UTOOL Twist Drill Bit-HSS (High-Speed Steel) twist drill in sizes 0.5 mm, 0.8 mm, 5.2 mm, and 5.9–13 mm for precision mold drilling

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1. Performance
   • Premium HSS Substrate – Manufactured from cobalt-enriched imported high-speed steel (≈ 6 % Co, 64 ± 1 HRC) that keeps edge hardness above 58 HRC at 600 °C, resisting thermal softening in prolonged dry drilling cycles.
   • Steam-Oxide Surface – Microporous black-oxide conversion layer holds cutting fluid, lowers friction, and evacuates chips cleanly from deep mold cavities; no flaking or dimensional change.
   • Precision Geometry – 118 ° split-point tip with ±0.5 ° grind accuracy delivers true self-centering starts and reduces thrust by up to 30 % versus conventional chisel-point drills. Helix angle 30 ± 1 ° and margin width 0.25 D maintain straight, burr-free walls even in tool steel.
   • Tight Diameter Control – Ground to h8 tolerance (-0 / -12 µm for Ø≤3 mm; -0 / -18 µm for Ø > 3 mm), supporting press-fit dowel or coolant-channel holes without secondary reaming.
2. Application Scenarios & Assembly Requirements
   • Mold & Die Work – Ø0.5–0.8 mm sizes pierce vent holes in injection molds; mid-range Ø5.2 mm opens ejector-pin seats; Ø5.9–13 mm covers coolant circuits and core-pin locations in P20, H13, or SKD61 steels up to 35 HRC.
   • Precision Fabrication – Ideal for drilling stainless fastener holes, hardened bushings, and fixture plates where positional accuracy and surface finish are critical.
   • Machining Guidelines
   – Spindle Run-Out: ≤ 0.01 mm TIR; use ER collet or hydraulic chuck.
   – Cutting Data (P20 steel, emulsion coolant):
   Ø≤1 mm vc = 18 m min⁻¹, f = 0.008 mm rev⁻¹
   Ø5 mm vc = 24 m min⁻¹, f = 0.10 mm rev⁻¹
   Ø10 mm vc = 28 m min⁻¹, f = 0.18 mm rev⁻¹
   – Peck cycle every 3 × Ø for holes deeper than 6 × Ø.
   – Coolant: flood or through-spindle oil-mist for diameters ≥5 mm; air blast acceptable for micro sizes.
3. User-Friendly Operation
   • Self-Starting Split Point – Eliminates center-punching and reduces walking on curved or polished mold surfaces, saving setup time.
   • Unified Shank System – Straight shank equals drill diameter up to 13 mm, compatible with standard DIN 338 holders; no sleeves or special adapters needed.
   • Laser-Etched Identification – Diameter, lot number, and material code permanently marked on shank for quick retrieval and traceability after repeated use.
   • Protective Packaging – Each bit seated in individual, indexed tubes with anti-rust VCI liner; micro sizes supplied in foam-lined cases to prevent chipping.
4. Quality & Longevity
   • ISO 9001 / ISO 14001 Certified Production – In-process CNC vision inspection controls tip symmetry, helix angle, and land width within ±0.01 mm.
   • Extended Tool Life – Comparative endurance tests in 1.2312 steel show up to 2.5 × more holes per re-grind than conventional HSS drills, owing to cobalt enrichment and controlled oxide layer.
   • Re-Sharpenable – Full-length flute grinding and generous web thickness allow multiple regrinds without compromising rigidity; original geometry specification sheet included for accurate restoration.
   • Environmental Compliance – RoHS / REACH approved materials; steam-oxide finish requires no hazardous chrome coatings, ensuring safe disposal and recycling at end of life.