En fabricación industrial, ¿Por qué? 98% of high-quality screw producers rely on CNC machine tool processing screws instead of traditional manual lathes? La respuesta radica en la capacidad del CNC para resolver puntos críticos, como dimensiones de rosca inconsistentes., ciclos de producción lentos, y altas tasas de desperdicio, que afectan a los métodos manuales. Este artículo desglosa el flujo de trabajo completo., parámetros clave, selección de herramientas, control de calidad, and real-world applications of CNC screw processing, helping you achieve uniform, eficiente, and cost-effective screw production.
What Is CNC Machine Tool Processing Screws?
Tornillos de procesamiento de máquinas herramienta CNC is an automated manufacturing process that uses Computer Numerical Control (CNC) lathes or machining centers to produce screws—critical fasteners used in machinery, electrónica, and construction. Unlike manual processing (where operators manually adjust tool positions and cutting speeds), CNC systems follow pre-programmed G-code and M-code to control every step: from shaping the screw’s outer diameter to cutting precise threads.
Think of it as a “digital craftsman” for screws: it executes repetitive tasks with micron-level accuracy, ensuring every screw matches design specs (p.ej., thread pitch, head shape) perfectly—even for high-volume production runs of 10,000+ unidades.
Full Workflow of CNC Machine Tool Processing Screws
CNC screw processing follows a linear, error-proof sequence—each step builds on the last to avoid defects. Below is the detailed workflow with actionable tips:
- Preparación de materiales
- Meta: Select raw materials that match the screw’s strength and corrosion resistance needs.
- Materiales comunes:
- Carbon steel (for general-purpose screws, p.ej., DE 933 pernos).
- Acero inoxidable (304/316, for corrosion-resistant screws in medical/ marine applications).
- aleación de titanio (for high-strength screws in aerospace).
- Form: Use metal bar stock (diameter 3mm–50mm) or wire—bar stock is ideal for thick screws, while wire suits thin, small screws.
- Tip: Dry materials at 80°C for 2 hours if stored in humid environments—moisture causes surface rust during machining.
- Clamping & Posicionamiento
- Proceso: Secure the raw material to the CNC lathe’s spindle chuck or collet.
- Accuracy Requirement: Use a dial indicator to check runout (radial deviation) < 0.01mm—excess runout leads to uneven thread depth.
- Solution for Long Materials: For bar stock longer than 300mm, use a tailstock center to support the free end (prevents bending during rotation).
- Selección de herramientas
The right tool determines thread quality and tool life. Use this table to match tools to screw types:
| Screw Feature | Recommended Tool Type | Ventaja clave |
| Outer circle turning | Carbide turning inserts (CCMT 09T304) | Alta resistencia al desgaste; handles cutting speeds up to 200 m/min for steel. |
| Thread cutting (externo) | Indexable threading inserts (16IR 1.5 ISO) | Quick tool change; uniform thread profile (60° included angle for metric screws). |
| Screw head shaping | Acero de alta velocidad (HSS) fresas finales | Sharp cutting edge; ideal for shaping hexagon or pan heads. |
- Programación CNC
- Core Codes:
- G76: Thread cutting cycle (sets pitch, profundidad, and number of passes).
- G01: Linear interpolation (moves tool to thread start position).
- M03: Spindle rotation (clockwise for right-hand threads).
- Example Program Snippet for M5×0.8mm Screw:
G00 X7 Z5; (Position tool above material)G76 P020060 Q0.005 R0.01; (Set thread quality: 2 passes, 60° angle, 0.005mm minimum cut)G76 X4.2 Z-15 P0.583 Q0.3 F0.8; (Cut thread: minor diameter 4.2mm, length 15mm, pitch 0.8mm)- Tool for Complex Screws: Use CAD/CAM software (p.ej., cámara maestra) to generate programs for screws with non-standard threads (p.ej., trapezoidal threads for lead screws).
- Simulación & Trial Machining
- Simulación: Use the CNC system’s virtual simulation function to check for tool collisions (p.ej., tool hitting chuck) or overcuts (excessive material removal).
- Trial Run: Machine 1–2 test screws first. Inspect:
- Thread pitch (use a thread gauge).
- Outer diameter (use a micrometer).
- Head flatness (use a surface plate and feeler gauge).
- Adjustment: If thread depth is 0.05mm too shallow, increase the “P” value in G76 by 0.05mm.
