40x55x12 mm Rotary Shaft Oil Seal NBR, Rubber-Covered Single Lip Seal

Product Overview

A 40 x 55 x 12 mm rotary shaft oil seal is pressed into a housing and runs on a rotating shaft, holding oil or grease in and keeping dust and water out. This one has a rubber-covered outer diameter, a nitrile sealing lip loaded by a garter spring, and a 12 mm section.

At a glance:

40x55x12 mm | NBR (nitrile butadiene rubber) | single lip with garter spring, rubber-covered outer diameter | made in Xingtai, Hebei, China | working range -30 C to +100 C (short peaks to +120 C)

VKEFOT builds this size in Xingtai, Hebei, China for distributors and repair programmes that buy by dimension. The 40 mm shaft, 55 mm bore and 12 mm housing width are the three values that set the fit.

Key Features & Benefits

• Rubber-covered body: The rubber outside diameter both seals against the housing bore and grips it, which helps on aluminium housings and on bores that are lightly scored.
• Nitrile lip: NBR holds its sealing force in mineral oil, gear oil and grease and stays flexible down to about -30 C.
• Spring-loaded contact: A garter spring keeps the lip pressed to the shaft as it wears, so sealing does not fade after a few thousand kilometres.
• 12 mm section: The deeper body gives more lip length and a longer sealing path on the shaft than a thin seal of the same bore.
• Selected by dimension: The size is chosen from shaft diameter, bore and width, so a stocked part matches a worn original from stock.
• Workshop friendly: Press in square with a lubricated lip; no special fitting aids are needed and the procedure suits a normal repair bay.

Dimensions & Specification

Specification	Value
Inner Diameter (ID)	40 mm
Outer Diameter (OD)	55 mm
Width / Height	12 mm
Material	NBR (nitrile butadiene rubber)
Colour	Brown
Structure	Single lip, garter spring, rubber-covered outer diameter
Seal Type	Rotary shaft oil seal
Marking	VKEFOT
Continuous Service Temperature	-30 C to +100 C (short peaks to +120 C)
Brand	VKEFOT
Origin	Xingtai, Hebei, China

Dimensions are nominal production values measured as inner diameter x outer diameter x width. Always check them against your own sample or a measured shaft and bore before ordering.

Material & Construction

The lip is NBR (nitrile butadiene rubber) moulded to a metal insert and wrapped in a rubber outer diameter. NBR resists mineral oil, gear oil and grease, works over -30 C to +100 C (short peaks to +120 C), and keeps enough flexibility to follow a shaft that is slightly out of round. A garter spring holds the lip against the shaft. Where the duty is hotter, or the fluid is synthetic or heavily additised, the same size can be quoted in FKM (fluoroelastomer), which handles continuous duty to about +200 C.

Quality Control and Inspection

• Incoming: compound hardness checked before release to production.
• In process: lip geometry, spring seating, rubber-to-insert bond and outer diameter grip checked at set intervals.
• Final: dimensional check on inner diameter, outer diameter and width, hardness, visual inspection of the lip edge and marking, then packing count verification.
• Traceability: inspection results for each batch are recorded and kept; the inspection scope can be agreed before order confirmation.

Third-party inspection before shipment can be arranged on request; state it in the enquiry so it is included in the quotation.

Customization and OEM Service

packaging and logo available upon request

Packaging, Carton and Delivery

Standard packing is individual polybag, inner carton, then export carton. Carton marks, labels and barcodes are printed to buyer specification.

Lead time for standard sizes is typically 7 to 15 working days after order confirmation, and longer for sizes that are not held as standard stock. Minimum order quantity depends on whether the size is a stocked standard or made to order. Pricing, MOQ, freight and trade terms are confirmed in the written quotation. Send an RFQ with quantity and destination port.

How to Order

The more of this you include, the faster and more accurate the quotation:

1. Size or OE number: 40 x 55 x 12 mm, or the number stamped on your current seal.
2. Quantity and destination: required quantity, destination country and port.
3. Material requirement: NBR as standard, or FKM for higher temperature or synthetic fluid.
4. Packaging requirement: carton marks, label data and barcode requirement.
5. Sample photo or drawing: where the part is matched from a worn original.
6. Operating conditions: fluid type, temperature and shaft speed, if known.

Frequently Asked Questions

How do I confirm this seal fits my assembly?
Check the 40 mm shaft, the 55 mm bore and the 12 mm width against the seal being replaced, and look at the lip arrangement and the colour of the rubber. Those points confirm the fit before the seal is pressed in.

What are the exact dimensions of this oil seal?
40 mm inner diameter, 55 mm outer diameter and 12 mm width. Confirm against your own sample or drawing, because housing depth and shaft shoulder position differ between applications.

What is the minimum order quantity?
MOQ depends on whether 40x55x12 is a stocked size or made to order. Tell us the quantity required and we will confirm the MOQ together with tiered pricing.

What is the lead time, and can you ship by sea or air?
Stocked sizes are usually dispatched within 7 to 15 working days after order confirmation. Sea and air shipments are both arranged, with freight and transit confirmed per order.

Can you supply FKM or HNBR instead of NBR?
Yes. This geometry is also available in FKM (fluoroelastomer) or HNBR where continuous temperature or fluid conditions exceed the NBR range. Confirm the compound at the enquiry stage.

Do you provide samples, and are they free?
Samples for evaluation can be arranged. The sample and its freight are quoted per request, and on a confirmed bulk order the sample charge is normally credited against the order.

Can you produce our packaging and logo?
packaging and logo available upon request.

What information do you need to quote?
Size or the number you are replacing, quantity, material, working temperature and fluid, packaging and marking needs, destination port and Incoterm. A drawing or a physical sample gives the best match.

Request a Quotation

Send the 40 x 55 x 12 mm size (or the number on the seal you are replacing), quantity, destination and any branding requirement, and we will come back with MOQ, lead time, packing details and pricing.

VKEFOT Seals: oil seals, O-rings and custom rubber parts. Xingtai, Hebei, China.