ISO 6149 Metric Silicone O-Rings
Manufacturer & Custom Solutions
ISO 6149 Metric Silicone O-Rings
ZSR Silicone makes silicone O-rings that match ISO 6149 metric hydraulic fittings. No guessing. Pick by your thread size (M8 to M60) and we send the right seal. VMQ and FVMQ grades in stock. Custom orders welcome.
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-Rings Options
Every Silicone Grade, One Perfect Seal
Every O-ring starts with the right compound. Platinum-cured and peroxide-cured systems are available for all grades — we recommend platinum cure for food and medical contact.
| Grade | Hardness (Shore A) | Temperature | Compliance | Best For |
|---|---|---|---|---|
| Industrial VMQ | 30 – 80 | -60°C to +230°C | RoHS / REACH | General industrial sealing |
| FDA Food Grade | 30 – 70 | -60°C to +230°C | FDA 21 CFR 177.2600 | Food & beverage equipment |
| Medical Grade (Platinum) | 10 – 70 | -60°C to +230°C | USP Class VI | Medical devices & laboratory |
| High Temperature | 40 – 80 | up to +300°C | RoHS | Ovens, lighting, engine bays |
| Fluorosilicone (FVMQ) | 40 – 80 | -60°C to +200°C | RoHS | Fuel, oil & solvent exposure |
| LSR (Liquid Silicone) | 10 – 80 | -60°C to +230°C | FDA / medical grades | High-volume precision parts |
| Transparent / Clear | 30 – 70 | -60°C to +200°C | FDA options | Visual inspection points |
From 0.5 mm ID to Oversized Joint Rings
Size, cross-section and tolerance are fully custom. Send a drawing, a standard size number (e.g., AS568-214), or a physical sample — we handle the rest.
| Item | Range / Options |
|---|---|
| Size Range | ID 0.5 – 500 mm+; molded or vulcanized-joint for oversized IDs |
| Cross-Section | 0.5 – 10 mm; round (standard), square-cut, custom profile |
| Size Standards | AS568 · JIS B2401 · BS 1806 · DIN 3771 · ISO 3601 · ISO 6149 · AN6227 / AN6230 (see standards table below) |
| Tolerance | ISO 3302-1 class per size & process; ±0.05 mm on small molded rings |
| Custom Geometry | Non-standard ID / cross-section from your drawing or sample |
| Surface | Standard finish / PTFE-coated for low friction |
Any Color Your Brand or Assembly Needs
We color-match silicone compounds to Pantone or RAL references, including translucent and transparent grades for visual inspection points.
Your Brand, Built Into the Part
Branding, part numbers and batch traceability — molded in, engraved or printed, without compromising the seal.
Molded, Spliced or Coated — One Factory
Molding, splicing and finishing under one roof — we match the process to your volume, size and tolerance target.
| Process | How It Works | Best For |
|---|---|---|
| Compression Molding | Pre-formed silicone pressed and cured in a heated mold | Medium volumes, large cross-sections |
| LSR Injection Molding | Liquid silicone injected into closed molds | High volumes, tight tolerances |
| Vulcanized Joint (Spliced) | Extruded cord cut to length and vulcanized into a ring | Oversized IDs, low volumes, fast tooling |
| PTFE Coating | Low-friction coating applied to finished rings | Dynamic sealing, easy installation |
| Rapid Prototyping | Prototype tooling before production mold | Fit & function validation |
Related Silicone O-ring
| Image | Product | Type | Short Info | Action |
|---|---|---|---|---|
| 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 |
| JIS B2401 Silicone O-Ring | Standard & Size | Japanese industrial standard O-rings commonly used in Asian-manufactured machinery and automotive equipment. | View Details |
| 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 |
| 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 |
| 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 |
| 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 |
 | VMQ Silicone O-Rings | Materials | Heat and cold-resistant silicone O-rings for food, medical, automotive, and industrial applications. | 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 |
| Fiberglass Reinforced Silicone O-rings | Materials | High-strength silicone O-rings reinforced with fiberglass fabric. Withstands extreme heat and pressure. | 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 |
| Custom Colors Silicone O-rings | Color | Silicone O-rings matched to your exact color sample or specification. | View Details |
What Is an ISO 6149 O-Ring?
ISO 6149 is not an O-ring size standard. It is a hydraulic fitting standard. It tells you the shape of the port and the thread on a metric hydraulic connector. The O-ring is just the soft seal that sits on the male fitting to stop leaks.
That means you do not buy this O-ring by its inner diameter. You buy it by the thread size of your fitting. If your fitting says M14 x 1.5, you need the matching O-ring made for M14 x 1.5.
Quick check: If you are looking at a table of inner diameters and cross sections, that is ISO 3601 (general O-rings). If you have a metric hydraulic fitting and need the seal that goes with it, you are in the right place. That is ISO 6149.
How the Seal Works
The male half of the fitting carries the O-ring. The female port has a machined angle (chamfer). When you tighten the fitting, the O-ring squeezes against the chamfer to make the seal. The metal threads do not seal; they only hold the parts together.
