What Is a Micro Push-Pull Solenoid?

A Micro Push-Pull Solenoid is a compact electromagnetic actuator designed to create linear motion through the use of an energized coil. Structurally, it consists of:

• A copper-wound solenoid coil

• A central iron armature/plunger

• A return spring (in many models)

• A small cylindrical or rectangular housing

When electrical current flows through the solenoid coil, a magnetic field is generated, which pulls the plunger into the coil’s center. Because the plunger has two usable ends, the device can provide either pulling or pushing motion—hence the name push-pull solenoid.

Why “Micro”?

“Micro” indicates that the solenoid is very small—typically designed for applications where space is limited.
For example, the type you described has:

• Body length around 40 mm

• A captive plunger (preventing it from falling out)

• A strong return spring to automatically reset the plunger when power is removed

How It Works (Simple Operation)

1. Apply DC voltage (e.g., 12V):
   The coil generates magnetic force, pulling the plunger inward.

2. Remove voltage:
   The return spring pushes the plunger back to its original position.

This makes the operation straightforward and reliable.

Advantages of Micro Push-Pull Solenoids

• ✔ Very compact—easy to fit in tight spaces

• ✔ Dual-action capability (can push or pull)

• ✔ Captive armature—won’t fall out like some low-cost solenoids

• ✔ Integrated return spring—automatic reset without extra mechanisms

• ✔ Convenient mounting tabs for easy installation

How it works

A pull-type solenoid operates based on the electromagnetic force. It consists of a coil of wire wrapped around a bobbin. When current passes through the copper coil, it generates a magnetic field. This field exerts a force on a ferromagnetic plunger (or armature) within the coil. In a pull-type solenoid, the magnetic field pulls the plunger into the coil, producing linear motion. When the current is turned off, a built in return spring or other mechanical mechanism pushes the plunger back to its original position, deactivating the solenoid.

The structure

Solenoid Coil: A wound component that generates the necessary magnetic field when an electric current is applied. The solenoid coil is typically made of copper wire and is wound helically around a cylinder.

Plunger: The movable part of a solenoid, typically made of a ferromagnetic material such as iron or a magnetic alloy. The plunger is designed to be pulled into the coil when the solenoid is powered on.

Return Spring: This component is used to return the plunger to its original position when the current to the coil is interrupted. The spring is usually located at one end of the plunger and is compressed when the plunger is pulled into the coil.

Frame or Housing: Provides mechanical support and protection for the coil and plunger. The frame can be open or closed, depending on the application requirements.

Application

Locking system: Pull solenoids are commonly used in electric locks. The pulling force of the solenoid can be used to unlock or lock the lock, thus achieving remote or automated access control.

Industrial Automation: They are used in various industrial automation systems to perform tasks such as moving mechanical parts, operating valves, and actuating switches. For example, in a production line, a pull solenoid can be used to move a part to a specific position.

Robotics: Pull solenoids can be used to actuate the joints or limbs of robots, providing the linear motion necessary for precise manipulation and locomotion.

Vending machines: In vending machines, pull solenoids can be used to dispense merchandise. For example, when a user purchases an item, the solenoid pulls a mechanism that releases the selected item.

Pinball Machines: They are used to pull the firing lever in pinball machines, providing the force needed to launch the ball.

 Basic accuracy dimension requirements for automotive car stamping part

• Flatness: The plane part should be flat, and its flatness tolerance must meet the design requirements. For example, the flatness requirements of the body outer covering parts are high, otherwise it will affect the appearance flatness after assembly.
• Versatility: For some stamping parts with vertical installation requirements, such as door pillars, frame longitudinal beams, etc., the verticality tolerance should be within the specified range to ensure accuracy and stability after installation.
• Contour: The outer contour size and shape of the stamping parts should be consistent with the design drawings, and the contour tolerance must meet the assembly and use requirements. For example, the contour tolerance of the folding surface of the four doors and two covers should meet the corresponding standards.

