Complete Size Database
Comprehensive AS568 aerospace standard database with all 200+ standard O-ring sizes, precise dimensional specifications, and tolerance data verified against AS568D current revision.
- ✓AS568-001 to AS568-475 complete range
- ✓Dimensional tolerances per AS568D standard
- ✓Cross-section range: 0.070" to 0.275"
Cross-Reference System
Accurate cross-reference data linking AS568 standard sizes to Parker 2-series, National Oil Seal, SKF, and other major manufacturer part numbers for seamless procurement and replacement.
- ✓Parker 2-series equivalents
- ✓National, SKF manufacturer codes
- ✓ISO 3601-1 metric equivalents
Groove Design Calculator
Professional groove design calculations for static and dynamic applications with recommended groove dimensions, surface finish requirements, and installation guidelines per AS568 standard.
- ✓Static sealing groove calculations
- ✓Dynamic application sizing
- ✓Surface finish specifications
AS568 Aerospace Standard Overview
The AS568 aerospace standard defines precision O-ring dimensional specifications used throughout aerospace, automotive, hydraulic, pneumatic, and industrial sealing applications. Originally developed for critical aerospace systems, AS568 has evolved to become the global industry standard for O-ring sizing, ensuring interchangeability and reliability across manufacturers and applications worldwide.
Current Revision AS568D
Latest Standard Specification
The AS568D revision provides the most current dimensional specifications, tolerance requirements, and material guidelines for O-ring sealing applications across all industries.
Complete Size Coverage
AS568-001 to AS568-475
Comprehensive coverage of all standard AS568 sizes from micro-miniature applications (0.029" ID) to large industrial sealing (18.890" ID) with five distinct cross-section series.
Precision Tolerances
±0.003" to ±0.024" Range
Tight dimensional tolerances ensure consistent sealing performance with inner diameter tolerances from ±0.005" to ±0.024" and cross-section tolerances from ±0.003" to ±0.005" depending on size.
AS568 Cross-Section Series Guide
AS568 standard organizes O-ring sizes into five distinct cross-section series, each optimized for specific application requirements and pressure ratings. Understanding cross-section selection is critical for achieving optimal sealing performance, proper compression ratios, and reliable service life in your application.
Micro Series (AS568-001 to 049)
Ultra-fine cross-section for precision instruments, electronics, medical devices, and miniature hydraulic systems. Ideal for space-constrained applications requiring reliable sealing.
Small Series (AS568-102 to 178)
Compact cross-section perfect for pneumatic systems, light hydraulics, and general-purpose sealing applications. Excellent balance of size and sealing capability.
Standard Series (AS568-201 to 284)
Most commonly used cross-section for hydraulic systems, automotive applications, and industrial machinery. The industry workhorse providing reliable sealing for standard pressure applications.
Medium Series (AS568-309 to 395)
Heavy-duty cross-section designed for high-pressure hydraulic systems, aerospace applications, and industrial equipment requiring enhanced sealing performance under demanding conditions.
Large Series (AS568-425 to 475)
Maximum cross-section for large bore sealing, industrial machinery, and applications requiring the highest sealing force and durability. Designed for the most demanding sealing challenges.
Most Popular AS568 Standard Sizes
These are the most frequently specified AS568 sizes across aerospace, automotive, hydraulic, and industrial applications. These popular sizes represent over 80% of all O-ring orders and are typically available for same-day shipping from most suppliers.
| AS568 Size | Inside Diameter | Outside Diameter | Cross Section | Parker Equivalent | Typical Applications |
|---|---|---|---|---|---|
| AS568-214 | 2.234" (56.74mm) | 2.512" (63.80mm) | 0.139" (3.53mm) | Parker 2-214 | Hydraulic cylinders, automotive systems |
| AS568-210 | 0.739" (18.77mm) | 1.017" (25.83mm) | 0.139" (3.53mm) | Parker 2-210 | Pneumatic applications, general sealing |
| AS568-220 | 1.239" (31.47mm) | 1.517" (38.53mm) | 0.139" (3.53mm) | Parker 2-220 | Industrial pumps, valve sealing |
| AS568-325 | 2.734" (69.44mm) | 3.154" (80.11mm) | 0.210" (5.33mm) | Parker 2-325 | Heavy-duty hydraulics, aerospace |
| AS568-110 | 0.362" (9.19mm) | 0.568" (14.43mm) | 0.103" (2.62mm) | Parker 2-110 | Small hydraulics, pneumatic fittings |
| AS568-112 | 0.487" (12.37mm) | 0.693" (17.60mm) | 0.103" (2.62mm) | Parker 2-112 | Automotive fuel systems, general use |
AS568 Technical Specifications & Tolerances
Precise dimensional specifications and tolerance requirements for AS568 standard O-rings. These specifications ensure interchangeability between manufacturers and reliable sealing performance across all applications. All dimensions follow AS568D current revision standards.