ISO 6149 vs ISO 3601: Do Not Mix Them Up
Option / Standard | ISO 3601 O-Ring | ISO 6149 O-Ring |
|---|---|---|
What it is | General O-ring size standard | Hydraulic fitting standard with matching seal |
How you pick it | By inner diameter and cross section | By the thread size of your fitting |
Number of sizes | Hundreds (Class A and B) | 13 standard sizes only |
Typical use | Static and dynamic seals anywhere | Metric hydraulic ports and stud ends only |
Standard reference | ISO 3601-1 | ISO 3601-5 (via ISO 6149-2 / 6149-3) |
ISO 6149 Silicone O-Ring Size Chart
Below is the full list of 13 standard sizes. Each row shows the thread size, the matching O-ring dimensions, and common names used in the market.
Table 1: O-Ring Dimensions by Thread Size
Thread Size | O-Ring Name | Cross Section (mm) | Inside Diameter (mm) | Cross Section (inch) | Inside Diameter (inch) |
|---|---|---|---|---|---|
M8 x 1 | M8 ISO-Ring | 1.60 | 6.10 | 0.063 | 0.240 |
M10 x 1 | M10 ISO-Ring | 1.60 | 8.10 | 0.063 | 0.319 |
M12 x 1.5 | M12 ISO-Ring | 2.20 | 9.30 | 0.087 | 0.366 |
M14 x 1.5 | M14 ISO-Ring | 2.20 | 11.30 | 0.087 | 0.445 |
M16 x 1.5 | M16 ISO-Ring | 2.20 | 13.30 | 0.087 | 0.524 |
M18 x 1.5 | M18 ISO-Ring | 2.20 | 15.30 | 0.087 | 0.602 |
M20 x 1.5 | M20 ISO-Ring | 2.20 | 17.30 | 0.087 | 0.681 |
M22 x 1.5 | M22 ISO-Ring | 2.20 | 19.30 | 0.087 | 0.760 |
M27 x 2 | M27 ISO-Ring | 2.90 | 23.60 | 0.114 | 0.929 |
M33 x 2 | M33 ISO-Ring | 2.90 | 29.60 | 0.114 | 1.165 |
M42 x 2 | M42 ISO-Ring | 2.90 | 38.60 | 0.114 | 1.520 |
M48 x 2 | M48 ISO-Ring | 2.90 | 44.60 | 0.114 | 1.756 |
M60 x 2 | M60 ISO-Ring | 2.90 | 56.60 | 0.114 | 2.228 |
* M20 x 1.5 is mainly used for cartridge valve plugs (see ISO 7789). All dimensions follow ISO 3601-5 as referenced by ISO 6149-2 and ISO 6149-3.
Table 2: Pressure Ratings by Thread Size
ISO 6149 fittings come in light duty and heavy duty. The safe working pressure depends on the fitting type, not just the O-ring.
Thread Size | Light Duty (ISO 6149-3) | Heavy Duty (ISO 6149-2) |
|---|---|---|
M8 x 1 | 31.5 MPa (315 bar) | 40 MPa (400 bar) |
M10 x 1 | 31.5 MPa (315 bar) | 40 MPa (400 bar) |
M12 x 1.5 | 31.5 MPa (315 bar) | 40 MPa (400 bar) |
M14 x 1.5 | 31.5 MPa (315 bar) | 40 MPa (400 bar) |
M16 x 1.5 | 25 MPa (250 bar) | 31.5 MPa (315 bar) |
M18 x 1.5 | 25 MPa (250 bar) | 31.5 MPa (315 bar) |
M22 x 1.5 | 25 MPa (250 bar) | 31.5 MPa (315 bar) |
M27 x 2 | 16 MPa (160 bar) | 20 MPa (200 bar) |
M33 x 2 | 16 MPa (160 bar) | 20 MPa (200 bar) |
M42 x 2 | 16 MPa (160 bar) | 20 MPa (200 bar) |
M48 x 2 | 16 MPa (160 bar) | 20 MPa (200 bar) |
M60 x 2 | 10 MPa (100 bar) | 16 MPa (160 bar) |
* Pressures are guide values from ISO 6149-2 and ISO 6149-3. Always confirm with your fitting supplier for your exact application.
Table 3: Common Industry Part Numbers (Cross Reference)
If you have a Parker, Global O-Ring, or other supplier part number, use this table to find the matching ZSR Silicone size.
Thread Size | ZSR Size Code | Parker Ref. | Global O-Ring Ref. |
|---|---|---|---|
M8 x 1 | ISO-M8 | 0024-0063 | 1.60X006.1 |
M10 x 1 | ISO-M10 | 0031-9063 | 1.60X008.1 |
M12 x 1.5 | ISO-M12 | 0036-6087 | 2.20X009.3 |
M14 x 1.5 | ISO-M14 | 0044-5087 | 2.20X011.3 |
M16 x 1.5 | ISO-M16 | 0052-4087 | 2.20X013.3 |
M18 x 1.5 | ISO-M18 | 0060-2087 | 2.20X015.3 |
M20 x 1.5 | ISO-M20 | 0068-1087 | 2.20X017.3 |
M22 x 1.5 | ISO-M22 | 0076-0087 | 2.20X019.3 |
M27 x 2 | ISO-M27 | 0092-9114 | 2.90X023.6 |
M33 x 2 | ISO-M33 | 0116-5114 | 2.90X029.6 |
M42 x 2 | ISO-M42 | 0152-0114 | 2.90X038.6 |
M48 x 2 | ISO-M48 | 0175-6114 | 2.90X044.6 |
M60 x 2 | ISO-M60 | 0222-8114 | 2.90X056.6 |