2PCS MR3040 Shaft Bearings 30x40x7 & 30x40x6 – 2RS Sealed

2PCS MR3040 Shaft Bearings – 30x40x7 & 30x40x6 (2RS Sealed)

Get precision-engineered bearing steel shaft bearings in a convenient 2-piece set. Whether you need the 30x40x7mm or the 30x40x6mm variant, these sealed miniature bearings deliver smooth, consistent rotation and long-lasting performance across a wide range of mechanical and DIY applications.

Manufactured from high-quality bearing steel, these double-rubber-sealed (2RS) bearings are designed to keep contaminants out and lubrication in — making them ideal for use in motors, robotics, RC vehicles, skateboards, precision machinery, and more.

Made in Mainland China.

Specifications

MR3040H7 / 30x40x7

• Inner Diameter: 30mm
• Outer Diameter: 40mm
• Thickness: 7mm
• Seal Type: 2RS (Double Rubber Sealed)
• Material: Bearing Steel
• Compatible Models: MR3040H7-2RS, 30406, 30407, 30426, 30427, 30467

MR3040H6 / 30x40x6

• Inner Diameter: 30mm
• Outer Diameter: 40mm
• Thickness: 6mm
• Seal Type: 2RS (Double Rubber Sealed)
• Material: Bearing Steel
• Compatible Models: MR3040H6, 30x42x6

Key Features

• ✅ Premium Bearing Steel – High hardness and wear resistance for extended service life
• ✅ Double Rubber Seals (2RS) – Effectively blocks dust, debris, and moisture
• ✅ Pre-Lubricated – Ready to install straight out of the box
• ✅ Precise Dimensions – Consistent tolerances for smooth, low-vibration operation
• ✅ Versatile Fit – Suitable for motors, 3D printers, RC models, industrial equipment, and more
• ✅ 2-Piece Set – Great value with two bearings per order

What's Included

• 1× MR3040H7-2RS Bearing (30x40x7mm)
• 1× MR3040H6 Bearing (30x40x6mm)

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Frequently Asked Questions

Q: What does the "2RS" designation mean on these MR3040 bearings?

A: "2RS" stands for Double Rubber Sealed — both sides of the bearing are fitted with rubber seals. This design keeps grease inside and prevents dust, dirt, and moisture from entering the bearing, resulting in longer service life and more reliable performance in demanding environments.

Q: Are these bearings interchangeable with models 30406, 30407, 30426, 30427, and 30467?

A: Yes. The MR3040H7-2RS bearing (30x40x7mm) is compatible with a range of equivalent model numbers including 30406, 30407, 30426, 30427, and 30467. Always verify the inner diameter (30mm), outer diameter (40mm), and thickness (7mm) match your application before installing.

Q: What applications are these 30x40 shaft bearings suitable for?

A: These miniature shaft bearings are widely used in 3D printers, RC cars and drones, electric motors, robotics, skateboards, bicycles, and various industrial or DIY machinery where a precise 30mm bore diameter is required.

Q: Do these bearings come pre-lubricated and ready to install?

A: Yes. Both the 30x40x7mm and 30x40x6mm bearings in this set are pre-greased and sealed, so they are ready to install immediately upon arrival without any additional lubrication needed.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.