Опис
12B Metric Roller Chain Sprocket — Heavy-Duty Power Transmission for Demanding Environments
The 12B sprocket is the workhorse of heavy-duty ISO metric chain drive systems. Operating at 19.05mm (3/4 inch) pitch, it delivers substantially higher torque capacity than 08B and 10B sprockets, making it the preferred choice for mining conveyor drives, sugar mill machinery, timber processing equipment, and large-scale materials handling across Australian industry. We manufacture 12B sprockets in simplex (12B-1), duplex (12B-2), and triplex (12B-3) with tooth counts from 9 to 114.
Technical Specifications
| Parameter | 12B-1 Simplex | 12B-2 Duplex | 12B-3 Triplex |
|---|---|---|---|
| Pitch | 19.05 mm (3/4″) | 19.05 mm | 19.05 mm |
| Roller Diameter | 12.07 mm | 12.07 mm | 12.07 mm |
| Internal Width | 11.68 mm | 11.68 mm | 11.68 mm |
| Tooth Count Range | 9 – 114T | 9 – 114T | 9 – 114T |
| Tooth Radius (r) | 19 mm | 19 mm | 19 mm |
| Radius Width C | 2 mm | 2 mm | 2 mm |
| Tooth Width B1 | 11.1 mm | 11.1 mm | 11.1 mm |
| Standard | ISO/R 606, DIN 8187 | ISO/R 606 | ISO/R 606 |
12B Sprocket Wear Progression and Replacement Criteria
Understanding when to replace a 12B driven sprocket is critical for preventing chain failure in heavy-duty applications. The table below provides wear stage indicators:
| Wear Stage | Tooth Profile | Action Required | Remaining Life |
|---|---|---|---|
| Stage 1: Normal | Symmetric flanks, no visible wear | Continue monitoring | 100% |
| Stage 2: Moderate | Slight asymmetry, loaded flank shows polishing | Plan replacement at next shutdown | 40-60% |
| Stage 3: Hook | Hook/wave shape on loaded flank, >25% material loss | Replace immediately | 0-10% |
| Stage 4: Critical | Chain rides on tooth tips, skipping under load | Emergency replacement — risk of chain failure | Overdue |
Key Advantages
2.4x
Load capacity vs 08B simplex
HRC 50
Max tooth surface hardness
0.025
mm TIR bore concentricity
3x
Wear life vs unhardened
⚙ Heavy-Gauge Tooth Construction: Wider tooth faces and deeper root profiles than smaller pitch sprockets handle the higher chain tension encountered in mining and heavy industrial drives.
🔥 Induction Hardened to HRC 40-50: Critical for abrasive environments — iron ore dust, coal fines, wood chips, and sugar cane fibre all accelerate tooth wear on unhardened sprockets.
🛠 CNC Precision Manufacturing: Teeth hobbed to AGMA quality class. Bores to H7. Keyways to DIN 6885. Full dimensional inspection before dispatch.
🏭 Material Certification: EN 10204 Type 3.1 available. Satisfies Australian mining AS/NZS ISO 9001 audit requirements and RPEQ project documentation.
✅ Split Sprocket Option: Available in split construction for field replacement without removing the chain. Essential for mining shutdown maintenance.
📈 Multiple Hub Configurations: A-plate, B-hub, C-hub, taper-lock, and QD bushed versions to match your shaft and installation requirements.
Compatibility
| Component | Specification |
|---|---|
| Chain | 12B-1, 12B-2, 12B-3 ISO roller chain (19.05mm pitch) |
| Bore Range | 8mm – 60mm (varies by tooth count) |
| Keyway | DIN 6885 / AS 1403 |
| Not Compatible With | ANSI #60 chain (different roller diameter and internal width despite similar pitch) |
Selection Guide
By Load: 12B simplex handles approximately 2.4x the load of 08B simplex. Select duplex for 1.7x additional capacity, triplex for 2.5x. Consult horsepower rating charts for your operating speed.
By Environment: C45 steel with black oxide for standard indoor. Zinc or zinc-nickel for outdoor. SS316 for marine, chemical, or food-grade. 4140 alloy steel for extreme fatigue and shock loading in mining.
