The job: Manufacture titanium bone screws with tight tolerances.

The challenges:

  • Titanium is an excellent material for bone screws, but it hardens as it heats up, making it tough to machine, leaving fine feather burrs.  These burrs must be removed without damaging or dulling the cutting edges on the screw. In the case of self-tapping screws, gentle removal is especially critical because it is easy to ruin the integrity of the flute.
  • The screw head may also require a textured finish that ends precisely before the threads.

Deburring and texturing bone screws with Comco’s Advanced Lathe.

Deburring the Threads

Two abrasives work best for this application: sodium bicarbonate and glass bead. Sodium bicarbonate gently removes burrs on a bone screw without dulling the cutting edges. Glass bead both removes fine feather burrs and creates a compressive layer on the surface of the threads. This layer helps to improve the fatigue life on the bone screw. Caution: Over-blasting—or blasting too forcefully for too long or with too much abrasive—rounds or dull most part edges. Therefore, it is essential to acutely monitor blast time and coverage when using glass bead.

Recommended Approach

  • Nozzle: 0.046” or 0.060” Hi/Performance
  • Pressure: 60-100 psi
  • Abrasive: 50 µ Sodium Bicarbonate or Glass Bead
  • Orifice: 0.030″

Texturing the Head

Some bone screws require a second blasting application: texturing. Texturing the surface on the head of the screw improves the mechanical bond with a swivel or another fixation device. MicroBlasting provides the precision to selectively texture this portion of the screw and using aluminum oxide to texture creates more surface area and greater points of contact between the screw and the device.

Recommended Approach

  • Nozzle: 0.030” Hi/Performance
  • Pressure: 50-80 psi
  • Abrasive: 50 µ Aluminum Oxide
  • Orifice: 0.025”

Your Partner for Industrial Engineering Solutions

  • Applied engineering with a deep understanding of precision parts

  • Providing the process at no additional cost to you

  • Sharing our skills & knowledge throughout our partnership

Dig Deeper

3 Ra Profiles

Need a consistent surface finish?

Not getting a consistent surface finish? Change your surface finish spec to include three measurable details. Continue reading
3 samples: 100% stepover, 50% stepover and 20% stepover (uniform finish)

How to calculate stepover

“Where did these stripes come from?” Learn how to avoid uneven part finishes.  Continue reading
Hold the nozzle at angle to avoid abrasive ricochet.

Automated Systems

When a manual MicroBlasting system cannot provide the output or meet your tolerance requirements; Comco’s automated systems deliver all the benefits of a manual system with greater precision and efficiency. Continue reading
5 Factors that Lead to Successful Deburring

5 Factors to Successful Deburring

In this quick video lesson, we break down the 5 factors that impact most deburring applications. When you’re done, you’ll know how to deburr…better! Continue reading
Colin Weightman


Email me or give me a call at 818-841-5500