.275" Square Nitrile Buna-N 70 O-Ring Cord Stock Black (.266"/6.73mm CS)

The SN70.275 Square Buna-N (Nitrile) O-Ring cord stock provides a durable, oil-resistant sealing solution with a true 70 Shore A durometer hardness. Precision-made in a black nitrile compound, this square cord stock delivers reliable sealing performance, reduced downtime, and excellent versatility for fabricating custom O-Rings. Its square profile increases sealing surface area, ensuring better compression and leak prevention compared to standard round cord stock.

Operating temperature: -40° to +225°F (–40° to +107°C)

Material & Performance Details

• Compound: Buna-N (Nitrile)
• Durometer: 70 Shore A
• Color: Black

Performance strengths:

• Excellent resistance to oils and fuels
• Strong abrasion and wear resistance
• Reliable sealing under static compression

Chemical compatibility:

• Excellent resistance to: petroleum oils, diesel fuel, mineral oils, hydraulic oils (petroleum base)
• Limited capability with: dilute acids, water, alcohols
• Not compatible with: brake fluids (glycol-based), strong oxidizers, ketones, phosphate esters

Sizes & Measurements

• Cross Section (CS): 6.73 mm | 0.266"
• Nominal Size: .275" square
• Inside Diameter (ID): Cut-to-length per requirement
• Outside Diameter (OD): Varies with cut ID + CS
• Part Number: SN70.275
• AS568 Dash Number: Not applicable (cord stock, cut-to-fit)

Applications & Use Cases

SN70.275 Square Buna-N cord stock is used to fabricate custom O-Rings and seals in:

• Hydraulic cylinders and pumps
• Pneumatic sealing systems
• Automotive engines and fuel systems
• Agricultural and heavy equipment
• Oil and gas machinery
• General industrial maintenance

Its square cross-section provides greater sealing contact than round cord, making it ideal for static sealing in higher-pressure applications.

Key Specifications

• Material: Buna-N (Nitrile)
• Durometer: 70 Shore A
• Color: Black
• Certifications: COTS CofC
• Temperature range: -40° to +225°F (–40° to +107°C)
• Pressure ratings: Application dependent; optimized for static sealing

Why Buy from The O-Ring Store LLC

• ISO9001:2015 certified quality processes
• USA stock for fast delivery
• Same-day shipping on in-stock items
• Custom lengths and vulcanized O-Rings available
• Full lot traceability & documentation on request
• Expert technical support from experienced staff
• Competitive pricing with uncompromised quality

FAQs

Q1: Can I order this cord stock cut to specific lengths?
Yes. We provide bulk lengths or custom-cut lengths to fit your exact sealing needs.

Q2: How is square cord stock different from round cord stock?
Square cord provides a larger sealing contact surface, improving sealing reliability in static applications.

Q3: Can I make my own O-Rings from this cord stock?
Yes. Pair with an O-Ring splice kit and adhesive for quick, custom O-Ring fabrication on site.