APFDCBRT Bulldozes Core Barrel
APFCBR Cylindrical reverse spiral pebble stone drill bit
APFCBR Inner Spiral Pebble Stone
APFCBR Mesh Pebble Fishing Bit
APFBH-D Bucket Teeth Half-closing Drill
APFBH-R Intersecting Semi-closed Drill
APF-ZD Bucket Rotary Drill
APF-ZD pick-up cone bottom rotary drill
APFXKSYS-S1 Hard Rock Clearing and Expanding Drill
APFXKSYS-S2 Two-wing Rock Reaming Bit
APFXKSYS-S3 Three-wing Soil Reaming Bit