pan head screw.
- DIN 85 Standard: The German Industrial Standard defining the dimensions, tolerances, and geometry of pan head screws used in mechanical assemblies.
Referencing this DIN 85 pan head screw counterbore hole size chart supports accurate part design, consistent manufacturing results, and compliance with international metric fastener standards. Correct use of these dimensions ensures reliable fit, reduces rework, and enhances the overall quality of mechanical assemblies.