ISO 3601 Metric Silicone O-Rings
Manufacturer & Custom Solutions
ISO 3601 Metric Silicone O-Rings
ZSR Silicone manufactures ISO 3601-1 compliant silicone O-rings in Class A, Class B, and custom sizes. From food-grade VMQ to high-performance FVMQ. Fast quotes. Small batch to bulk order.
FDA 21 CFR 177.2600
Rubber Articles Intended for Repeated Use
LFGB 30&31
EU Food Contact Materials
USP Class VI / ISO 10993
Biocompatibility of Medical Devices
RoHS / REACH
Environmental Compliance
UL 94
Flammability of Plastic Materials
Built to Your Exact Spec
Custom Silicone O-ring Options
| Image | Product | Type | Short Info | Action |
|---|---|---|---|---|
 | ISO 3601 Metric Silicone O-Rings | Standard & Size | Metric silicone O-rings manufactured to ISO 3601 dimensions. Fits international equipment groove standards. | View Details |
 | ISO 6149 Metric Silicone O-Rings | Standard & Size | Metric O-rings designed for hydraulic and pneumatic fluid power sealing applications under ISO 6149 standards. | View Details |
 | BS 1806 Silicone O-rings | Standard & Size | British Standard inch-size silicone O-rings. Common in UK and Commonwealth industrial equipment. | View Details |
 | DIN 3771 Silicone O-rings | Standard & Size | German metric standard O-rings for hydraulic and pneumatic sealing in European machinery. | View Details |
 | Custom Molded Silicone O-rings | Standard & Size | Custom-shaped silicone O-rings molded to your exact drawing or sample. No standard size limitations. | View Details |
 | AS568 Silicone O-rings | Standard & Size | Inch-size silicone O-rings that follow the AS568 standard. Widely used in North American machinery and hydraulic systems. | View Details |
 | AN6227 Silicone O-rings | Standard & Size | Aerospace-standard O-rings with small cross-section. Used in aviation and military-grade sealing. | View Details |
 | AN6230 Silicone O-rings | Standard & Size | Aerospace-standard O-rings specified under AN6230 for aviation and military-grade sealing. | View Details |
 | JIS B2401 Silicone O-Ring | Standard & Size | Japanese industrial standard O-rings commonly used in Asian-manufactured machinery and automotive equipment. | View Details |
 | FDA Food Grade Silicone O-Rings | Grade | Food-safe silicone O-rings compliant with FDA regulations. Safe for repeated food contact. | View Details |
 | Industrial Grade Silicone O-ring | Grade | General-purpose silicone O-rings for industrial sealing. Cost-effective with reliable performance. | View Details |
 | Medical Grade Silicone O-ring | Grade | Biocompatible silicone O-rings for medical devices. Passes USP Class VI and supports sterilization. | View Details |
 | Oil-Resistant / Fuel-Resistant Silicone O-Rings | Special Function | Modified silicone O-rings that resist swelling in oils, fuels and petroleum-based fluids. | View Details |
 | Metal Detectable Silicone O-Rings | Special Function | Food-safe silicone O-rings with metal-detectable additives. Protects production lines from contamination. | View Details |
 | High Temperature / Heat Resistant Silicone O-Rings | Special Function | Silicone O-rings that stay flexible at temperatures above 200°C. For ovens, engines and furnaces. | View Details |
 | VMQ Silicone O-Rings | Materials | Heat and cold-resistant silicone O-rings for food, medical, automotive, and industrial applications. | View Details |
 | Fiberglass Reinforced Silicone O-rings | Materials | High-strength silicone O-rings reinforced with fiberglass fabric. Withstands extreme heat and pressure. | View Details |
 | HCR / HTV / Solid Silicone Rubber O-rings | Materials | Durable solid silicone rubber O-rings made by compression molding. The standard choice for general sealing. | View Details |
 | Liquid Silicone Rubber (LSR) O-rings | Materials | Injection-molded liquid silicone rubber O-rings with tight tolerances and clean surfaces. Ideal for high-volume production. | View Details |
 | Platinum Cured Silicone O-rings | Materials | Ultra-clean silicone O-rings cured with platinum catalyst. Lower extractables for food and medical use. | View Details |
 | Fluorosilicone (FVMQ) O-rings | Materials | Fuel and oil-resistant silicone O-rings for aerospace, automotive and chemical applications. | View Details |
 | Transparent / Clear Silicone O-rings | Color | See-through silicone O-rings for visual inspection and clean-looking medical or food equipment. | View Details |
 | Black / White Silicone O-Rings | Color | Standard black and white silicone O-rings. The most common colors for industrial and food-grade applications. | View Details |
 | Pantone Colors Silicone O-rings | Color | Silicone O-rings in any Pantone color for branding, color-coding or aesthetic requirements. | View Details |
 | Custom Colors Silicone O-rings | Color | Silicone O-rings matched to your exact color sample or specification. | View Details |
ISO 3601 Size System (Metric)
ISO 3601 gives two groups of sizes. Class A uses inch-based sizes turned into millimeters. Class B uses true metric sizes. The size code tells you the cross section and the inner diameter.
How to Read the Size Code
Cross Section Groups
Group | Cross Section (mm) | Typical Use |
|---|---|---|
A | 1.80 mm | Small precision parts, medical devices |
B | 2.65 mm | General fluid sealing, appliances |
C | 3.55 mm | Hydraulic and pneumatic systems |
D | 5.30 mm | Heavy-duty static seals |
E | 6.99 mm | Large groove, low compression designs |
Quality Levels: Grade N, S, and CS
We follow ISO 3601-3 to check surface quality. Not every job needs the same level. We offer three grades so you do not pay for more than you need.
Grade N
Normal grade. Good for general-purpose seals, household goods, and standard machines. Checks for flash, bubbles, and cuts.
Grade S
Strict grade. Better surface finish. For industrial and aerospace parts where leaks are costly.
Grade CS
Critical grade. The highest level. For aerospace, oxygen service, and life-support systems where zero defects matter.
What we check: flash, offset, parting-line, back-rind, flow marks, non-fills, and indentations. Stricter checks are available on request.
Silicone Material Options
We do not sell "one type of silicone." We match the rubber to your job. Pick from VMQ for general use or FVMQ when you need fuel and oil resistance too.
Property | VMQ (Standard Silicone) | FVMQ (Fluorosilicone) |
|---|---|---|
Temp Range | -60°C to +200°C | -60°C to +175°C |
Hardness | 50 to 80 Shore A | 50 to 80 Shore A |
Color | Red, white, translucent, blue, black | Blue, black |
Fuel / Oil | Not recommended | Good resistance |
Common Grades | FDA, Medical, General | Industrial, Aerospace |
Certifications Available
What Is an ISO 3601 Metric Silicone O-Ring?
An ISO 3601 O-ring is the world's most common standard for O-ring size and tolerance. The standard is split into parts. ISO 3601-1 controls the size and tolerance. ISO 3601-3 controls the surface quality.
At ZSR Silicone, we make these O-rings from silicone rubber (VMQ or FVMQ). Silicone works in extreme heat and cold, does not smell, and meets food and medical rules. That is why engineers pick silicone for food machines, medical devices, and outdoor sealing.
Class A
Tight tolerance. Same sizes as AS568 dash numbers. Best for aerospace, precision hydraulics, and critical sealing.
Class B
Wider tolerance. True metric sizes made for metric grooves. Best for general industrial and consumer goods.
Custom
Need a size not in the book? We cut molds or machine-produce special inner diameters and cross sections.
