High-Strength Blade & Knife Bolts

Premium 41Cr4 alloy steel bolts with Grade 10.9 and 12.9 ratings, hardened to 39-44 HRC for cutting machinery and agricultural equipment. Available with standard nuts, washer nuts, and nylock nuts.

Strength Grades Comparison

Two premium strength grades designed for different load requirements and cutting machinery applications.

Grade 10.9

Grade 10.9 Bolts

Medium-high strength rating suitable for standard agricultural cutting equipment and moderate impact applications.

Specifications

  • Tensile Strength: 1000 MPa
  • Yield Strength: 900 MPa
  • Material: 41Cr4 alloy steel
  • Hardness: 39-42 HRC
  • Thread Standards: M6 to M36
  • Heat-treated and tempered

Best For

  • Agricultural harvesters and mowers
  • Standard cutting equipment
  • Moderate impact applications
  • Cost-effective solution
  • Reliable performance in normal conditions
Grade 12.9

Grade 12.9 Bolts

Ultra-high strength rating for demanding cutting machinery and applications requiring maximum impact resistance.

Specifications

  • Tensile Strength: 1200 MPa
  • Yield Strength: 1080 MPa
  • Material: 41Cr4 alloy steel
  • Hardness: 42-44 HRC
  • Thread Standards: M6 to M36
  • Premium heat treatment process

Best For

  • High-impact cutting machinery
  • Heavy-duty agricultural equipment
  • Severe vibration environments
  • Critical fastening applications
  • Extreme operating conditions

Material & Hardness Details

Professional-grade 41Cr4 alloy steel with precise hardness control for superior strength and durability.

41Cr4 Alloy Steel Properties

41Cr4 is a premium alloy steel specifically designed for high-strength fastener applications requiring excellent toughness and fatigue resistance.

  • Chromium and molybdenum alloying
  • Superior fatigue resistance
  • Excellent impact toughness
  • Low crack sensitivity
  • Outstanding machinability
  • Precise composition control

Hardness & Heat Treatment

Our bolts undergo rigorous heat treatment processes ensuring consistent hardness within specified ranges for reliable performance.

  • Heat-treating to achieve specified hardness
  • 39-44 HRC hardness range
  • Hardness verified by certified testing
  • Hardness uniformity across batch
  • Tempered for reduced brittleness
  • 100% hardness verification available

Technical Specifications

Property Grade 10.9 Grade 12.9
Material 41Cr4 Alloy Steel 41Cr4 Alloy Steel
Tensile Strength 1000 MPa minimum 1200 MPa minimum
Yield Strength 900 MPa minimum 1080 MPa minimum
Hardness (HRC) 39-42 HRC 42-44 HRC
Elongation ≥ 9% ≥ 8%
Thread Range M6 to M36 M6 to M36

Assembly Options

Flexible nut combinations to match your specific assembly and vibration resistance requirements.

Standard Nuts

Plain hex nuts providing basic fastening. Suitable for static applications or where vibration is minimal. Most economical option for standard installations.

Washer Nuts

Nuts with integral washer providing increased bearing surface. Ideal for applications with delicate surfaces or where load distribution is required.

Nylock (Nylon Insert) Nuts

Self-locking nuts with nylon insert preventing vibration loosening. Recommended for dynamic applications and machinery subject to continuous vibration and movement.

Applications & Key Benefits

Purpose-built for demanding agricultural and industrial cutting machinery applications.

Agricultural Harvesting Equipment

Blade bolts for combine harvesters, forage choppers, and hay balers where cutting blades experience extreme loads and impact forces.

Cutting & Mulching Machinery

Precision fastening for blade assemblies in rotary cutters, brush mowers, and industrial shredders operating at high RPM.

Forestry Equipment

Critical fasteners for wood chippers, log splitters, and sawmill equipment where cutting forces are severe and unpredictable.

Construction Machinery

Blade bolts for excavator buckets, trenching equipment, and soil preparation machinery requiring extreme holding strength.

Impact & Vibration Resistance

41Cr4 alloy composition provides exceptional fatigue strength and vibration damping for continuous-duty applications.

Cost-Effective Performance

Premium strength at competitive pricing, offering excellent value for demanding agricultural and industrial applications.

Ready to Source Premium Blade Bolts?

Contact our sales team to discuss your specific requirements, strength grade selection, nut configurations, and bulk pricing for agricultural or industrial applications.

Request a Quotation
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