Lihao Technology · Professional HSS-E Cobalt Countersink Manufacturer · Factory in Changan, Dongguan
| Countersink Angle | Screw Standard | Common Applications |
|---|---|---|
| 90° | Metric countersunk screws (GB/T 819) | Most common, sheet metal, enclosures, machinery |
| 82° | Imperial countersunk screws (ANSI B18.6.3) | Export products, ANSI equipment |
| 100° | Aerospace countersunk screws (MS24694) | Aerospace, military |
| 120° | Large flat head screws, special countersinks | Thin sheets, decorative panels |
| 60° | Special tapered holes, locating holes | Special tooling, locating |
| 110° | Some imperial countersunk screws | Imperial equipment, imported machinery |
| Screw Size | Recommended Countersink Diameter | Countersink Diameter Reference |
|---|---|---|
| M3 | φ8 | φ5.5 |
| M4 | φ10 | φ7.0 |
| M5 | φ12 | φ8.5 |
| M6 | φ14 | φ10.0 |
| M8 | φ16-φ20 | φ13.0 |
| M10 | φ20-φ25 | φ16.0 |
| M12 | φ25-φ30 | φ18.0 |
| Workpiece Material | Recommended Tool Material | Recommended Coating | Notes |
|---|---|---|---|
| Stainless steel (304/316) | Cobalt HSS-E | TiAlN nano coating | No welding, 3x tool life |
| Cold-rolled sheet / carbon steel | Cobalt HSS-E | TiN/TiCN | Great value |
| Aluminum alloy | Cobalt HSS-E | TiAlN/DLC | Anti-welding, smooth finish |
| Copper / brass | HSS | Uncoated / TiN | Soft materials, standard tools suffice |
| Titanium / high-temperature alloy | Cobalt HSS-E | TiAlN nano coating | Cobalt HSS + coating required |
1. Angle principle: Countersink angle = screw head angle. If unsure, measure the screw head or contact technical support.
2. Diameter principle: Countersink diameter ≥ countersink hole diameter, 2-3mm larger recommended to avoid edge contact.
3. Stainless steel: Use cobalt HSS + TiAlN coating with coolant and lower speed, otherwise welding and chipping may occur.
4. Thin sheets: Reduce feed and depth of cut to avoid sheet deformation and proud screw heads.
5. Custom sizes: When standard sizes do not fit, we custom-make angles, diameters, shanks and flute lengths - 7-day delivery, MOQ 10 pcs.