Cord rings / Cord stock
Highest quality cord rings / cord stock
Use and properties of cord rings
Cord rings are used in particular when suitable O-ring shapes are not available and the small quantity does not economically justify the production of a tool.
In contrast to compression-molded O-rings, cord rings are made from extruded cord and joined to any inside diameter by butt vulcanization – or, less frequently, by gluing. The butt-vulcanized version has become established because it offers physically better properties.
Nevertheless, the vulcanization point remains less mechanically resilient than with endlessly manufactured O-rings. Therefore, cord rings are not suitable for dynamic seals or for use in vacuum or gaseous media.
The result: economical sealing solutions for static applications – with individually manufactured diameters and controlled dimensional tolerance.
- Manufactured according to DIN ISO 3302-1, E2 (cord diameter) and L2 (extended length)
- Not suitable for dynamic seals or vacuum applications
- Alternative to O-rings for small quantities and special dimensions
- Stock items in NBR 70 black and FKM 75 black – E1 tolerance on request
- Tighter tolerances can be achieved on request
Tolerances with Cross-Section
| TOLERANZEN FÜR QUERSCHNITTSMASSE (SCHNURDURCHMESSER D2) | DIN 7715 TEIL 3 E2 TOLERANZ ± |
|---|---|
| bis 2.50 mm | ± 0.35 mm |
| 2.50- 4.00 mm | ± 0.40 mm |
| 4.00- 6.30 mm | ± 0.50 mm |
| 6.30-10.00 mm | ± 0.70 mm |
| 10.00-16.00 mm | ± 0.80 mm |
| 16.00-25.00 mm | ± 1.00 mm |
Comparison Table
| Rund-Schnur-Durchm. | Standard Toleranz (DIN 7715 E2) | Premium Toleranz | Engere Toleranz um ca. |
|---|---|---|---|
| 1.78 mm | ±0.35 mm | ±0.10 mm | 29% |
| 2.00 mm | ±0.35 mm | ±0.10 mm | 29% |
| 2.40 mm | ±0.35 mm | ±0.12 mm | 34% |
| 2.62 mm | ±0.40 mm | ±0.12 mm | 30% |
| 3.00 mm | ±0.40 mm | ±0.12 mm | 30% |
| 3.18 mm | ±0.40 mm | ±0.15 mm | 38% |
| 3.53 mm | ±0.40 mm | ±0.15 mm | 38% |
| 4.00 mm | ±0.40 mm | ±0.15 mm | 38% |
| 4.50 mm | ±0.50 mm | ±0.20 mm | 40% |
| 4.80 mm | ±0.50 mm | ±0.20 mm | 40% |
| 5.00 mm | ±0.50 mm | ±0.20 mm | 40% |
| 5.34 mm | ±0.50 mm | ±0.20 mm | 40% |
| 5.50 mm | ±0.50 mm | ±0.25 mm | 50% |
| 5.70 mm | ±0.50 mm | ±0.25 mm | 50% |
| 6.00 mm | ±0.50 mm | ±0.25 mm | 50% |
| 6.35 mm | ±0.70 mm | ±0.25 mm | 36% |
| 6.50 mm | ±0.70 mm | ±0.25 mm | 36% |
| 6.99 mm | ±0.70 mm | ±0.25 mm | 36% |
| 7.50 mm | ±0.70 mm | ±0.25 mm | 36% |
| 8.00 mm | ±0.70 mm | ±0.25 mm | 36% |
| 8.40 mm | ±0.70 mm | ±0.25 mm | 36% |
| 9.00 mm | ±0.70 mm | ±0.25 mm | 36% |
| 9.52 mm | ±0.70 mm | ±0.25 mm | 36% |
| 10.00 mm | ±0.70 mm | ±0.33 mm | 47% |
| 11.10 mm | ±0.80 mm | ±0.38 mm | 48% |
| 12.00 mm | ±0.80 mm | ±0.45 mm | 56% |
| 12.70 mm | ±0.80 mm | ±0.45 mm | 56% |
| 13.00 mm | ±0.80 mm | ±0.45 mm | 56% |
| 14.00 mm | ±0.80 mm | ±0.50 mm | 63% |
| 14.30 mm | ±0.80 mm | ±0.50 mm | 63% |
| 15.00 mm | ±0.80 mm | ±0.50 mm | 63% |
| 15.90 mm | ±0.80 mm | ±0.50 mm | 63% |