Material and coating requirements

Materials for Automotive stamping part requirements  

• Automotive bodycovering parts: such as doors, hoods, trunk lids, roofs, etc., ithave large sizes and complex shapes, and high requirements for surface quality and dimensional accuracy.
• Frame and chassis parts:including beams, subframes, suspension arms, torsion beams, etc. These parts need to withstand large loads, so the strength and stiffness of the materials are required to be high.
• Engine parts:such as cylinder blocks, cylinder heads, pistons, connecting rods, etc., have harsh working environments and need to withstand high temperatures, high pressures and high-speed impacts, and have high requirements for the heat resistance, wear resistance and corrosion resistance of the materials.
• Interior parts and accessories: such as seat frames, instrument panel brackets, armrests, buckles, etc., these stamping parts usually have certain requirements for appearance quality and comfort, and need to have good surface treatment and assembly performance.

Features

• High dimensional accuracy: Through die stamping processing, the dimensions of the stamping parts in the same batch can be guaranteed to be uniform and consistent, with good interchangeability, and general assembly and use requirements can be met without further machining.Good surface quality: The surface of the material is not damaged during the stamping process, and the appearance is smooth and beautiful, which provides convenient conditions for surface painting, electroplating, phosphating and other surface treatments.

 Dimension Control Requirements:

Dimension and shape accuracy: The dimensional deviation of automobile hardware stampings should be controlled within a strict tolerance range, and the shape should meet the design requirements to ensure accurate assembly with other parts and the quality stability of the whole vehicle.

• Surface quality: The surface should be smooth and flat, without burrs, scratches, cracks and other defects to ensure the surface treatment effect and appearance quality, while avoiding wear or damage to other parts.
• Material properties: According to different use parts and functional requirements, the material should have corresponding mechanical properties, such as strength, hardness, toughness, fatigue limit, etc., as well as good processing performance and weldability.
• Reliability and durability: Automobile hardware stampings must withstand various complex working conditions and environmental conditions throughout the service life of the vehicle, so they need to have high reliability and durability and be able to work stably for a long time.
• Environmental protection and recyclability: With the improvement of environmental awareness, the materials of automobile hardware stampings should be recyclable as much as possible, and the pollution to the environment should be reduced during the production process.
• High production efficiency: Stamping production lines usually use automated and semi-automated equipment, such as multi-station progressive dies, etc., which can complete multiple stamping processes on one press, with fast production speed and can be mass-produced in a short time.

• Light weight and high strength: Under the premise of low material consumption, the parts manufactured by stamping are light in weight and have good rigidity, and after the sheet material is plastically deformed, the internal structure of the metal is improved, so that the strength of the metal stamping parts is improved.

Appearance requirements

• No obvious defects: The surface should be free of obvious defects such as scratches, abrasions, pits, convex hulls, cracks, wrinkles, ripples, etc. These defects will seriously affect the appearance of the car.
• Clear edges: For stamping parts with decorative edges or edges, such as doors, hoods, etc., the edges are required to be clear, smooth, symmetrical and evenly transitioned, and the edges should be matched, and unevenness is not allowed.
• Surface roughness: It needs to be controlled within a certain range. Generally, it is kept at a minimum through measures such as sheet quality, stamping production process and material management to ensure the smoothness and glossiness of the surface2.

Cleanliness surface requirements

• No oil stains: There should be no oil stains, grease and other stains on the surface of the stamping parts, otherwise it will affect the adhesion of subsequent surface treatment processes, such as painting and electroplating.
• No impurities: There should be no dust, iron filings, welding slag and other impurities on the surface. These impurities may fall off during use, causing component wear or affecting the normal operation of other systems.
• No rust: There should be no rust on the surface of the stamping parts, especially for some parts that are exposed to the external environment for a long time, such as chassis parts, body outer covering parts, etc. Rust will reduce the strength and service life of the parts.