By Maintenance Access: Standard hub for permanent installations. Taper-lock for easy removal. Split sprocket where chain cannot be broken during replacement.
Material and Process
Standard: C45 (1045) carbon steel, 570-700 MPa. High-Fatigue: 4140 alloy steel, 655-900 MPa for mining and heavy shock loads.
Heat Treatment: Induction hardened tooth flanks HRC 40-50 with ductile core. Controlled depth prevents brittle fracture under impact loading.
Surface: Black oxide, zinc, zinc-nickel, hot-dip galvanise, hard chrome, or electro-polish. Selected based on corrosion exposure and industry standards.
Application Scenarios
Mining Conveyor Drives
Primary and secondary conveyor head drives in iron ore, coal, and mineral processing. 4140 steel with induction-hardened teeth for abrasive dust environments. Duplex and triplex for drives exceeding 150 kW.
Sugar Milling & Timber Processing
Cane carrier chains, bagasse conveyors, sawmill log decks, and chip conveyors. SS316 or hard-chrome plated versions for corrosive sugar cane juice exposure.
Customer Reviews
“12B triplex sprockets on our coal handling conveyor head drive. After 14 months tooth wear is under 2%. Outstanding quality compared to previous supplier.”
★★★★★ — Maintenance Superintendent, Hunter Valley, Australia
“We use 12B-2 on our sawmill log deck drives. Split sprocket option saved us significant shutdown time during replacement. Good dimensional accuracy.”
★★★★★ — Mill Manager, Launceston, Australia
“Reliable 12B sprockets for our European-made packaging machinery. Fit was perfect as OEM replacement. Material certification was included.”
★★★★☆ — Technical Director, Dusseldorf, Germany
“We ordered stainless steel 12B for our sugar mill cane carrier. The hard chrome finish is holding up well against the abrasive fibre. Will reorder.”
★★★★★ — Plant Engineer, Mackay, Australia
“Good heavy-duty sprockets for our cement plant conveyor. The 4140 alloy steel option handles the shock loading from irregular feed well.”
★★★★☆ — Reliability Engineer, Mumbai, India
FAQ
Is 12B the same as ANSI #60?
Can I get 4140 alloy steel for mining applications?
Are split 12B sprockets available?
What is the maximum bore for 12B sprockets?
What surface treatment for coastal Queensland sugar mills?
Related Products
12B Roller Chains
Taper-Lock Bushings
Chain Tensioners
Installation
1. Confirm 12B chain pitch (19.05mm). Verify tooth count, bore, and keyway match shaft.
2. Mount sprocket, insert key, torque set screws. For taper-lock: tighten bolts evenly in star pattern.
3. Align drive/driven sprockets within 0.5mm per 300mm centre distance using laser or straightedge.
4. Install chain with 2-3% sag on slack side. For vertical drives, maintain minimum wrap angle of 120 degrees.
5. Lubricate with ISO VG 68-100 oil for operating temperatures above 40C. ISO VG 30-50 below 40C.
Maintenance
Lubricate: Oil at engagement point per schedule. Never use grease on roller chain.
Inspect: Compare tooth profile against new template at each chain change. Check alignment quarterly in vibration-prone environments.
Replace: At hook wear stage (see wear chart above) or if chain skips under load. Target: 2-3 chain lives per sprocket.
Certifications
✅ ISO 9001:2015 ✅ ISO/R 606 ✅ DIN 8187 ✅ EN 10204 Type 3.1 ✅ AS/NZS audit compatible
Why Ever-Power Australia
We are a full-range power transmission manufacturer with 15+ years serving Australian mining, agriculture, and manufacturing. 3,200+ sprocket SKUs, ISO 9001 certified, CNC hobbing and induction hardening capability. We provide 4140 alloy steel sprockets for mining, SS316 for food-grade, and engineering support for sprocket selection. OEM manufacturing with custom bore, surface treatment, and documentation to your requirements.
Request 12B Sprocket Quotation
Provide your 12B specifications including tooth count, bore, material, and quantity.
