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.

  • MOQ: Flexible / Low MOQ Support
  • Lead Time: Prototype in 2-5 Days
  • Certifications: FDA, LFGB, ISO 9001, ROHS, REACH
  • Material: VMQ, FVMQ, LSR, HCR / HTV
  • Hardness: 30 to 80 Shore A (customizable)
  • Temperature: -60°C to 230°C (special grades to 300°C)
  • Custom Sizes: Per Your Drawing
  • Tooling: In-house mold design and machining
  • Samples: Free samples available

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

ImageProductTypeShort InfoAction
ISO 3601 Metric Silicone O-Rings 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 Custom Colors Silicone O-rings Color Silicone O-rings matched to your exact color sample or specification. View Details

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)
Adjustable Stud

Heavy Duty (ISO 6149-2)
Non-Adjustable Stud

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

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

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)

  • Note: If you came here looking for general O-ring sizes by inner diameter, please see our ISO 3601 Silicone O-Ring page instead.

Common Questions

Measure the fitting thread. ISO 6149 O-rings are matched to the thread size, not the groove size. If your fitting says M14 x 1.5, order the M14 size.

No. The inner diameter and cross section are different. A general ISO 3601 O-ring will not fit an ISO 6149 fitting correctly and may leak or get damaged.

Standard VMQ silicone is not recommended for petroleum-based hydraulic oil. FVMQ is better, but NBR or FKM is usually the best choice for oil. Tell us your fluid type and we will advise.

ISO 6149-2 is for non-adjustable stud ends (heavy duty). ISO 6149-3 is for adjustable stud ends (light duty). The O-ring size is the same for both. Only the fitting pressure rating changes.

Common sizes in VMQ are usually in stock. FVMQ and large quantities may need a short production run. Ask us and we will check.

Yes. We offer small sample packs. Contact us with your thread size and shipping address.