      Dimensional requirements for automotive stamping part

• Flatness: The plane part should be flat, and its flatness tolerance must meet the design requirements. For example, the flatness requirements of the body outer covering parts are high, otherwise it will affect the appearance flatness after assembly.
• Versatility: For some stamping parts with vertical installation requirements, such as door pillars, frame longitudinal beams, etc., the verticality tolerance should be within the specified range to ensure accuracy and stability after installation.
• Contour: The outer contour size and shape of the stamping parts should be consistent with the design drawings, and the contour tolerance must meet the assembly and use requirements. For example, the contour tolerance of the folding surface of the four doors and two covers should meet the corresponding standards.

Materials for Automotive stamping part requirements  

• Automotive bodycovering parts: such as doors, hoods, trunk lids, roofs, etc., ithave large sizes and complex shapes, and high requirements for surface quality and dimensional accuracy.
• Frame and chassis parts:including beams, subframes, suspension arms, torsion beams, etc. These parts need to withstand large loads, so the strength and stiffness of the materials are required to be high.
• Engine parts:such as cylinder blocks, cylinder heads, pistons, connecting rods, etc., have harsh working environments and need to withstand high temperatures, high pressures and high-speed impacts, and have high requirements for the heat resistance, wear resistance and corrosion resistance of the materials.
• Interior parts and accessories: such as seat frames, instrument panel brackets, armrests, buckles, etc., these stamping parts usually have certain requirements for appearance quality and comfort, and need to have good surface treatment and assembly performance.

Features

• High dimensional accuracy: Through die stamping processing, the dimensions of the stamping parts in the same batch can be guaranteed to be uniform and consistent, with good interchangeability, and general assembly and use requirements can be met without further machining.Good surface quality: The surface of the material is not damaged during the stamping process, and the appearance is smooth and beautiful, which provides convenient conditions for surface painting, electroplating, phosphating and other surface treatments.

  Dimension Control Requirements:

Dimension and shape accuracy: The dimensional deviation of automobile hardware stampings should be controlled within a strict tolerance range, and the shape should meet the design requirements to ensure accurate assembly with other parts and the quality stability of the whole vehicle.

• Surface quality: The surface should be smooth and flat, without burrs, scratches, cracks and other defects to ensure the surface treatment effect and appearance quality, while avoiding wear or damage to other parts.
• Material properties: According to different use parts and functional requirements, the material should have corresponding mechanical properties, such as strength, hardness, toughness, fatigue limit, etc., as well as good processing performance and weldability.
• Reliability and durability: Automobile hardware stampings must withstand various complex working conditions and environmental conditions throughout the service life of the vehicle, so they need to have high reliability and durability and be able to work stably for a long time.
• Environmental protection and recyclability: With the improvement of environmental awareness, the materials of automobile hardware stampings should be recyclable as much as possible, and the pollution to the environment should be reduced during the production process.
• High production efficiency: Stamping production lines usually use automated and semi-automated equipment, such as multi-station progressive dies, etc., which can complete multiple stamping processes on one press, with fast production speed and can be mass-produced in a short time.

• Light weight and high strength: Under the premise of low material consumption, the parts manufactured by stamping are light in weight and have good rigidity, and after the sheet material is plastically deformed, the internal structure of the metal is improved, so that the strength of the metal stamping parts is improved.

Appearance requirements

• No obvious defects: The surface should be free of obvious defects such as scratches, abrasions, pits, convex hulls, cracks, wrinkles, ripples, etc. These defects will seriously affect the appearance of the car.
• Clear edges: For stamping parts with decorative edges or edges, such as doors, hoods, etc., the edges are required to be clear, smooth, symmetrical and evenly transitioned, and the edges should be matched, and unevenness is not allowed.
• Surface roughness: It needs to be controlled within a certain range. Generally, it is kept at a minimum through measures such as sheet quality, stamping production process and material management to ensure the smoothness and glossiness of the surface2.

