1. Start with the medium and the contamination risk

According to the supplier's product information, these seals are used in automobile engines and geared motors. Their main purpose is to prevent oil leaking from the end of a rotating shaft and to stop dust getting in from outside. The same source says they can also prevent the leakage of water, chemicals and gas, and keep out dust, soil and sand.

When you write a request, state:

• What is being sealed: engine oil, gear lubricant, water, a chemical or a gas.
• What must be kept out: dust, soil, sand or water from outside.
• Where the part goes: for example, the front or rear of the crankshaft.

The medium drives the choice of rubber compound. In its FAQ, the supplier lists these production materials: NBR, EPDM, silicone, FKM, neoprene (CR), NR, IIR, SBR, ACM, AEM, fluorosilicone (FVMQ) and FFKM. The listings do not say which compound suits which medium or temperature. Give the supplier your medium and conditions and ask for a written material recommendation. Do not assume a compound from the part number alone.

2. Match dimensions and OEM references exactly

For a replacement part, the OEM number and the size are the two most practical filters. Three published crankshaft listings show both:

Two further listings carry vehicle-specific references:

• Crankshaft rear seal, OEM 90311-40022, listed for Toyota.
• OEM 12279-D0100, listed for Nissan.

The listings give sizes as three numbers but do not state the units or which number is which. Confirm the units and the order of the figures before you check them against your shaft and housing drawings. The supplier also notes that product pictures may not match the exact part and are for reference only. Base your selection on the part number and measured dimensions, not the photo.

For an accurate quotation, the supplier asks buyers for the part number, machine model, quantity and size. For parts not shown in the catalog, the listings say OEM production is offered from a design drawing or a sample.

3. Define the operating conditions

A part that fits still has to survive the conditions it runs in. The supplier's listings describe these characteristics:

• The listing for 13042-16A06 says the part resists heat, oil, wear, fatigue, aging and friction, and stays stable in high-speed rotation.
• The listing for 90311-40022 describes the design as adaptable to machine vibration and spindle eccentricity, with a small axial dimension, and easy to disassemble and inspect.

These are qualitative descriptions. The approved listings give no numeric limits for temperature, pressure, shaft surface speed or eccentricity. If your application runs near any limit, such as hot engine zones, pressurized housings or high shaft speeds, send your actual values. Ask for the rated range of the proposed material and design in writing before you approve the order.

4. Check the listed commercial terms, then confirm them

The published listings state:

• Minimum order quantity: 100 pieces. The FAQ says small orders are accepted, but the unit price and freight cost will be higher than at MOQ.
• Samples: available.
• Packaging: standard box, neutral box or a box to the customer's requirements.
• Payment terms: L/C, D/A, D/P, PayPal, Western Union, T/T.
• Shipment: express, air or sea.

Quick selection checklist

1. Name the medium to be sealed and the contaminants to be kept out.
2. Give the OEM number, the vehicle or machine model, and the position.
3. Confirm the size, its units and the order of the dimensions against your drawing.
4. State temperature, pressure and shaft speed, and request a material recommendation from the available compounds.
5. Order a sample before buying in volume if the fit or the conditions are uncertain.
6. Confirm MOQ, packaging, price and lead time in writing.

When this guidance does not apply

The listings covered here are automotive parts, mainly for crankshafts. If your application needs documented numeric ratings, a specific certification or a compound proven for a particular chemical, the published listings are not enough. Ask for that documentation before you select a part. For unlisted parts, the route is OEM production from your drawing or sample, not a catalog match.