| Cross Section | Metric Equivalent | Size Range | ID Tolerance | CS Tolerance | Groove Width (Static) | Groove Depth |
|---|---|---|---|---|---|---|
| 0.070" | 1.78mm | AS568-001 to 049 | ±0.005" | ±0.003" | 0.105" | 0.053" |
| 0.103" | 2.62mm | AS568-102 to 178 | ±0.005" to ±0.007" | ±0.003" | 0.138" | 0.077" |
| 0.139" | 3.53mm | AS568-201 to 284 | ±0.007" to ±0.010" | ±0.004" | 0.174" | 0.103" |
| 0.210" | 5.33mm | AS568-309 to 395 | ±0.009" to ±0.015" | ±0.005" | 0.245" | 0.155" |
| 0.275" | 6.99mm | AS568-425 to 475 | ±0.012" to ±0.024" | ±0.005" | 0.310" | 0.200" |
Note: All specifications conform to AS568D standard. Groove dimensions shown are for static sealing applications. Dynamic sealing requires different groove specifications. Consult our engineering team for specific application requirements.
AS568 Material Selection Guide
All AS568 standard sizes are available in a comprehensive range of elastomer materials to meet diverse application requirements. Material selection is critical for achieving optimal sealing performance, chemical compatibility, temperature resistance, and service life in your specific application environment.
NBR (Nitrile Rubber)
Temperature Range: -40°F to +248°F (-40°C to +120°C)
Excellent oil and petroleum resistance make NBR the preferred choice for hydraulic systems, automotive applications, and general industrial sealing. Available in durometer ranges from 40-95 Shore A.
FKM (Viton) Fluorocarbon
Temperature Range: -4°F to +428°F (-20°C to +220°C)
Superior high-temperature and chemical resistance for demanding aerospace, automotive, and chemical processing applications. Excellent performance with aggressive chemicals and fuels.
EPDM Ethylene Propylene
Temperature Range: -67°F to +302°F (-55°C to +150°C)
Outstanding weather, ozone, and steam resistance make EPDM perfect for water systems, outdoor equipment, automotive brake systems, and HVAC applications.
Silicone (VMQ)
Temperature Range: -67°F to +482°F (-55°C to +250°C)
Exceptional temperature range and biocompatibility make silicone ideal for food processing, medical devices, pharmaceutical applications, and extreme temperature environments.
Why Engineers Trust AS568 Standard O-Rings
✓ Universal Interchangeability
AS568 standard ensures perfect interchangeability between manufacturers worldwide. Any AS568-214 from any certified supplier will have identical dimensions, enabling global sourcing flexibility and supply chain security.
✓ Precision Engineering
Tight dimensional tolerances and quality control standards ensure consistent sealing performance. ID tolerances as tight as ±0.005" and cross-section tolerances to ±0.003" guarantee reliable operation.
✓ Comprehensive Size Range
Complete coverage from micro-miniature (0.029" ID) to large industrial (18.890" ID) applications. Five cross-section series provide optimal solutions for every pressure and space requirement.
✓ Industry Proven Reliability
Decades of proven performance in aerospace, automotive, hydraulic, and industrial applications. Trusted by NASA, Boeing, General Motors, and thousands of engineering teams worldwide.
Find Your AS568 Standard O-Ring Solution
Access our complete AS568 database with over 200 standard sizes, precise dimensional data, cross-reference information, and material specifications. Trusted by engineers worldwide for critical sealing applications.
200+ AS568 sizes • Precision tolerances • Multiple materials • Same-day availability • Technical support