Bit Wear Patterns

1. New Drill Crown

All Thriftline products have a serial number stamped on the side to assist in performance tracking and for ease of ordering.

2. Face Glazed

Diamond polished and metal bound. Sand blast face or use other recommended method to re-expose diamonds. Try again with RPI (RPC) in the 200/250 range (80/100) range. If face glazes repeatedly, change to higher series drill bit.

3. Convex Face Wear

Rounded to outside diameter. Insufficient water flow - check pump and rod string for leaks, increase pump output.

4. Outside Diameter Gauge Loss

Vibration - alter RPM, lack of circulation flow rate. Drill bit reaming down, undersized hole - check reaming shell gauge and replace if undersized.

5. Ideal Wear Pattern

Relatively flat wear pattern with slightly chamfered sides.

6. Burnt. Lack of Water

Check pump and rod string for leaks, check inner tube adjustments. Maintain coolant flow rates.

7. Normal Retirement

Full depth of impregnation evenly consumed.

8. Concave Face Wear

Rounded to inside diameter, often caused by excessive penetration rate for RPM used RPI (RPC) too low. Also can be caused by core grinding, over drilling.


9. Cracked Waterways

Excessive drill bitload, dropped rods, free fall of wireline inner tube in dry hole, drill bit crushed by rod holder or foot clamp.


10. Inside Diameter Gauge Loss

Overfeeding - increase RPI (RPC), Broken formations - cement or change to a lower series drill bit. Drilling over lost core - check core barrel. Insufficient drilling fluid - check inner tube length adjustment, check pump and rod string for leaks, increase pump output.

11. Excessive Diamond Exposure

Matrix abrades away before diamond has worn sufficiently, resulting in high diamond exposure and pre-mature diamond release with low drill crown life. Caused by overfeeding or over drilling. Increase RPI (RPC), or change to a lower series drill crown.