Our ProductsCord rings

Round cord rings are often used in cases where no suitable O-ring forms are available and the small number of pieces means that tool manufacture is not cost-effective.

 

In contrast to moulded vulcanised O-rings, round cord rings made of extruded cord are assembled to any inner diameter by gluing or impact vulcanisation. In recent years, however, gluing has largely been discontinued, as the round cord, butt-jointed DIN 7715, has become more and more accepted due to better physical values, among other things. However, the vulcanization site has lower mechanical properties than the extruded cord. Round cord rings should therefore not be used for dynamic seals, vacuum and gaseous media. For the cord diameter the dimensional deviation according to Din 7715 Part 3, Class E2 applies, or for the circumferences ± 0.8 percent. The O-ring tolerances are not applicable.

Tolerances for cross-section dimensions (cord diameter D2) DIN 7715 Part 3 E2 Tolerance ±
up to 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