- Formal Machining
- Parámetros de corte: Optimize based on material (ver la tabla a continuación):
| Material | Cutting Speed (m/mi) | Tasa de alimentación (mm/vuelta) | Depth of Cut per Pass (milímetros) |
| Acero carbono (45#) | 150–180 | 0.15–0.2 | 0.2–0,3 |
| Acero inoxidable (304) | 80–120 | 0.1–0.15 | 0.15–0.25 |
| Aleación de titanio (Ti-6Al-4V) | 50–80 | 0.08–0.12 | 0.1–0.2 |
- Escucha: Listen for abnormal noises (p.ej., squealing = tool wear) — replace tools if wear exceeds 0.1mm.
- Inspección de calidad
- Key Metrics & Herramientas:
- Thread pitch: Thread plug gauge (para roscas internas) or ring gauge (para roscas externas).
- Precisión dimensional: Máquina de medición de coordenadas (MMC) — tolerance ±0.02mm for critical screws.
- Rugosidad de la superficie: Profilometer — Ra < 1.6 μm for visible screws; Real academia de bellas artes < 0.8 μm for precision machinery screws.
- Sampling Rate: Inspect 5% of screws for small batches (100–500 unidades); 1% for large batches (10,000+ unidades).
- Post-Treatment
- Desbarbado: Use a nylon brush or tumbler (10 minutos) to remove burrs on thread roots (prevents hand injury during assembly).
- Tratamiento superficial:
- Zinc plating (for carbon steel screws — improves corrosion resistance).
- Pasivación (for stainless steel — enhances surface oxide layer).
- Tratamiento térmico: For high-strength screws, quench and temper at 850°C (increases tensile strength to 800 MPa+).
CNC vs. Traditional Screw Processing: A Critical Comparison
Why switch to CNC? The table below highlights the gap in efficiency and quality:
| Aspecto | CNC Machine Tool Processing | Traditional Manual Lathe |
| Production Speed | 30–50 screws per hour (M5 size). | 8–12 screws per hour (M5 size). |
| Thread Accuracy | Pitch tolerance ±0.005mm; 99.5% consistencia. | Pitch tolerance ±0.05mm; 85% consistencia. |
| Tasa de chatarra | <1% (simulación + trial run reduce errors). | 8–12% (operator error, desgaste de herramientas). |
| Labor Requirement | 1 operator manages 2–3 CNC lathes. | 1 operator per lathe (full-time supervision). |
Real-World Application Case: Aerospace Screw Manufacturing
- Desafío: An aerospace firm needed titanium alloy screws (M8×1.25mm) con:
- Tensile strength > 900 MPa.
- Thread tolerance class 4h (strict for aircraft engine mounting).
- Corrosion resistance to jet fuel.
- CNC Solution:
- Material: Titanium alloy Ti-6Al-4V bar stock (diameter 10mm).
- Herramientas: Carbide threading inserts (16IR 1.25 ISO) with TiAlN coating (resists high heat).
- Parameters: Cutting speed 60 m/mi, feed rate 0.1mm/rev, 8 thread passes.
- Post-treatment: Pasivación + tratamiento térmico (900°C quenching).
- Resultado:
- Scrap rate dropped from 15% (tradicional) a 0.8%.
- Production time per 1000 screws cut from 83 horas para 20 horas.
- All screws passed aerospace industry testing (ASTM F568M standard).
La perspectiva de la tecnología Yigu
En Yigu Tecnología, we see CNC machine tool processing screws as the foundation of reliable industrial fastening. Our CNC lathes (YG-2000 series) are optimized for screw production: they have auto-tool change systems (cut tool change time by 60%) and real-time thread quality monitoring (alerts for pitch deviations > 0.003milímetros). We’ve helped automotive clients cut screw production costs by 35% and aerospace firms achieve 4h thread tolerance consistently. As demand for micro-screws (M1–M3) grows, we’re integrating high-precision spindles (runout < 0.005milímetros) to support next-gen electronics manufacturing.
Preguntas frecuentes
- q: What’s the minimum screw size CNC machines can process?
A: Our standard CNC lathes handle screws as small as M1×0.25mm (diameter 1mm, pitch 0.25mm). For micro-screws (M0.5×0.1mm), we offer custom machines with ultra-fine collets (0.5mm de diámetro) and high-frequency spindles (40,000 RPM).
- q: How to reduce tool wear when processing stainless steel screws?
A: Use tools with TiAlN or diamond coatings (increase wear resistance by 2x). Also, apply cutting fluid (water-soluble for 304 acero) to reduce friction—fluid flow rate should be > 5 L/min.
- q: Can CNC process both metric and imperial screws?
A: Sí! Our CNC systems support both metric (ISO) and imperial (UNC/UNF) thread standards. Just input the thread pitch (p.ej., 0.8mm for metric M5, 0.0315” for imperial #10-32) in the G76 cycle—no hardware changes needed.