EN
Published by: Technical Editorial Team, Tianjin HaoRongShengYe (tjhrsy.com) / KDI Transmission
Target Audience: Global Mechanical Engineers, Procurement Managers, Industrial Distributors, and OEM Machinery Builders
In high-load mechanical power transmission and conveyor systems, the pin is the backbone of the chain. It bears full shear forces, cyclic bending moments, and intense wear during high-speed engagement with sprockets. A chain pin’s reliability directly governs the fatigue life and operational safety of entire production lines. This article breaks down the complete, step-by-step manufacturing process of high-precision industrial chain pins, aligned with international ISO, ANSI, and DIN standards.
The manufacturing process begins with structural alloy and carbon steel wires or rods. Standard material grades include 20CrMnTi, 8620 (20CrNiMo), 40Cr (AISI 5140), and S55C.
● Optical Emission Spectrometry (OES): Verification of chemical composition (Carbon, Chromium, Nickel, Molybdenum) for every steel batch.
● Inclusion & Microstructure Check: Non-metallic inclusion evaluation to prevent micro-fissures during cold forming or heat treatment.
High-speed automatic cold heading machines are utilized to form the initial pin blanks without cutting steel fibers, preserving the material’s grain flow and enhancing fatigue strength.
● High-Speed Shearing: Cutting raw wire rods to precise length blanks with minimal burr formation.
● Cold Forging / Heading: Forming pin heads or specialized retaining grooves while maintaining material grain continuity.
Secondary CNC machining processes refine the geometrical profile of the pin to match strict drawing specifications.
● End Chamfering: Adding precise lead-in chamfers to facilitate smooth press-fitting into chain inner and outer link plates without galling.
● Grooving & Cotter Holes: Turning circlip grooves or drilling cross-holes for cotter pin type chains (ANSI heavy-duty series).
Heat treatment is the core phase that determines a pin's wear resistance and shock load strength.
| Process Step | Operational Parameters | Target Mechanical Property |
| Continuous Carburizing | 900°C – 930°C in endothermic atmosphere | Controlled carbon diffusion into the surface layer |
| Oil Quenching | Controlled oil temperature & agitation | Martensitic transformation for surface hardness |
| Low-Temperature Tempering | 180°C – 220°C for stress relief | Elimination of internal stresses and micro-fracture risks |
After heat treatment, pins undergo centerless grinding to restore exact dimensional tolerances and achieve mirror-like surface smoothness.
● Multi-Pass Centerless Grinding: Achieves outer diameter tolerances up to h8 / h9 (IT7–IT8 precision).
● Surface Roughness Control: Reduces surface roughness to Ra ≤ 0.4 μm, minimizing initial break-in wear and dry friction.
● Vibratory Polishing / Shot Peening: Enhances surface compressive stress to boost dynamic fatigue limit.
| Quality Parameter | Standard Target Value | Testing Equipment |
| Surface Hardness | HRC 58 – 62 (HV 650 – 750) | Rockwell / Vickers Hardness Tester |
| Core Hardness | HRC 32 – 40 | Sectional Vickers Hardness Tester |
| Effective Case Depth | 0.5 mm – 1.5 mm (Pitch Dependent) | Microhardness Gradient Profiler |
| Micro-Crack Inspection | Zero surface / subsurface cracks | Magnetic Particle Inspection (MPI) |
| Dimensional Consistency | Cylindricity & Roundness < 0.005 mm | Air Gauge / CMM / Optical Comparator |
Video Details
● Title: How Industrial Chain Pins Are Manufactured: Precision Heat Treatment & Quality Control
● Target Audience: Global Transmission Engineers, B2B Procurement Teams, Industrial Machinery OEM Buyers
Scene-by-Scene Script
[SCENE 1: OPENING HOOK - 0:00 - 0:15]
Visual: Dynamic shot of heavy-duty conveyor chain operating under extreme load, followed by a sudden macro close-up of a high-precision ground chain pin.
Voiceover: "In an industrial transmission chain, a single pin must withstand millions of stress cycles and tons of shear load. Ever wondered how these critical components are manufactured to survive extreme wear and prevent catastrophic fatigue failures?"
[SCENE 2: RAW MATERIAL & COLD HEADING - 0:15 - 0:45]
Visual: Automated coil feeding into high-speed cold heading machine. Precision blank cutting in slow motion.
Voiceover: "It all starts with certified alloy steel wire rods like 20CrMnTi or 8620. Through continuous cold heading, the steel fibers remain unbroken, providing superior structural integrity compared to standard machining."
[SCENE 3: CARBURIZING HEAT TREATMENT - 0:45 - 1:15]
Visual: Red-hot pins emerging from a continuous furnace into an oil quenching bath, followed by microhardness depth testing in a laboratory.
Voiceover: "The core secret to durability lies in heat treatment. Our continuous carburizing process infuses carbon into the surface layer, achieving a glass-hard surface of HRC 58 to 62 for wear resistance, while keeping a tough HRC 32 to 40 core to absorb severe shock loads."
[SCENE 4: CENTERLESS GRINDING & INSPECTION - 1:15 - 1:45]
Visual: High-precision centerless grinding with coolant flow; CMM measurement and Magnetic Particle Inspection (MPI) under UV light.
Voiceover: "Finally, centerless grinding achieves h8 diameter tolerances and a Ra 0.4 surface finish. Combined with 100% Magnetic Particle Inspection for zero cracks, every pin is guaranteed ready for global industrial applications."
[SCENE 5: CALL TO ACTION - 1:45 - 2:00]
Visual: Finished roller chain assembly and Tianjin HaoRongShengYe / KDI brand logo with website link.
Voiceover: "For custom OEM chains, sprockets, and precision transmission parts built to ISO and ANSI standards, visit www.tjhrsy.com or contact our engineering team today."
For detailed engineering consultations, technical drawings, or quotation requests regarding chains, sprockets, gears, and racks, visit www.tjhrsy.com.
