Standard Packaging

Each batch of NBR O-rings is first packed in sealed PE bags to prevent moisture, dust and contamination. Small-size rings (cross-section below 3mm) are packed at 5,000 pcs per bag; large-size rings (cross-section above 4mm) at 2,000 pcs per bag. Bags are then placed into export cartons at 15–30 kg per carton, with standard carton dimensions of 50×35×32 cm. Cartons are secured with packing straps, stacked on fumigated wooden pallets (treated in accordance with GB/T 28060 and marked with IPPC certification) and wrapped with stretch film for moisture protection and load stability during container stuffing. Pallet dimensions and per-pallet carton quantities are determined by the total order volume. All packaging complies with GB/T 5721-1993 for rubber sealing products and GB/T 19142 for export shipments.

Shipping

We support FCL and LCL sea freight, air freight, and express delivery depending on order quantity and destination. Available trade terms include EXW, FOB, and CIF. Other terms may be available upon request. Shipping costs are calculated based on cargo volume, gross weight, destination, and selected transportation method.

Shipping documents provided with each shipment include: commercial invoice, packing list, bill of lading (or air waybill), certificate of origin, inspection certificate, and material compliance certificates as applicable.

Lead Time

Samples: 7 working days

Standard orders: 15–25 working days

Customized orders (non-standard sizes/materials): 25–40 working days

Q1: Do you provide samples? Are they free?

Yes. Standard sizes are free; you pay shipping only. Custom samples are charged case by case.

Q2: What information do you need for a custom order?

Provide: inner/outer diameter, cross-section (wire diameter), material (NBR/EPDM/FKM), hardness (Shore A 30–90), working temperature, and contact media (oil/water/chemicals). Drawings or physical samples are helpful.

Q3: What is the MOQ and lead time?

MOQ: 50–100 pieces for standard sizes; non-standard negotiable. Lead time: 5–10 days for in-stock items; 15–20 days for custom production, depending on quantity.

Q4: What quality standards and certifications do you meet?

Comply with AS568, DIN 3771, JIS B 2401. FDA-compliant NBR available. Every batch is tested for hardness, tensile strength, compression set, and oil resistance.

Q5: What factors should I consider when choosing an NBR ring?

Four key factors: working temperature (NBR works -30°C to 100°C; above that accelerates aging), media type (good for petroleum oils/fuels/hydraulic fluids, but not for ozone, polar solvents, or outdoor use), movement type (static or dynamic), and hardness (typically 70 Shore A, adjust for pressure).

Q6: How does NBR compare to FKM and EPDM?

NBR: -30~100°C, good oil resistance, low cost, but poor ozone/outdoor/polar solvent resistance.

FKM: -20~200°C, high temperature and chemical resistance, but higher cost.

EPDM: -40~130°C, excellent weather/ozone/steam resistance, but not resistant to mineral oils or fuels.

Choose NBR for oils, FKM for high heat/aggressive chemicals, EPDM for outdoor or water/steam systems.

Q7: What quality tests are performed on NBR rings?

Tensile strength and elongation per ASTM D412/ISO 37 – minimum 10 MPa and 200%. Hardness per ASTM D2240 – 70±5 Shore A. Compression set per ASTM D395/ISO 815 – less than 25% after 70 hours at 100°C. Oil resistance per ASTM D471 – volume change between -5% and +10% in ASTM #3 oil.