Material specification page for sn500 series split plummer blocks in Cast Iron. Covers the grade designation (grey cast iron EN-GJL-200 / EN-GJL-250 for standard housings; ductile iron EN-GJS where shock or tension is expected), what the material does inside the bearing, its temperature and environmental limits, the alternatives worth considering, and the sizes available to DIN 736 / ISO 113.
Why Cast Iron for SN500 Series Split Plummer Blocks
The housing material for pillow blocks, flange units and plummer blocks — rigid, well damped, and stable enough to hold a round, correctly sized bearing seat after machining. In a sn500 series split plummer blocks it is the housing that carries the bearing and bolts to the machine.
A bearing housing has to be stiff, well damped and dimensionally stable, and it has to hold a round bore after machining and after bolting down. Grey cast iron does all four cheaply, which is why almost every pillow block and plummer block is made of it.
Material Properties
| Grade designation | grey cast iron EN-GJL-200 / EN-GJL-250 for standard housings; ductile iron EN-GJS where shock or tension is expected |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | About -20 °C to +200 °C for a standard grey iron housing |
| Corrosion characteristic | Forms a stable surface oxide indoors; painted or coated for outdoor and washdown service |
Service Limits
Grey cast iron is strong in compression and weak in tension, so it does not like shock or bending — a housing dropped in transit can crack invisibly, and a bolt over-torqued into a cast foot splits it. Where shock is expected, a ductile iron or cast steel housing is the correct part. Outdoors, the surface needs paint or coating.
Alternatives and When to Switch
Ductile iron or cast steel where shock and tension are expected; pressed steel where weight matters more than stiffness; and thermoplastic or stainless housings for washdown and food service, where the failure is corrosion and not load.
Sizes of SN500 Series Split Plummer Blocks Available in Cast Iron
| Designation | For bearing (adapter sleeve) | Shaft diameter range (mm) |
|---|---|---|
| SN505 | 1205K or 2205K (H305) | 20 |
| SN506 | 1206K or 2206K (H306) | 25 |
| SN507 | 1207K or 2207K (H307) | 30 |
| SN508 | 1208K or 2208K (H308) | 35 |
| SN509 | 1209K or 2209K (H309) | 40 |
| SN510 | 1210K or 2210K (H310) | 45 |
| SN511 | 1211K or 2211K (H311) | 50 |
| SN512 | 1212K or 2212K (H312) | 55 |
| SN513 | 1213K or 2213K (H313) | 60 |
| SN515 | 1215K or 2215K (H315) | 65 |
| SN516 | 1216K or 2216K (H316) | 70 |
| SN517 | 1217K or 2217K (H317) | 75 |
| SN518 | 1218K or 2218K (H318) | 80 |
| SN520 | 1220K or 2220K (H320) | 90 |
| SN522 | 1222K or 2222K (H322) | 100 |
| SN524 | 2224K (H3124) | 110 |
