O-Ring 7x1.8 VMQ 70 ShA Silicone

O-Ring 7x1.8 VMQ 70 ShA Silicone - 100 pcs

O-Ring 7x1.8 VMQ 70 ShA is a silicone sealing ring with an inside diameter of 7 mm and a cross-section of 1.8 mm, manufactured from VMQ silicone rubber with a nominal hardness of 70 Shore A. The calculated outside diameter is 10.6 mm. The O-ring has a round cross-section and is intended for installation in a correctly designed sealing groove. The package contains 100 pcs.

Technical data

An unverified operating temperature range, resistance to specific fluids or regulatory approvals are not assigned to this SKU because these properties depend on the exact VMQ compound formulation.

O-Ring 7x1.8 mm dimensions

The designation 7x1.8 mm defines the two fundamental dimensions of the O-ring:

• 7 mm - inside diameter d1
• 1.8 mm - cross-section diameter d2

The calculated outside diameter is:

7 mm + 2 x 1.8 mm = 10.6 mm

Both dimensions must be considered when identifying a replacement O-ring.

The description "7 mm O-ring" alone is insufficient because O-rings with the same inside diameter can be manufactured with different cross-sections.

For this product, the complete dimensional identification is:

7x1.8 mm

What does O-Ring 7x1.8 VMQ 70 ShA mean?

The product designation can be interpreted as follows:

7 - nominal inside diameter of 7 mm.

1.8 - nominal O-ring cross-section diameter of 1.8 mm.

VMQ - silicone rubber elastomer.

70 ShA - nominal material hardness of 70 Shore A.

100 pcs - quantity supplied in the package.

The complete technical identification should therefore include the dimensions, material and hardness:

O-Ring 7x1.8 mm VMQ 70 ShA

VMQ or MVQ - which designation is correct?

The technical designation used for this silicone rubber family is:

VMQ

Therefore, the recommended English product name is:

O-Ring 7x1.8 VMQ 70 ShA Silicone - 100 pcs

The spelling MVQ may occur in customer searches and commercial descriptions, so it can be included naturally as an alternative search reference.

For the product name and technical specification, however, VMQ is recommended.

VMQ silicone rubber

VMQ belongs to the silicone rubber family of elastomers used for O-rings and other sealing elements.

Characteristic properties associated with VMQ silicone materials include:

• excellent heat resistance
• excellent cold flexibility
• good resistance to weathering
• good resistance to ozone
• good resistance to UV radiation
• useful dielectric properties

These characteristics describe the VMQ material family. They should not be interpreted as guaranteed numerical performance values for every VMQ compound.

Different formulations can have different:

• temperature limits
• chemical resistance
• mechanical properties
• compression set
• tear resistance
• certifications and approvals

Therefore, the designation VMQ 70 ShA identifies the material family and nominal hardness but does not represent a complete compound specification.

What does 70 ShA mean?

70 ShA means that the elastomer has a nominal hardness of 70 on the Shore A hardness scale.

Hardness affects how the O-ring deforms when compressed inside the sealing groove.

However, hardness alone does not determine:

• chemical compatibility
• operating temperature
• abrasion resistance
• service life
• compatibility with oils or fuels
• food-contact approval
• suitability for a specific application

Two O-rings with a nominal hardness of 70 ShA may have substantially different properties if they are manufactured from different elastomers or different formulations of the same elastomer.

Operating temperature of VMQ 70 ShA

VMQ silicone rubber is known for retaining useful elastomeric properties across a broad temperature range.

However, there is no single guaranteed temperature range that can automatically be assigned to every VMQ 70 ShA O-ring.

The actual limits depend on factors including:

• exact compound formulation
• operating medium
• exposure duration
• sealing-system design
• static or dynamic operation
• application conditions

For this reason, no unverified minimum or maximum operating temperature is assigned to this specific O-Ring 7x1.8 VMQ 70 ShA.

For engineering applications where temperature limits are critical, the material data sheet for the exact VMQ compound should be consulted.

Resistance to ozone, UV and weathering

VMQ silicone rubber as a material family is characterized by good resistance to:

• ozone
• UV radiation
• weathering
• oxygen

These properties distinguish silicone from several other commonly used sealing elastomers.

Actual service life still depends on the specific formulation, mechanical loading, temperature, environment and sealing-system design.

Construction and operating principle

O-Ring 7x1.8 VMQ has a simple geometric construction: it is a closed elastomeric ring with a circular cross-section of 1.8 mm.

The O-ring is installed in an appropriately dimensioned sealing groove.

When the mating components are assembled, the 1.8 mm cross-section is compressed. Elastic deformation of the VMQ material creates contact pressure against the mating surfaces, producing the sealing effect.

Effective sealing depends on the complete system, including:

• O-ring dimensions
• groove geometry
• compression
• O-ring stretch
• mating surface condition
• operating pressure
• temperature
• medium
• static or dynamic operation

For this reason, the dimensions alone are not sufficient to determine whether an O-ring is suitable for a particular application.

O-Ring 7x1.8 VMQ vs NBR

An:

O-Ring 7x1.8 VMQ 70 ShA

and an:

O-Ring 7x1.8 NBR 70 ShA

can have identical dimensions and nominal hardness while being manufactured from completely different elastomers.

VMQ is silicone rubber.

NBR is nitrile rubber.

The two material families have different thermal, chemical and mechanical characteristics.

Therefore, identical dimensions of 7x1.8 mm and the same nominal hardness of 70 ShA do not guarantee material interchangeability.

O-Ring 7x1.8 VMQ vs FKM

The same principle applies when comparing VMQ and FKM O-rings.

