A 20xD solid carbide ultra-deep-hole drill developed for hardened steel and hardened mold steel. Reinforced cutting edges, through-tool internal coolant, optimized deep-hole flute geometry, and precision pilot guidance help control heat, evacuate chips, and maintain hole straightness over extended drilling depths.
The 20xD carbide drill for hardened steel is developed for demanding ultra-deep-hole applications where material hardness, cutting heat, long-distance chip evacuation, tool rigidity, pilot-hole accuracy, spindle runout, and hole straightness must all be carefully controlled.
Compared with 12xD and 15xD drilling, a 20xD drill has a significantly longer unsupported cutting section and chip evacuation path. Small errors in pilot-hole alignment, tool holding, spindle runout, coolant delivery, or chip formation can become increasingly significant as drilling depth increases. In hardened steel, these conditions may lead to cutting-edge chipping, excessive heat, chip packing, torque fluctuations, drill deflection, hole deviation, or sudden tool breakage.
This drill is manufactured from imported MG grade 0.8 μm tungsten carbide rods with 10% cobalt content. Combined with application-specific heat-resistant coating, reinforced cutting-edge preparation, optimized point geometry, extra-deep-hole flute design, controlled core geometry, precision pilot guidance, and through-tool internal coolant, it supports stable 20xD drilling in hardened steel and heat-treated steel components.
| Item | Description | Item | Description |
|---|---|---|---|
| Product Name | 20xD Carbide Drill for Hardened Steel | Drill Type | Solid Carbide Extra-Deep-Hole Drill |
| Hole Depth | 20xD | Application | Ultra-deep-hole drilling in hardened steel |
| Workpiece Material | Hardened steel, hardened mold steel, hardened tool steel, die steel and heat-treated alloy steel | Carbide Material | Imported MG Grade 0.8 μm Tungsten Carbide |
| Cobalt Content | 10% | Coating | ALTISIXN Wear-Resistant Coating |
| Passivation Control | ±0.003 mm | Edge Inspection |
|
| Service | Regrinding and Customization Available | Tool Life | Up to 80–150 Meters Under Suitable Machining Conditions |
Key Features
Made from imported MG grade 0.8 μm tungsten carbide with 10% cobalt content. The fine carbide grain structure provides a balance of hardness, toughness, edge strength, and dimensional stability required for ultra-deep hardened steel drilling.
An application-specific heat-resistant coating helps protect the cutting edges and flute surfaces against concentrated cutting temperature, abrasive wear, oxidation, and premature coating failure during hardened steel machining. Controlled edge preparation strengthens the cutting edge and helps reduce micro-chipping under high cutting loads.
Accurate point symmetry and cutting-edge geometry help the drill enter the pilot hole concentrically and maintain balanced cutting loads. Small directional errors at the beginning of a 20xD hole may become significantly larger at the final drilling depth.
The reinforced core and flute structure are designed to balance tool rigidity with sufficient chip evacuation space. For a 20xD carbide drill, excessive flute volume may reduce tool strength, while an overly thick core may restrict chip movement and coolant flow.
The 20xD carbide drill for hardened steel is suitable for ultra-deep-hole machining in CNC machining centers and automated production systems where material hardness, hole depth, chip evacuation, coolant delivery, and hole straightness must be carefully controlled.
Send us your material and hole requirements. Our team will recommend the right drill solution.
Landun CNC Tool is a carbide drill manufacturer focused on precision solid carbide drills and custom carbide drill solutions, supported by advanced grinding, strict inspection, and consistent edge preparation.
Production Facility
Geometry Accuracy Control
Edge Inspection Magnification
Edge Passivation Control
Our carbide drills are ground on German WALTER 5-axis grinding machines for sharp cutting edges, stable accuracy, and smooth drilling performance.
We use WALTER HELICHECK PLUS for contour inspection, keeping profile and radius control within 3 μm for reliable geometric precision.
Each carbide drill is inspected at 300x magnification to check edge quality and avoid chipping or saw-tooth defects before shipment.
Manual drill point honing and automatic rubber-bonded diamond abrasive polishing help improve tool life and control edge consistency within ±0.003 mm.
Common Questions
20xD means that the drill is designed for holes with a depth of up to approximately twenty times the drill diameter.
For example, a 5 mm drill may be used for a hole approximately 100 mm deep under suitable machining conditions.
At this drilling depth, pilot-hole accuracy, spindle runout, internal coolant, chip evacuation, machine rigidity, and hole straightness become critical process factors.
20xD hardened steel drilling combines two difficult conditions: high material hardness and an extremely long drilling depth.
Hardened steel generates high cutting forces and concentrated cutting heat, while chips must travel through a long flute before leaving the hole.
Poor chip evacuation, inadequate coolant, excessive runout, or inaccurate pilot guidance can lead to chip packing, torque fluctuations, edge chipping, drill deflection, hole deviation, and tool breakage.
Through-tool internal coolant should be considered a standard requirement for most 20xD hardened steel applications.
It delivers coolant directly to the cutting edge and helps carry chips through the long flute while controlling cutting temperature and reducing chip packing.
A precision pilot or guide hole is typically required for 20xD drilling.
The pilot hole establishes the correct entry position and drilling direction before the longer drill enters the workpiece.
Pilot-hole diameter, depth, tolerance, and geometry should be matched to the 20xD drill.
Yes, under suitable machining conditions.
For extra-deep blind holes, the usable drilling depth must account for the drill-point length and chip space.
Blind-hole applications also place greater demands on internal coolant and chip evacuation because chips cannot exit through the bottom of the workpiece.
Runout causes uneven cutting-edge loading and changes the initial drilling direction.
Because the hole is extremely deep, even a small angular deviation near the entrance can become a much larger positional error at the bottom or exit of the hole.
Low-runout tool holding and stable spindle condition are therefore especially important for 20xD drilling.
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