1245 Heavy Duty Offset Cranked Link Chain

1245 Heavy Duty Offset Cranked Link Chain adopts a single-side cranked offset link structure, specially engineered for ultra-heavy loads, shock impact, and dusty, harsh working conditions, supporting both medium-speed power transmission and long-distance material traction conveying. It is widely deployed in mining, construction machinery, and metallurgy heavy drive systems. Different from standard straight roller chains, this model uses uniform cranked links without inner/outer link separation, enabling easier cutting, lengthening, disassembly, and maintenance. Matching customized 1245 sprockets with variable hub, bore, and tooth quantity are fully available for supporting installation.

Structural Composition

The 1245 chain adopts an integrated offset cranked link design with a uniform single-link structure, consisting of 5 core components for every unit link:

1. Offset Sidebar: Thickened alloy steel plate with single-side bend, the main load-bearing frame; thickness 0.56 in (14.5mm), height 2.38 in (60mm), cranked profile absorbs impact shock loads.

2. Pin: Full-round or K-type press-fit pin, locked tightly into sidebars to eliminate pin rotation. It penetrates bushings, rollers, and two sidebars to bear tensile and shear forces.

3. Bushing: Case-hardened alloy steel sleeve fitted over pins, forming a friction pair with rollers to absorb impact and cut wear loss.

4. Roller: Heat-treated alloy steel wheel rolling against sprocket teeth, distributing meshing impact and reducing tooth abrasion.

5. Cotter Pin: Locking accessory installed on pin ends to prevent pin separation. Damaged single links can be replaced partially without full chain disassembly.

Material & Manufacturing Feature

Core Component Materials

• 1. Offset Sidebar: Premium alloy with high toughness and fatigue resistance; overall quenching & tempering to boost structural strength.

2. Pin: Alloy structural steel, fully tempered + surface induction hardening, balancing core toughness and surface hardness to resist shear and abrasion.

3. Bushing: Carburizing alloy steel, hard surface layer with tough core to avoid cracking under heavy impact.

4. Roller: Medium carbon steel full quenching, wear-resistant surface with shock-absorbing inner core.

Key Manufacturing Processes

1. Hot Forging & Extrusion Punching for Sidebars: High-temperature hot forming, pitch holes processed by extrusion punching to expand contact area between pin and sidebar, preventing loose rotation during operation.

2. Graded Heat Treatment for All Parts: Separate tempering for sidebars, induction hardening for pins, carburizing for bushings, full quenching for rollers; differentiated thermal treatment matches force load characteristics of each component.

3. Press-Fit Pin Lock Technology: High-pressure interference fit locks pins firmly into offset sidebars, eliminating pin rotation and cutting internal friction loss.

4. Shot Peening Strengthening: All stamped components are shot peened to release internal residual stress and extend anti-fatigue service life significantly.

5. Surface Anti-Corrosion Finishing: Standard version high-temperature black oxide coating; export grade Dacromet / galvanized coating for rust and dust resistance.

Advantages

1. Superior Tensile & Impact Strength

• Ultra-High Ultimate Tensile Capacity: Base model SS1245F1 reaches ultimate tensile strength of 530kN, providing abundant safety margin and ultra-low breaking risk; F3 reinforced variant boosts tensile strength up to 722kN for ten-thousand-ton heavy traction machinery.

• Cranked Link Shock Absorbing Design: Integrated single-side bent sidebars deliver an elastic deformation buffer to absorb instant impact loads from equipment startup, shutdown, and material collision, solving frequent breaking issues of straight standard chains; ideal for intermittent shock transmission.

•  Heavy Shear-Resistant Pin Construction: Oversized 25.6mm diameter interference-fit pins with anti-rotation lock, lateral shear resistance improved by 60% vs same-size standard roller chains, eliminating pin shear failure.

2. Outstanding Wear Resistance

• Large-Diameter Low Specific Pressure Friction Design: A 45.2mm oversized roller expands the contact area with the sprocket teeth, reducing meshing abrasion and extending the full drive system service life.

• Ample Lubricant Storage Clearance: Reserved grease storage cavity between pins, bushings, and rollers slows grease loss in dusty environments, and maintenance lubrication intervals are extended.

3. Flexible Design & Custom Process

• Universal Offset Link for Flexible Modification & Maintenance: No separate inner/outer links; the chain can be cut or lengthened at any position; only a damaged single link needs replacement instead of full chain scrap, greatly cutting maintenance cost. Conventional straight roller chains require paired inner/outer link replacement with rigid modification limits.

• Optional Multi Anti-Corrosion Coating Processes: Four surface treatment options – standard black oxide, export-grade Dacromet, hot-dip galvanizing, partial stainless steel modification – matching dry dusty, coastal humid and mild chemical corrosion working environments respectively.

• Custom Length & Graded Strength Options: Factory cutting to any required chain length as per client order; F1/F2/F3/F4 graded strength variants fully cover equipment from light construction machinery to ten-thousand-ton port heavy load systems.

• Integrated Matching Sprocket Customization: Custom 1245 sprockets supplied synchronously with variable hub, bore, tooth count, and tooth surface hardening treatment for one-stop complete set delivery, ideal for foreign trade bulk orders.

Application Fields

1. Mining & Quarry Industry: Ore hoist, crusher power drive, long-distance gravel scraper conveyor, enduring heavy ore impact and abrasive dust wear.

2. Construction Machinery: Heavy excavators, loaders, asphalt mixing plants, concrete mixer main drive; suitable for frequent start-stop shock load conditions.

3. Metallurgy & Steel Mill: Hot rolling line, sintering machine, steel waste conveying chains; F3 high-strength variants for combined high temperature & heavy load harsh environments.

4. Port Logistics Equipment: Bulk cargo handling traction machines, stacker-reclaimer conveying chains for all-weather outdoor heavy-duty operation.

5. Heavy Agricultural Machinery: Large grain harvesters, palm oil press production line material traction drive.

6. Building Material & Solid Waste Treatment: Cement kiln auxiliary drives, geomembrane traction conveyors for landfill projects, stone crushing transport systems.

Common Variant Models

Multiple variants are derived from the base 1245 model, differentiated by prefix codes for manufacturing process, attachments, and anti-corrosion grades; mainstream export models as below:

1. SS1245F1 (Standard Base Version): General industrial standard model with full-component heat treatment, no extra attachments, widely used in mining & construction power transmission, mass-produced by domestic chain factories.

2. RO1245T / US1245 (EU & US Export Standard): ASME-compliant heavy-duty variant with reinforced press-fit pins and heavy-duty cotter locks, specially designed for overseas construction machinery and heavy conveyors export orders.

3. SS1245F2/F3/F4 (Thickened & Widened Custom Variants)

• F2: Widened heavy-duty model. Its inner sidebar clearance is 2.4 mm wider than that of SS1245F1, with increased unit weight.

• F3: Ultra-high tensile strength model, featuring upgraded ultimate tensile strength compared with SS1245F1.

• F4: Lightweight cost-effective model. Its inner sidebar clearance is 0.3 mm narrower than SS1245F1, delivering lower unit weight.