1. Drilling tool (basic forming)
Core function: Open up the deep hole foundation channel, determine the position and depth of the hole.
Common types: gun drill, BTA drill, spray suction drill, DF drill (same as the previous classification of deep hole drill bits, it is the core starting tool for deep hole machining).
Applicable scenarios: Fromφ 2mm small hole toφ 300mm large hole, initial drilling with a depth to diameter ratio of 5-100 times.
2. Hole expanding tool (enlarged)
Core function: Expand the aperture on the basis of drilling, correct the roundness and straightness of the hole, and lay the foundation for precision machining.
Common types: deep hole drilling (with multiple guide blocks, strong rigidity), and reversible drilling tool.
Applicable scenarios: After drilling, the aperture needs to be fine tuned (expanded by 0.5-5mm), or the roughness of the hole wall is poor.
3. Reaming tool (accuracy improvement)
Core function: To achieve deep hole accuracy and surface quality, and reduce roughness.
Common types: solid hard alloy deep hole reamer, guide bar reamer, coating reamer.
Applicable scenarios: High precision requirements (IT7-IT9 levels), surface roughness Ra≤ 1.6-m deep hole precision machining.
4. Boring tools (for machining large/irregular holes)
Core function: Processing large-diameter deep holes, irregular deep holes, or correcting severe deviations after drilling.
Common types: deep hole boring tool (single blade/multi blade), adjustable boring tool holder, CNC deep hole boring tool.
Applicable scenarios:φ Large deep holes over 30mm, or high-precision machining that requires ensuring hole coaxiality and cylindricity.