CEMA C Idler – Imperial Specification (US Customary Units)
CEMA C Idlers are designed for medium to heavy-duty belt conveyor applications operating under continuous loads. Manufactured as per Conveyor Equipment Manufacturers Association (CEMA) standards, they are widely specified by EPC contractors, OEMs, and mine operators across North America and global export projects.
What Defines a CEMA C Idler (Imperial Context)
CEMA C represents a higher load rating and structural robustness than CEMA B, suitable for conveyors with:
Higher belt tensions
Larger lump sizes
Longer center distances
24/7 operating cycles
It is typically the baseline duty class for mining and heavy industrial conveyors.
Key Engineering Features
Heavy-wall steel roller shells for impact and fatigue resistance
Precision-turned steel shafts to control deflection under load
Premium deep-groove ball bearings (L10 life optimized)
Multi-stage labyrinth seals to block dust, water, and fines
Low rolling resistance for reduced conveyor power demand
Dynamic balancing for smooth operation at higher belt speeds
Available Idler Types
Troughing Idlers – 20°, 35°, 45° trough angles
Return Idlers – Flat return or V-return
Impact Idlers – Rubber disc or HDPE disc (loading zones)
Training Idlers – Self-aligning types
Special / Garland Idlers – On request
Typical Imperial Technical Range
| Parameter | CEMA C (Imperial) |
|---|
| Belt Width | 18 in to 72 in |
| Roller Diameter | 5 in, 6 in |
| Shell Thickness | 0.157 in – 0.197 in |
| Shaft Diameter | 1 in – 1.25 in |
| Belt Speed | Up to ~1000 FPM |
| Duty Class | Medium to Heavy |
(Final sizing depends on belt tension, material density, idler spacing, and impact loading.)
Industries & Applications
Surface & underground mining conveyors
Cement plants (raw material & clinker handling)
Aggregate & crushing systems
Coal handling systems in power plants
Steel mills & bulk terminals
Why Specify CEMA C Idlers
Longer bearing and roller life vs light-duty idlers
Lower total cost of ownership (TCO)
Reduced belt wear and misalignment issues
Globally accepted standard for EPC and OEM projects
Engineering Buyer Note
For conveyors operating >20 hours/day, belt widths ≥36 in, or material bulk density above 80 lb/ft³, CEMA C idlers should be treated as the minimum safe design class. Using lower-class idlers often results in early bearing failure, higher power consumption, and unplanned shutdowns.