Cleanliness surface requirements

• No oil stains: There should be no oil stains, grease and other stains on the surface of the stamping parts, otherwise it will affect the adhesion of subsequent surface treatment processes, such as painting and electroplating.
• No impurities: There should be no dust, iron filings, welding slag and other impurities on the surface. These impurities may fall off during use, causing component wear or affecting the normal operation of other systems.
• No rust: There should be no rust on the surface of the stamping parts, especially for some parts that are exposed to the external environment for a long time, such as chassis parts, body outer covering parts, etc. Rust will reduce the strength and service life of the parts.

 Basic Dimensional requirements for automotive Metal stamping part

• Flatness: The plane part should be flat, and its flatness tolerance must meet the design requirements.  
• Versatility: For some stamping parts with vertical installation requirements, such as door pillars, frame longitudinal beams, etc., 
• Contour: The outer contour size and shape of the stamping parts should be consistent with the design drawings, and the contour tolerance must meet the assembly and use requirements. For example, the contour tolerance of the folding surface of the four doors and two covers should meet the corresponding standards.

Materials for Automotive stamping part requirements  

• Automotive bodycovering parts: such as doors, hoods, trunk lids, roofs, etc., ithave large sizes and complex shapes, and high requirements for surface quality and dimensional accuracy.
• Frame and chassis parts:including beams, subframes, suspension arms, torsion beams, etc. These parts need to withstand large loads, so the strength and stiffness of the materials are required to be high.
• Engine parts:such as cylinder blocks, cylinder heads, pistons, connecting rods, etc., have harsh working environments and need to withstand high temperatures, high pressures and high-speed impacts, and have high requirements for the heat resistance, wear resistance and corrosion resistance of the materials.
• Interior parts and accessories: such as seat frames, instrument panel brackets, armrests, buckles, etc., these stamping parts usually have certain requirements for appearance quality and comfort, and need to have good surface treatment and assembly performance.

Features

• High dimensional accuracy: Through die stamping processing, the dimensions of the stamping parts in the same batch can be guaranteed to be uniform and consistent, with good interchangeability, and general assembly and use requirements can be met without further machining.Good surface quality: The surface of the material is not damaged during the stamping process, and the appearance is smooth and beautiful, which provides convenient conditions for surface painting, electroplating, phosphating and other surface treatments.

 Dimension Control Requirements:

Dimension and shape accuracy: The dimensional deviation of automobile hardware stampings should be controlled within a strict tolerance range, and the shape should meet the design requirements to ensure accurate assembly with other parts and the quality stability of the whole vehicle.

• Surface quality: The surface should be smooth and flat, without burrs, scratches, cracks and other defects to ensure the surface treatment effect and appearance quality, while avoiding wear or damage to other parts.
• Material properties: According to different use parts and functional requirements, the material should have corresponding mechanical properties, such as strength, hardness, toughness, fatigue limit, etc., as well as good processing performance and weldability.
• Reliability and durability: Automobile hardware stampings must withstand various complex working conditions and environmental conditions throughout the service life of the vehicle, so they need to have high reliability and durability and be able to work stably for a long time.
• Environmental protection and recyclability: With the improvement of environmental awareness, the materials of automobile hardware stampings should be recyclable as much as possible, and the pollution to the environment should be reduced during the production process.
• High production efficiency: Stamping production lines usually use automated and semi-automated equipment, such as multi-station progressive dies, etc., which can complete multiple stamping processes on one press, with fast production speed and can be mass-produced in a short time.
• Light weight and high strength: Under the premise of low material consumption, the parts manufactured by stamping are light in weight and have good rigidity, and after the sheet material is plastically deformed, the internal structure of the metal is improved, so that the strength of the metal stamping parts is improved.

Appearance requirements

• No obvious defects: The surface should be free of obvious defects such as scratches, abrasions, pits, convex hulls, cracks, wrinkles, ripples, etc. These defects will seriously affect the appearance of the car.
• Clear edges: For stamping parts with decorative edges or edges, such as doors, hoods, etc., the edges are required to be clear, smooth, symmetrical and evenly transitioned, and the edges should be matched, and unevenness is not allowed.
• Surface roughness: It needs to be controlled within a certain range. Generally, it is kept at a minimum through measures such as sheet quality, stamping production process and material management to ensure the smoothness and glossiness of the surface2.

