A 30x40x4 mm TC double-lip seal moulded in NBR nitrile rubber: the Oil Seal 30x40x4 NBR TC restores tight sealing on 30 mm shafts and 40 mm bores used in electric motors, gearboxes, pumps and agricultural machinery.
Size and material details
| Inner diameter (shaft) | 30 mm |
| Outer diameter (bore) | 40 mm |
| Width | 4 mm |
| Seal type | TC — double lip, rubber covered, garter spring |
| Material | NBR – Nitrile |
| Temperature range | -30 °C … +100 °C |
Why the TC profile is so widely used
Every TC seal combines three elements: a rubber-covered case that grips the bore, a spring-loaded sealing lip that follows shaft runout, and a dust lip that shields the main lip from contamination.
About the NBR nitrile compound
The compound is NBR nitrile, selected for oil-and-grease compatibility across motors, reducers and pumps. Note the limits: brake fluid degrades nitrile, and sunlight ages stored rubber — so store spares dark and dry.
Don’t worry if your micrometer shows the shaft a few tenths under size — the garter-sprung lip is designed to seal against exactly that condition.
Order details
- Individual pieces, no minimum order — checkout in US dollars.
- Our prices do not cover customs duties or taxes your country may apply; those fall to the buyer.
- One worldwide flat shipping fee · every parcel tracked, number emailed.
- Before you buy, confirm the fit: measuring guide or free dimension check.


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