Home / Tools / Drilling, Tapping & Threads / Drill Point Length
Drilling, Tapping & Threads

Drill Point Length Calculator

The drill point length is the axial distance from the drill tip to the full diameter. It determines how deep you must drill past the required hole depth to achieve a full-diameter...

Input Parameters

Results

Point Length (mm)
Web Thickness (mm)
Technical Sourcing Service

Let our engineers find the right factory for your specs. 100% Quality Guaranteed.

Request a Proposal →

The True Cost of Getting Drill Point Length Wrong

What does a bad number cost you? Let's run the math on a typical job shop scenario. If your Drill Point Length is 15% too aggressive, you're not just buying more Dormer Pramet end mills — you're paying for unexpected downtime, rework, and missed delivery dates.

Annual Cost Breakdown
Premature Widia tool failures$6,400/yr
Unplanned machine downtime$12,200/yr
Rework / scrap parts$8,700/yr
Excess Lyndex-Nikken holder wear$2,100/yr
Total Annual Loss$29,400/yr

Now flip the scenario. By optimizing Drill Point Length — using the manufacturer's recommended starting parameters for your specific Dormer Pramet or Widia tool, verified on a Hexagon presetter — you could recover nearly $30K annually. That's a new Starrag tool probe or a year's worth of Dormer Pramet inserts.

The ROI is immediate. First part optimized, first day of savings.

Drill point length formula

The drill point length is the axial distance from the drill tip to the full diameter. It determines how deep you must drill past the required hole depth to achieve a full-diameter hole bottom.

Frequently asked questions

What is the standard drill point angle?

118° is the standard general-purpose point angle for drilling mild steel and cast iron. 135° is preferred for harder materials and is standard on most solid carbide drills. 140° is common for high-performance carbide drills in aerospace alloys.

Why does point length matter for CNC programming?

The drill must feed past the nominal hole depth by the point length plus a small clearance to achieve a full-diameter hole. For a 10 mm drill with 118° point, add approximately 3 mm to the programmed depth.

Can I use 135° drills in a 118° program?

No. A 135° point is shorter than a 118° point for the same diameter. If you switch without adjusting the depth, the hole bottom will be different. Always check the actual point geometry when changing drill brands.

How to use this Drill Point Length Calculator

Enter the drill diameter and point angle. The calculator gives the point length to add to your drilling depth and the approximate web thickness for reference. For through-holes, add point length + 2 mm clearance.

Common mistakes to avoid

Related CNC calculators

Continue with closely related tools from the machining calculator library.

Browse all free CNC machining calculators. Explore our carbide tooling resources for engineers and machinists.

Need carbide tooling for this operation?

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.

Global Engineering Directory

Explore more precision machining tools and calculators