Rotary hammer drill bits are core consumables for construction, renovation and infrastructure projects. Straightness directly determines drilling accuracy, service life and construction safety — yet drill bit straightening remains a universal production bottleneck for manufacturers.
Key Straightening Pain Points
- Severe Springback & Secondary Bending Made of quenched & tempered 40Cr/42CrMo steel, drill bits feature asymmetric spiral flutes and special SDS shanks. Heavy residual stress causes re-bending after grinding and carbide tip welding; over-pressing creates invisible micro-cracks that lead to bit breakage under impact. Extra-long bits suffer worse sagging deformation during heat treatment.
- Complicated S-shaped Compound Bending Most bits are not simply arched but twisted in multiple segments. Manual straightening relies on worker experience, with unstable consistency, low efficiency and high labor costs.
- Special Structure Limits Positioning Intermittent spiral grooves damage standard V-block supports; SDS/Four-square shanks create straightening blind zones near the tail. Conventional straighteners lack custom tooling for multi-size bits (Φ4–26mm, 110–550mm).
- Chain Deformation from Multi Processes Deformation accumulates after turning, groove milling, shank extrusion and quenching. Tolerance for runout is only ≤0.2–0.3mm, leaving little room for error.
All-in-One Solutions
- Pre-production Deformation Control (Cost-Effective Prevention)
- Rough straightening of raw bars + natural aging after flute milling to release cutting stress;
- Vertical hanging quenching to avoid gravity bending during heat treatment;
- Optimized process flow: Straightening → Low-temperature stress relief tempering (160–200℃) to eliminate springback fundamentally.
- Intelligent Automatic Straightening Machine (AMS Series Reference)
Custom-built for elongated drill bits with full closed-loop automation: Auto feeding → Servo clamping → High-precision Keyence displacement sensor measuring → AI identification of single/S-shaped bending → Multi-point progressive servo pressing → Re-inspection → Automatic sorting of qualified/NG products.
- Floating arc supports avoid scratching spiral flutes; quick-change SDS shank fixtures for fast size switching;
- 10-inch multilingual touchscreen, PLC control, stores parameters for all bit specs;
- Model AMS-300: Processes Φ3–8mm, 80–300mm bits, Straightness accuracy 0.1mm,12-month warranty
- Post-process Quality Closed-Loop Management
Strict runout inspection after straightening, grinding and welding; regular magnetic particle testing to detect micro-cracks; automatic springback compensation via machine database.
Core Benefits
✅ Boost finished product pass rate by over 90%
✅ Replace 6–8 manual workers, cut labor cost sharply
✅ Eliminate rework & scrapping caused by bending
✅ Compatible with full-range hammer drill bits for mass production
For drill bit manufacturers struggling with unstable straightness and high defect rates, matched pre-deformation control processes + customized automatic straightening equipment are the definitive upgrade solution to win high-end domestic & overseas orders.
The following is the video about the straightening for this drill bit:
More information please visit our straightening machinery website:
www.straighteningmachinery.com
#RotaryHammerBits #DrillBitManufacturing #StraighteningMachine #MetalProcessing #ConstructionTools #IndustrialAutomation