Cleanliness surface requirements

• No oil stains: There should be no oil stains, grease and other stains on the surface of the stamping parts, otherwise it will affect the adhesion of subsequent surface treatment processes, such as painting and electroplating.
• No impurities: There should be no dust, iron filings, welding slag and other impurities on the surface. These impurities may fall off during use, causing component wear or affecting the normal operation of other systems.
• No rust: There should be no rust on the surface of the stamping parts, especially for some parts that are exposed to the external environment for a long time, such as chassis parts, body outer covering parts, etc. Rust will reduce the strength and service life of the parts.

 Basic Dimensional accuracy requirements for automotive stamping part

• Flatness: The plane part should be flat, and its flatness tolerance must meet the design requirements. For example, the flatness requirements of the body outer covering parts are high, otherwise it will affect the appearance flatness after assembly.
• Versatility: For some stamping parts with vertical installation requirements, such as door pillars, frame longitudinal beams, etc., the verticality tolerance should be within the specified range to ensure accuracy and stability after installation.
• Contour: The outer contour size and shape of the stamping parts should be consistent with the design drawings, and the contour tolerance must meet the assembly and use requirements. For example, the contour tolerance of the folding surface of the four doors and two covers should meet the corresponding standards.

Material and coating requirements

Materials for Automotive stamping part requirements  

• Automotive bodycovering parts: such as doors, hoods, trunk lids, roofs, etc., ithave large sizes and complex shapes, and high requirements for surface quality and dimensional accuracy.
• Frame and chassis parts:including beams, subframes, suspension arms, torsion beams, etc. These parts need to withstand large loads, so the strength and stiffness of the materials are required to be high.
• Engine parts:such as cylinder blocks, cylinder heads, pistons, connecting rods, etc., have harsh working environments and need to withstand high temperatures, high pressures and high-speed impacts, and have high requirements for the heat resistance, wear resistance and corrosion resistance of the materials.
• Interior parts and accessories: such as seat frames, instrument panel brackets, armrests, buckles, etc., these stamping parts usually have certain requirements for appearance quality and comfort, and need to have good surface treatment and assembly performance.

Features

• High dimensional accuracy: Through die stamping processing, the dimensions of the stamping parts in the same batch can be guaranteed to be uniform and consistent, with good interchangeability, and general assembly and use requirements can be met without further machining.Good surface quality: The surface of the material is not damaged during the stamping process, and the appearance is smooth and beautiful, which provides convenient conditions for surface painting, electroplating, phosphating and other surface treatments.

  Dimension Control Requirements:

Dimension and shape accuracy: The dimensional deviation of automobile hardware stampings should be controlled within a strict tolerance range, and the shape should meet the design requirements to ensure accurate assembly with other parts and the quality stability of the whole vehicle.

• Surface quality: The surface should be smooth and flat, without burrs, scratches, cracks and other defects to ensure the surface treatment effect and appearance quality, while avoiding wear or damage to other parts.
• Material properties: According to different use parts and functional requirements, the material should have corresponding mechanical properties, such as strength, hardness, toughness, fatigue limit, etc., as well as good processing performance and weldability.
• Reliability and durability: Automobile hardware stampings must withstand various complex working conditions and environmental conditions throughout the service life of the vehicle, so they need to have high reliability and durability and be able to work stably for a long time.
• Environmental protection and recyclability: With the improvement of environmental awareness, the materials of automobile hardware stampings should be recyclable as much as possible, and the pollution to the environment should be reduced during the production process.
• High production efficiency: Stamping production lines usually use automated and semi-automated equipment, such as multi-station progressive dies, etc., which can complete multiple stamping processes on one press, with fast production speed and can be mass-produced in a short time.

• Light weight and high strength: Under the premise of low material consumption, the parts manufactured by stamping are light in weight and have good rigidity, and after the sheet material is plastically deformed, the internal structure of the metal is improved, so that the strength of the metal stamping parts is improved.

