Short answer
With the Carbitron 300, a vibrating tungsten-carbide electrode deposits a fused 78 to 80 Rockwell C layer onto the cutting edge, typically 0.0002" to 0.001" thick depending on the tool. Deposit along the cutting edge, re-sharpen, then lightly stone the edge with a CBN or diamond stone. Hunter Products rates the result at 5x to 10x the life of standard tooling.
How the deposit works
The Carbitron 300 pairs an adjustable discharge power supply with a vibrating hand tool that holds a tungsten-carbide electrode. As the electrode repeatedly touches and lifts off the work, small arcs knock tungsten carbide off the electrode and deposit it into and onto the surface. The process is generally known as electro-spark deposition.
The deposit forms a true metallic bond with the tool at 78 to 80 Rockwell C. Because it is fused to the surface rather than sitting on top of it, it does not behave like a paint or a thin film coating.
Why shops do it
- Extend tool life: rated at 5x to 10x over standard tooling
- Self-sharpening cutting edges
- Resize and salvage worn tools instead of replacing them
- A non-brittle tungsten carbide surface with better thermal-shock and impact resistance
- Less downtime, fewer tool changes and less regrinding
Where to deposit and how much, by tool
| Tool | Deposit | Where | Then |
|---|---|---|---|
| Lathe bits, single-point tools | 0.0004" to 0.004" | Top side of the cutting edge | Re-sharpen by grinding the front |
| End mills | 0.0002" to 0.0006" | Cutting edges inside the flute, at the bottom and sides, along the full length | Re-sharpen |
| Counterbores | 0.0002" to 0.0006" | Same as end mills | Re-sharpen |
| Horizontal milling cutters | 0.0002" to 0.004" | Front face of each tooth along the cutting edge | Re-sharpen by grinding the land |
| Hobs | 0.0002" to 0.004" | Front face of each tooth along the cutting edge | Re-sharpen |
| Shell mills | 0.0002" to 0.0006" | Front face of the cutting surface along the edge | Re-sharpen |
| Reamers | 0.0002" to 0.0008" | Inside the flute along the cutting edge | Re-sharpen |
| Countersinks | 0.0002" to 0.0006" | Along the cutting edge inside the flute, full length | Re-sharpen |
| Taps | 0.0002" to 0.001" | Inside the flute along the cutting edge for 2 to 3 full threads | Re-sharpen dull taps before depositing |
| Thread chasers | 0.0002" to 0.001" | Along the top cutting edge | Re-sharpen dull chasers before depositing |
| Saws | 0.0002" to 0.001" | Front edge of each tooth; on very fine teeth, the sides instead | Re-sharpen |
Deposit thickness is set on the power supply from 0.0002" to 0.001" in 0.0002" steps. For recommendations above 0.001", contact us for the build-up procedure.
Step by step
- 01
Re-sharpen first if the tool is dull
Taps and thread chasers in particular should be sharp before depositing. Deposit onto a good edge, not a worn one.
- 02
Set the deposit thickness
Use the discharge intensity selector on the power supply to choose a thickness from 0.0002" to 0.001", based on the table above and how much build-up the tool can tolerate.
- 03
Deposit along the cutting edge
Connect the ground cable to the tool and work the vibrating electrode along the area shown for that tool type. On taps, take care not to nick the cutting edge.
- 04
Re-sharpen
Grind as listed for the tool, usually the front or the land, so the carbide sits right at the working edge.
- 05
Stone the edge
Lightly stone the deposit with a cubic boron nitride or diamond stone to remove burrs and get the sharpest edge.
What it costs to run
The Carbitron 300 is $495. Electrodes are $12.50 each in 1/8", 1/16" and 1/32" sizes, and a 1/8" x 2 1/2" electrode typically covers about 50 square inches at 0.0005" average thickness, so about $0.25 of electrode per square inch at that thickness. Cutting edges are small, so one electrode treats a lot of tools.
The unit runs on 110V, 60Hz at 4 amps (230V/50Hz available) with a 50% duty cycle and a 10-minute maximum continuous on-time.
Frequently asked questions
How much longer do tools last with tungsten carbide deposition?
Hunter Products rates Carbitron-treated tooling at 5x to 10x the life of standard tooling, depending on the tool and the work.
How hard is the tungsten carbide deposit?
78 to 80 Rockwell C. It forms a fused metallic bond with the tool surface.
How thick is the deposit?
Set on the power supply from 0.0002" to 0.001" in 0.0002" steps. The right amount depends on the tool and how much build-up it can tolerate.
Do I need to re-sharpen after depositing?
Yes, for cutting tools. Deposit along the cutting edge, re-sharpen as listed for the tool type, then lightly stone with a CBN or diamond stone.
What is electro-spark deposition?
A process where short electrical arcs between a consumable electrode and the work transfer electrode material into the surface. The Carbitron 300 uses a tungsten-carbide electrode in a vibrating hand tool.
Not sure how much carbide your tool needs?
Tell us the tool, the material it cuts or forms, and where it wears. The people who build the Carbitron will tell you how to apply it.