Counterbore Hole Size Chart for Pan Head Screws (ISO 7045)
ISO 7045 pan head screw counterbore hole size chart, including pilot hole diameters for close, normal, and loose fits, counterbore diameters, and depths (millimeters)
Pan Head Screw Counterbore Hole Chart (ISO 7045)
| 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 | 2.0 | 3.5 | 1.5 |
| M2 | 2.2 | 2.4 | 2.6 | 5.0 | 2.1 |
| M2.5 | 2.7 | 2.9 | 3.1 | 6.0 | 2.6 |
| M3 | 3.2 | 3.4 | 3.6 | 7.0 | 2.9 |
| M4 | 4.3 | 4.5 | 4.8 | 9.0 | 3.6 |
| M5 | 5.3 | 5.5 | 5.8 | 11.0 | 4.5 |
| M6 | 6.4 | 6.6 | 7.0 | 13.0 | 5.4 |
| M8 | 8.4 | 9.0 | 10.0 | 18.0 | 6.8 |
| M10 | 10.5 | 11.0 | 12.0 | 24.0 | 8.3 |
About ISO 7045 Counterbore Hole Sizes for Pan Head Screws
This ISO 7045 counterbore hole size chart for pan head screws provides standardized metric dimensions according to the International Organization for Standardization (ISO) specifications. It includes recommended pilot hole diameters for close fit (H12), normal fit (H13), and loose fit (H14), as well as the corresponding counterbore diameters and counterbore depths in millimeters.
Using accurate ISO 7045 counterbore dimensions ensures proper screw seating, head clearance, and consistent mechanical performance in metric fastening applications. This reference is essential for engineers, machinists, and designers working with ISO 7045 pan head screws, including:
- Mechanical and product design projects requiring ISO 7045 pan head machine screws in metric systems.
- Machining, drilling, and fabrication processes that need precise pilot hole and counterbore preparation for standard fasteners.
- Assembly and quality control operations ensuring proper fit, alignment, and flush seating of screw heads.
Key Terms in the ISO 7045 Counterbore Hole Chart
- Pilot Hole Diameter (H12 / H13 / H14): The drilled hole diameter defining screw shank clearance, categorized by tolerance grade.
- Counterbore Diameter: The circular recess machined to allow the pan head screw to sit flush or slightly below the surface.
- Counterbore Depth: The vertical depth of the recess matching the head height of the ISO 7045 pan head screw.
- ISO 7045 Standard: The International Organization for Standardization specification defining dimensions and tolerances for metric-series pan head screws used in mechanical assemblies.
Consulting this ISO 7045 pan head screw counterbore hole size chart ensures consistent part design, precise manufacturing, and compliance with international metric fastener standards. Proper use of these dimensions enhances assembly quality, reduces errors, and improves overall reliability in mechanical systems.