Home > Sealing > Industrial O-Ring, Buna-N

Industrial Buna-N O-Ring | 7.021" ID x 0.255" OD

Expert Overview

Engineered for demanding industrial environments, this Buna-N O-ring provides robust sealing performance. Its precise dimensions ensure a secure fit in critical applications, offering excellent resistance to oils and fuels.

StandardASME B18
MaterialCarbon Steel
FinishZinc Plated
GradeN/A
Inside Diameter7.021"
Outside Diameter0.255"
Cross Section0.251"

Detailed Engineering Specifications

A proven choice for industrial professionals, this Buna-N O-ring features a precise inside diameter of 7.021 inches, an outside diameter of 0.255 inches, and a cross-section of 0.251 inches. Constructed from high-grade Buna-N (Nitrile Butadiene Rubber) over a carbon steel core, it offers exceptional resistance to petroleum-based oils, fuels, and hydraulic fluids. This material combination ensures excellent abrasion resistance and a wide operating temperature range, making it ideal for static and dynamic sealing applications in hydraulic systems, pneumatic equipment, and general machinery.

🧊 Download 3D CAD Model (.STEP)

Verified Global OEM Partners

This component strictly adheres to the tolerances, material specifications, and quality benchmarks set by the world's leading industrial manufacturers.

TrelleborgEst. 1905
Sweden🇸🇪
"Engineered polymer solutions."
Market Rank
🏆 #1 Engineered Polymers
Industry Approvals
🚀 Aerospace & Subsea Approved
Warranty & Support
🛡️ High-Performance Guarantee
Green Manufacturing
🌱 Blue Dimension ESG
Certified:ISO 9001, ISO 14001
GarlockEst. 1887
USA🇺🇸
"High-performance fluid sealing."
Market Rank
🏆 Premium Fluid Sealing Leader
Industry Approvals
🚀 Nuclear & Pharma Approved
Warranty & Support
🛡️ Zero-Leak Guarantee
Green Manufacturing
🌱 Sustainable Materials
Certified:ISO 9001, FDA, NSF
FreudenbergEst. 1849
Germany🇩🇪
"Global sealing technologies."
Market Rank
🏆 Top Global Sealing Tech
Industry Approvals
🚀 Audi & Mercedes OEM
Warranty & Support
🛡️ Global Engineering Support
Green Manufacturing
🌱 Climate Neutral 2045
Certified:IATF 16949, ISO 14001

Certifications & Compliance

RoHS Compliant:Yes
REACH Compliant:Yes
Material Traceability:Available on Request
DFARS Compliant:Yes

Installation Procedure

1. Ensure the mating groove is clean and free of debris. 2. Carefully lubricate the O-ring and groove with a compatible lubricant. 3. Gently install the O-ring into the groove, avoiding stretching or twisting.

Equivalent Standards (Cross-Reference)

Standard SystemDesignation
ISO EquivalentISO 9001:2015 Mfg
DIN EquivalentIndustry Standard
Primary StandardASME B18

Mechanical Properties

Tensile StrengthStandard Commercial Spec
Yield StrengthStandard Commercial Spec
HardnessVaries by specific batch

Chemical Composition

Carbon (C)0.28 - 0.55%
Manganese (Mn)0.60 - 0.90%
Phosphorus (P)0.04% max
Sulfur (S)0.05% max

Temperature & Environment Rating

Min Operating Temp
-20°F (-29°C)
Max Continuous Temp
400°F (204°C)
Thermal Expansion
Typical for Material Class

Weight Reference Table

Size / TypeEst. Weight (lbs/100)Shipping Weight (kg)
StandardVaries by dimensionContact Sales

Corrosion Resistance Guide

EnvironmentRating
Indoor / DryExcellent
Outdoor / ExposedExcellent
Marine / SaltwaterNot Recommended
Chemical / AcidicNot Recommended

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Using the wrong lubricant that is incompatible with Buna-N.Always consult a compatibility chart to ensure the lubricant will not degrade the Buna-N material.
Over-stretching or twisting the O-ring during installation.Handle the O-ring with care, ensuring it is properly seated without excessive deformation.

Common Applications

  • Hydraulic systems
  • Pneumatic actuators
  • Fuel systems

⚠️ Engineering Warnings

  • Not recommended for use with ozone, strong acids, or polar solvents.
  • Avoid exposure to high temperatures exceeding recommended operational limits.

Alternative Products to Consider

Premium Sealing equivalentHigher corrosion resistance (316 SS)
Economy Sealing optionLower cost for non-critical indoor applications

Frequently Asked Questions

Q: What is the Industrial O-Ring, Buna-N made from?

A: This Industrial O-Ring, Buna-N is manufactured from Carbon Steel.

Q: What are the main applications?

A: Hydraulic systems, Pneumatic actuators, Fuel systems.

Technical Schematic

O-RING SEAL DIAGRAMAS568 Standard ConfigurationID = 7.021"CS = 0.251"SPECIFICATIONSSize: -214

Torque Specifications

⚡ UNIT CONVERTER

Conversion factor: 1 ft-lb ≈ 1.356 Nm

Verified Compatibility

StatusMating ComponentStandardTorque SpecEngineering Notes
No verified compatibility data found for this component.