Side-by-Side Comparison
O-Rings & Rotary Seals
Metric O-Rings vs. Rotary Shaft Oil Seals
Comparing 2 standards across 14 specifications. 14 key differences identified.
Comparing:
Metric O-Rings
Rotary Shaft Oil Seals
Metric O-rings under ISO 3601-1 and DIN 3771 are designated directly by inside diameter (d_1) and cross-section cord diameter (d_2) in millimeters (e.g. 15.0 × 2.5 mm), matching standard metric groove depths and dynamic cylinder bores.
Radial rotary shaft oil seals retain lubricating grease/oil and exclude contaminants along rotating shafts, standardized under DIN 3760 / ISO 6194 by three boundary dimensions: Shaft Diameter (d_1), Housing Bore Diameter (d_2), and Seal Width (b).
Specification Comparison Table
14 Parameters| Parameter / Spec | ||
|---|---|---|
|
Governing Standards
|
ISO 3601-1 (Class A & B tolerances) / DIN 3771-1 | DIN 3760 / ISO 6194-1 / RMA OS-1 |
|
Callout Designation
|
[Inside Diameter d₁ in mm] × [Cross-Section d₂ in mm] (e.g. 20.0 × 3.0) | — |
|
Standard Metric Cord Sizes (d₂)
|
1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 5.7, 6.0, 7.0, 8.0 mm | — |
|
Micro / Miniature Metric Series
|
0.5 mm to 1.2 mm cross-section for watch crowns and precision instruments | — |
|
Static Gland Compression Ratio
|
18% to 28% of cord diameter d₂ | — |
|
Dynamic Gland Compression Ratio
|
10% to 18% of cord diameter d₂ | — |
|
Hardness Benchmark
|
70 Shore A (General pneumatic/hydraulic) vs 90 Shore A (High pressure > 100 bar) | — |
|
Dimension Format
|
— | [Shaft Diameter d₁] × [Bore Diameter d₂] × [Width b] in mm (e.g. 25 × 40 × 7) |
|
DIN 3760 Type A (ISO Form SC)
|
— | Elastomer-encased outer metal case, single sealing lip with garter spring |
|
DIN 3760 Type AS (ISO Form TC)
|
— | Elastomer-encased outer metal case, primary sprung lip + auxiliary dust wiper lip |
|
DIN 3760 Type B (ISO Form SB)
|
— | Exposed precision-ground metal outer diameter, pressed into cast iron housings |
|
Garter Spring Material
|
— | Carbon spring steel (Standard) or AISI 302/316 Stainless Steel (Corrosion/Marine) |
|
Shaft Surface Finish Requirement
|
— | Ra 0.2 to 0.8 µm (Rz 1.0 to 4.0 µm) plunge-ground without spiral machining lead |
|
Shaft Hardness at Seal Track
|
— | 45 to 60 HRC minimum (prevents grooving under seal lip) |