Material specification page for metric o-rings (iso 3601) in Silicone (VMQ). Covers the grade designation (vinyl-methyl silicone, typically 70 Shore A), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to ISO 3601-1 (fluid power — O-rings, inside diameters and cross-sections).
Why Choose Silicone (VMQ) for Metric O-Rings (ISO 3601)
Used for wide temperature range and food/medical contact, in static seals only. For metric o-rings (iso 3601), this matters when inert and physiologically neutral; low tear and abrasion strength is the primary requirement.
Mechanical & Physical Properties
| Grade designation | vinyl-methyl silicone, typically 70 Shore A |
|---|---|
| Magnetic response | Non-magnetic |
| Service temperature | approx. -60 °C to +200 °C |
| Corrosion characteristic | Inert and physiologically neutral; low tear and abrasion strength |
Corrosion Behavior in Service
Carbon and alloy steel metric o-rings (iso 3601) require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Comparable Grades
For metric o-rings (iso 3601), consider NBR or FKM wherever the seal is dynamic — silicone has low tear and abrasion strength and is a static-seal material. Elastomer selection is decided by the medium, the temperature range and whether the seal is static or dynamic — not by strength.
Sizes of Metric O-Rings (ISO 3601) Available in Silicone (VMQ)
| Cross-section (mm) | Typical inside-diameter range (mm) | Common compounds | Notes |
|---|---|---|---|
| 1.0 | 1.0 – 20 | NBR, FKM, EPDM, silicone | miniature and pneumatic |
| 1.5 | 2.0 – 40 | NBR, FKM, EPDM, silicone | small pneumatic and instrument |
| 1.78 | 1.78 – 50 | NBR, FKM, EPDM | nearest metric equivalent to the 1/16 in section |
| 2.0 | 3.0 – 100 | NBR, FKM, EPDM, silicone | general hydraulic and pneumatic |
| 2.5 | 5.0 – 150 | NBR, FKM, EPDM | general hydraulic |
| 3.0 | 6.0 – 200 | NBR, FKM, EPDM | general hydraulic |
| 3.5 | 10 – 250 | NBR, FKM | hydraulic |
| 4.0 | 12 – 300 | NBR, FKM | hydraulic and larger flanges |
| 5.0 | 20 – 400 | NBR, FKM | large flanges and covers |
| 5.33 | 20 – 400 | NBR, FKM | nearest metric equivalent to the 3/16 in section |
| 6.0 | 25 – 500 | NBR, FKM | large covers and housings |
Dimensions are independent of the material: every size above is available in Silicone (VMQ).
Custom manufacturing · Made to drawing
Need this seal in a grade that is not listed?
Silicone is one of the grades the catalog describes. Inside diameter, cross-section and compound are the three that matter, and the compound is chosen against the fluid and the temperature rather than the dimensions.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