An O-Ring 7x1.8 VMQ and an O-Ring 7x1.8 FKM may fit the same groove dimensionally, but their material characteristics can differ significantly.

Before changing the elastomer, verify:

• operating medium
• operating temperature
• pressure
• static or dynamic operation
• environmental conditions
• application requirements

Material selection should not be based on dimensions alone.

Chemical compatibility of VMQ

VMQ should not be considered universally resistant to all oils, fuels, solvents or other chemical media.

Chemical compatibility depends on the exact compound formulation and operating conditions.

Compatibility should be checked particularly when the seal is exposed to:

• oils
• fuels
• greases
• solvents
• acids
• alkalis
• alcohols
• water and steam
• gases
• industrial process fluids

If fluid compatibility is critical to the reliability or safety of the application, the material specification for the exact VMQ compound should be verified before installation.

Is a VMQ silicone O-ring food safe?

The designation VMQ alone does not confirm food-contact approval.

Specific silicone compounds are available for food, pharmaceutical and medical applications, but regulatory compliance applies to the particular compound or finished product.

Therefore, this O-Ring 7x1.8 VMQ 70 ShA should not automatically be described as compliant with FDA, EC 1935/2004 or medical requirements without supporting documentation.

O-Ring 7x1.8 vs O-Ring 7x2

O-Ring 7x1.8 mm is not the same size as O-Ring 7x2 mm.

Both have an inside diameter of 7 mm, but their cross-sections differ.

O-Ring 7x1.8 mm:

• inside diameter 7 mm
• cross-section 1.8 mm
• calculated outside diameter 10.6 mm

O-Ring 7x2 mm:

• inside diameter 7 mm
• cross-section 2 mm
• calculated outside diameter 11 mm

The difference in cross-section affects groove filling and sealing compression.

These two sizes should not be interchanged without checking the groove dimensions and sealing-system design.

Selection and interchangeability

Before purchasing or replacing an O-Ring 7x1.8 VMQ, verify:

• inside diameter 7 mm
• cross-section 1.8 mm
• material VMQ
• nominal hardness 70 ShA
• groove dimensions
• required compression
• permissible stretch
• operating temperature
• operating medium
• pressure
• static or dynamic operating conditions

Identical dimensions do not automatically mean complete interchangeability.

For example, 7x1.8 mm O-rings manufactured from VMQ, NBR, EPDM and FKM can have identical geometry but substantially different material characteristics.

Applications

O-Ring 7x1.8 VMQ can be used as a sealing element in correctly designed grooves where the characteristics of the specific silicone compound meet the operating requirements.

O-rings as a sealing type can be used in static applications and, with appropriate sealing-system design, in certain dynamic applications.

No specific machine, vehicle, gearbox, engine or OEM application is assigned to this SKU without supporting technical documentation.

Installation and handling

Before installation, inspect both the O-ring and the sealing groove.

The groove and mating surfaces should be clean and free from contamination, burrs, sharp edges and damage that could cut or scratch the elastomer.

The O-ring should not be twisted during installation.

Avoid excessive stretching and do not use sharp installation tools that could damage its surface.

If assembly lubrication is required, verify that the lubricant is compatible with both the VMQ compound and the operating medium.

O-rings should be stored away from excessive heat, direct UV exposure, contamination and conditions that could damage the elastomer.

Alternative designations and search references

Natural references for this product include:

O-Ring 7x1.8 VMQ 70 ShA

7x1.8 VMQ O-Ring

O-Ring 7x1.8 MVQ 70 ShA

7x1.8 silicone O-ring

Silicone O-Ring 7x1.8 mm

VMQ 70 Shore O-Ring 7x1.8

7 mm ID 1.8 mm CS O-Ring

7mm x 1.8mm silicone O-ring

O-Ring 7x1.8 VMQ 100 pcs

7x1.8 silicone sealing ring

No OEM or cross-reference numbers are stated because none have been confirmed for this product.

FAQ

What are the dimensions of O-Ring 7x1.8 VMQ 70 ShA?

The O-ring has a 7 mm inside diameter and a 1.8 mm cross-section. Its calculated outside diameter is 10.6 mm.

What is VMQ?

VMQ is the technical designation for a family of silicone rubber elastomers used in O-rings and other sealing components.

What does 70 ShA mean?

It indicates a nominal elastomer hardness of 70 on the Shore A scale.

VMQ or MVQ - which designation is correct?

VMQ is the recommended technical designation for this silicone rubber family. MVQ may occur as an alternative search spelling, but VMQ should be used in the technical specification.

What is the operating temperature of a VMQ 70 ShA O-ring?

The exact operating range cannot be determined from VMQ 70 ShA alone. Temperature limits depend on the exact compound formulation, operating medium and application conditions.

Can O-Ring 7x1.8 VMQ replace O-Ring 7x1.8 NBR?

Not automatically. The dimensions may be identical, but VMQ and NBR have different material properties. Operating medium, temperature and other application requirements must be checked.

Can a 7x1.8 O-ring be replaced with a 7x2 O-ring?

Not without checking the groove. The 7x2 O-ring has a larger cross-section and outside diameter, which changes groove filling and compression.

Is this O-ring approved for food contact?

The VMQ designation alone does not confirm food-contact approval. Compliance must be supported by documentation for the exact compound or finished product.

O-Ring 7x1.8 VMQ 70 ShA - key information

O-Ring 7x1.8 VMQ 70 ShA is a silicone sealing ring with a 7 mm inside diameter and 1.8 mm cross-section. Its calculated outside diameter is 10.6 mm. VMQ identifies silicone rubber, while 70 ShA specifies the nominal Shore A hardness. The product is supplied in a package containing 100 pieces.