Appearance requirements

• No obvious defects: The surface should be free of obvious defects such as scratches, abrasions, pits, convex hulls, cracks, wrinkles, ripples, etc. These defects will seriously affect the appearance of the car.
• Clear edges: For stamping parts with decorative edges or edges, such as doors, hoods, etc., the edges are required to be clear, smooth, symmetrical and evenly transitioned, and the edges should be matched, and unevenness is not allowed.
• Surface roughness: It needs to be controlled within a certain range. Generally, it is kept at a minimum through measures such as sheet quality, stamping production process and material management to ensure the smoothness and glossiness of the surface2.

Cleanliness surface requirements

• No oil stains: There should be no oil stains, grease and other stains on the surface of the stamping parts, otherwise it will affect the adhesion of subsequent surface treatment processes, such as painting and electroplating.
• No impurities: There should be no dust, iron filings, welding slag and other impurities on the surface. These impurities may fall off during use, causing component wear or affecting the normal operation of other systems.
• No rust: There should be no rust on the surface of the stamping parts, especially for some parts that are exposed to the external environment for a long time, such as chassis parts, body outer covering parts, etc. Rust will reduce the strength and service life of the parts.

 The basic requirements for solenoid metal stamping parts?

Dimensional accuracy requirements: The dimensional tolerance is usually controlled within 0.05mm to ensure that the difference between the actual size of the part and the designed size is within the allowable range to ensure the assembly accuracy and performance of the electromagnet.

Geometric shape accuracy requirements: It must meet high requirements such as flatness, roundness, verticality, etc. For example, the shape accuracy of the electromagnet frame affects the coordination with other parts and the overall performance.

Surface quality requirements: The surface should be free of obvious scratches, bumps, bubbles and other defects, and should have a certain degree of smoothness to prevent affecting the appearance and insulation, heat dissipation and other properties of the electromagnet, and also provide a good foundation for subsequent surface treatments such as electroplating.

Material performance requirements: According to the use environment and performance requirements of the electromagnet, select appropriate materials, such as materials with good electrical conductivity, magnetic conductivity, strength and toughness. At the same time, the material should have good stamping properties, such as crack resistance, mold adhesion, shape stability, etc.

Mold design requirement: The mold precision should be high to ensure the size and shape accuracy of the stamping parts; the structural design should be reasonable to facilitate manufacturing, maintenance and debugging to improve production efficiency and reduce costs.

Assembly requirement: Stamping parts should be easy to assemble and repair, and can be quickly and accurately assembled with other parts of the electromagnet to improve production efficiency and product quality.

 The basic requirements for solenoid metal stamping parts?

Dimensional accuracy requirements: The dimensional tolerance is usually controlled within 0.05mm to ensure that the difference between the actual size of the part and the designed size is within the allowable range to ensure the assembly accuracy and performance of the electromagnet.

Geometric shape accuracy requirements: It must meet high requirements such as flatness, roundness, verticality, etc. For example, the shape accuracy of the electromagnet frame affects the coordination with other parts and the overall performance.

Surface quality requirements: The surface should be free of obvious scratches, bumps, bubbles and other defects, and should have a certain degree of smoothness to prevent affecting the appearance and insulation, heat dissipation and other properties of the electromagnet, and also provide a good foundation for subsequent surface treatments such as electroplating.

Material performance requirements: According to the use environment and performance requirements of the electromagnet, select appropriate materials, such as materials with good electrical conductivity, magnetic conductivity, strength and toughness. At the same time, the material should have good stamping properties, such as crack resistance, mold adhesion, shape stability, etc.

Mold design requirement: The mold precision should be high to ensure the size and shape accuracy of the stamping parts; the structural design should be reasonable to facilitate manufacturing, maintenance and debugging to improve production efficiency and reduce costs.

 Assembly requirement: Stamping parts should be easy to assemble and repair, and can be quickly and accurately assembled with other parts of the electromagnet to improve production efficiency and product quality.