Wear-Resistant 20CrMnTi High-Head Sewing Machine Gear Set for Leather Goods Production

Wear-Resistant 20CrMnTi High-Head Sewing Machine Gear Set for Leather Goods Production

High-head sewing machine gears are heavy-duty core transmission parts for high-head sewing machines (8B/341/246/ big/small mouth high-head), including lower shaft spur gears, hook helical gears, bevel gears, eccentric gears, feed gears and gear sets. They fit high-column machines for thick materials and tubular sewing in limited spaces. Made of 40Cr/42CrMo/20CrMnTi high-strength alloy steel with quenching & tempering + induction/carburizing hardening, they feature high torque, impact resistance, wear resistance, compact space adaptation and low noise. They transmit power for the main shaft, lower shaft, hook, feed dog, thread take-up and presser foot lift, ensuring tight stitches, precise hook synchronization, no thread breakage and heavy-load resistance in leather/thick material tubular sewing. They are key vulnerable parts for luggage, shoes and leather goods.

Product Features

• High-torque heavy-duty: Module 1.25–2.5mm, thickened tooth root and widened tooth width withstand 80–180N·m torque without chipping or deformation on thick leather.
• Compact space adaptation: Thin hub and short tooth design fit the narrow head/lower shaft cavity of high-head machines without installation interference.
• Precise hook synchronization: Helical + eccentric gear combination ensures hook synchronization error ≤±0.1mm, preventing thread breakage and ensuring neat stitches on thick materials.
• Impact & fatigue resistance: No tooth breakage during frequent start/stop/thick material impact (≤1800 times/day) for stable continuous leather production.
• Wear resistance & long life: Tooth surface HRC 52–60 resists leather dust/oil wear for ≥7000 hours service life.
• Quiet transmission: ISO Grade 7 precision and polished surfaces ensure 0.08–0.18mm meshing clearance, noise ≤68dB and quiet head operation.
• Strong interchangeability: Fits Juki 341, Seiko 8B, Hailin 246, Jinling 8BL and domestic high-head machines for easy replacement.
• Auto-lubrication compatible: Narrow oil grooves + self-lubricating tooth profile suit top/side oil supply with high resistance to low-oil/dry running.

Technical Parameter Table

 Main Applications

• Lower shaft + hook gear sets for 8B/8BL/341/246 high-head machines (core components).
• Drive gears for main shaft transmission and feeding mechanisms in big/small mouth high-head machines.
• Tubular thick material sewing equipment for leather goods, shoes, luggage and gloves.
• Transmission parts for high-head machines sewing 3–12mm thick materials like leather/PU/canvas/synthetic leather.
• Gear parts for automatic thread trimming, presser foot lift and reverse stitching mechanisms.
• Complete transmission gears for high-head machines in tanneries, leather goods factories and shoe factories.
• Replacement gears for old high-head machines (Juki, Seiko, Hailin, etc.).

 Product Advantages

• High torque & anti-chipping: Thickened tooth roots + heavy-duty material withstand high thick leather tension without fracture.
• Precise hook synchronization: Helical + eccentric gear combination ensures secure thick material locking, no breakage and neat stitches.
• Strong space adaptation: Thin short tooth design fits narrow head/lower shaft cavity without installation interference.
• Wear resistance & long life: HRC 52–60 tooth surfaces resist leather dust abrasion, reducing downtime for replacement.
• Efficient & quiet transmission: Precise meshing + polishing reduce noise and vibration for stable head operation.
• Wide thick material adaptation: Fits 3–12mm leather/PU/canvas, covering leather goods/shoes/luggage processing.
• Easy maintenance: Standard specifications and strong interchangeability enable quick installation and replacement in narrow high-head spaces.
• Cost-effective: Mass production with stable quality reduces equipment operation and maintenance costs for leather goods factories.

Production Process

• Raw material inspection: 40Cr/42CrMo/20CrMnTi checked for composition, hardness and defects.
• Cutting & forging: Steel cutting → hot forging to enhance tooth root rigidity (critical for hook gears).
• Pre-heat treatment: Normalizing eliminates forging stress and improves machinability.
• CNC finish turning: Precision turning of gear blank OD, ID and end face ensures concentricity and runout.
• Gear hobbing/milling: Specialized machines process tooth profiles (spiral teeth for hook helical gears).
• Chamfering & deburring: Tooth end chamfering and polishing reduce noise and scratching.
• Quenching & tempering: Overall tempering (HRC 28–35) improves toughness and impact resistance.
• Tooth surface hardening: Induction hardening (spur gears) or carburizing hardening (hook/heavy-duty gears) to HRC 52–60.
• Precision grinding: ID, journal and tooth surface grinding ensures fitting accuracy and smooth meshing.
• Meshing matching: Gear set pairing (especially hook helical + lower shaft spur gears) ensures uniform clearance and quiet operation.
• Surface treatment: Blackening/phosphating + anti-rust oil for oil, moisture and dust resistance.
• Full inspection & warehousing: Comprehensive check of dimensions, hardness, meshing precision, hook synchronization and appearance before packaging.

Why Choose us?

• 7-axis CNC Grinding: We adopt high-precision 7-axis CNC grinding machines, holding tolerances as tight as ±5μm, ensuring gears run quietly, smoothly and with outstanding durability.
• Strong technical expertise: Our core R&D team includes doctoral and master’s professionals specializing in spiral bevel gear technology, providing strong technical support for complex projects.
• Rigorous testing & high precision: All gears undergo 100% inspection with Gleason metrology systems. We can achieve DIN 6 grade accuracy with strict control over tooth profile and direction errors, keeping our quality at the industry-leading level.
• High transmission efficiency: Our gear designs support a single-stage reduction ratio of up to 300:1, with actual transmission efficiency reaching over 95%, greatly improving energy utilization.
• Excellent durability & cost efficiency: Our gears deliver 40% lower lifecycle cost and a failure rate below 0.5%, ensuring stable long-term operation and reduced maintenance costs.
• Fast response & short lead time: Supported by our digitalized production process, we are able to shorten the delivery cycle to only 20 working days, helping you accelerate project development and launch.
• Professional custom design capability: We provide fully customized gear solutions for applications requiring high-reduction, high-speed, heavy-load, low-noise, and special small-tooth profiles, based on your actual working conditions.