carbide drill feeds and speeds chart. Get instant Countersink Depth (mm), Drill Point Depth (mm) for your machining parameters.
Let our engineers find the right factory for your specs. 100% Quality Guaranteed.
Request a Proposal →What does a bad number cost you? Let's run the math on a typical job shop scenario. If your Countersink Depth is 15% too aggressive, you're not just buying more Tungaloy end mills — you're paying for unexpected downtime, rework, and missed delivery dates.
| Premature Sumitomo Electric tool failures | $6,400/yr |
| Unplanned machine downtime | $12,200/yr |
| Rework / scrap parts | $8,700/yr |
| Excess Schunk holder wear | $2,100/yr |
| Total Annual Loss | $29,400/yr |
Now flip the scenario. By optimizing Countersink Depth — using the manufacturer's recommended starting parameters for your specific Tungaloy or Sumitomo Electric tool, verified on a Renishaw presetter — you could recover nearly $30K annually. That's a new Okuma tool probe or a year's worth of Tungaloy inserts.
The ROI is immediate. First part optimized, first day of savings.
A countersink creates a conical recess for a flat-head fastener to sit flush with or below the surface. The depth depends on the head diameter of the screw and the countersink angle (typically 82 deg for inch fasteners, 90 deg for metric).
Historical convention. ANSI B18.6.3 specifies 82 deg for inch flat-head screws. ISO 7721 specifies 90 deg for metric. The difference is small enough that many shops use a 90 deg countersink for both -- it slightly undercuts the head but is functionally fine for most applications.
Use a countersink gauge (dial depth gauge with a conical tip) or a Deltronic pin method: place a known-diameter pin in the countersink and measure the height above the surface. Calculate depth from the pin diameter and protrusion. Alternatively, use the screw itself as a go/no-go gauge -- it should sit flush to 0.1 mm below the surface.
Yes, for small screw sizes (under M5 or #10) and light-duty applications. The 60 deg angle of a centre drill differs from standard countersink angles, so the screw head won't seat perfectly. For production, use the correct-angle dedicated countersink tool.
Enter the countersink diameter (screw head diameter) and the countersink angle. The calculator gives the depth to feed the countersink tool. Add 0.05-0.1 mm for flush seating; add 0.2-0.3 mm for below-flush (for filling or covering).
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Use the calculator freely. If the result points to a tooling or process problem, we can source the exact carbide tooling you need from vetted factories in China. Compare factory-direct pricing.
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