Another FB Chain speciality is our ability to manufacture high-quality sprocket segments. Split sprocket solutions can save large amounts of downtime when it comes to replacing large, difficult-to-access drives.
| Symptom | Appearance | Probable cause | Correction |
|---|---|---|---|
| Worn contour |  | Abnormal wear rubbing on guides | Replace roller chain when 5% worn. Check roller chain alignment or increase clearance. |
| Pin galling | Inadequate lubrication | Reduce load or roller chain drive speed. Provide proper roller chain lubrication. | |
| Tight joints |  | Dirt or foreign substance packed in joints or corrosion or rust or bent pins | Clean & re-lubricate roller chain. Replace roller chain. |
| Hooked sprocket teeth | Excessive roller chain wear | Replace roller chain and roller chain sprocket. | |
| Abnormal protrusion or turned pins |  | Excessive internal friction caused by high loading and inadequate lubrication | Replace roller chain, improve lubrication and eliminate overload conditions. |
| Cracked plates (fatigue) |  Crack from aperture towards edge of linkplate at 90º to line of pull. Note there is no linkplate distortion. | Loading beyond chain’s dynamic capacity (above fatigue endurance limit) | Replace chain with roller chain of larger dynamic capacity or eliminate high load condition or dynamic (impulse) overloading. |
| Symptom | Appearance | Probable cause | Correction |
|---|---|---|---|
| Fractured plates (tension mode) |  Note material distortion | High overload | Replace roller chain and correct cause of overload. |
| Arc like cracked plates (stress corrosion) |  | Severe rusting or exposure to acidic or caustic medium, plus static pressure at press fit (between pin and pin linkplate). No cyclic stress is necessary for this phenomenon to occur. | Replace roller chain and protect from hostile environment. |
| Enlarged holes |  | High overload | Replace roller chain and correct cause of overload. |
| Corrosion pitting | Exposure to corrosive environment | Replace roller chain and protect from hostile environment. | |
| Broken, cracked or deformed rollers | Speed too high. Sprockets too small | Replace roller chain and reduce speed. Replace roller chain and use larger roller chain sprockets/ | |
| Broken pins | Extreme overload | Replace roller chain. Eliminate cause of overload or redesign roller chain drive/ | |
| Rusted chain | Exposed to moisture. Water in lubricant. Inadequate lubrication | Replace roller chain and protect from moisture. Change roller chain lubricant. Replace roller chain and improve roller chain lubrication. |
