Thin Section Ball Bearings

Thin Section Ball Bearings

Thin section ball bearings save space and weight in compact machines. Their cross-section stays small even when the bore gets large. This lets designers fit smooth, accurate rotation into tight housings.

LYDL supplies metric thin section ball bearings for automation, robotics, medical equipment, and other precision applications. This page explains the types, sizes, options, and selection points so you can choose the right bearing.

What Are Thin Section Ball Bearings?

A thin section ball bearing has a narrow ring wall and a small radial cross-section compared with its bore. The rings are thin, the balls are small, and the whole bearing takes up very little room.

In many thin section series, the cross-section stays the same as the bore grows. A bearing with a 100 mm bore and one with a 200 mm bore can share the same profile. This is why they are also called constant section bearings.

Standard ball bearings grow thicker as the bore increases. That adds weight and requires larger housings. Thin section bearings avoid this problem.

Benefits of Thin Section Bearings

• Space saving. A slim profile fits compact housings and hollow shaft designs.
• Lightweight. Less steel means lower rotating mass. This helps robots, drones, and moving arms.
• Low friction. Small balls and a light design give low running torque.
• Smooth, quiet running. Good for medical devices and measuring equipment.
• Design flexibility. One cross-section can serve many bore sizes in the same product family.
• Large bore options. Hollow shafts can carry cables, hoses or optical paths through the center.

Types of Thin Section Ball Bearings

Thin section bearings come in three main contact designs. Each handles load differently.

Radial contact bearings (Type C)

Radial contact bearings have deep raceway grooves. They carry radial loads well. They also take light axial loads in both directions. This is the most common type for general automation and light to medium duty use.

Angular contact bearings (Type A)

Angular contact bearings carry combined radial and axial loads. The axial load works in one direction only. They are often used in pairs or sets to handle thrust from both sides and to set preload.

Four-point contact bearings (Type X)

Four-point contact bearings take radial load and axial load from both directions in one bearing. They work like a double row angular contact bearing. This saves space when a single bearing must hold a shaft against thrust either way.

LYDL’s range on this page focuses on metric thin section radial contact ball bearings. For angular contact or four-point contact needs, send us your drawing and load details.

Metric Thin Section Bearing Series

Metric thin section bearings follow standard dimension series. The common ones are the 618 and 619 series. These are thin versions of the more familiar 6000 and 6200 series.

The table below shows reference dimensions for the 618 series. Use it to check basic fit and envelope size.

Need a larger bore, a different cross-section or a non-standard size? We can quote custom dimensions on request.

Open vs Shielded Thin Section Bearings

The right closure depends on your environment and your maintenance plan.

• Open bearings give the lowest friction. They suit clean environments. They also allow easy cleaning and relubrication.
• Shielded bearings have metal shields on one or both sides. They keep out larger particles and hold grease in. Friction stays low because the shield does not touch the inner ring.
• Sealed bearings use rubber seals. They block dust and moisture better. Torque is a little higher than with shields.

If the bearing runs at high speed, shields are usually a good balance. If the housing is dirty or washed down, choose seals.

Materials, Cages and Precision

Ring and ball material. Chrome steel is the standard choice and gives good hardness and fatigue life. Stainless steel suits corrosive or humid conditions. Ceramic balls can be requested for special speed or electrical insulation needs.

Cage type. Pressed steel cages are the common option. Other cage materials can suit higher speed or special temperature ranges.

Precision grade. Light, accurate machines need tight running accuracy. State the grade you need when you request a quote, so the rings and balls are made to match it.

Internal clearance. Normal clearance suits most uses. Smaller or larger clearance can be chosen to control stiffness, noise, and heat.

Lubrication. Grease is standard. Special greases can be selected for low torque, high speed, low noise, or wide temperature ranges.

Applications

Thin section ball bearings work where space and weight are limited, and where motion must stay accurate.

• Industrial robot joints and robotic arms
• Automation and packaging machines
• Medical and laboratory devices
• Semiconductor and electronics equipment
• Optical, measuring and inspection instruments
• CNC and machine tool accessories
• Aerospace and defense mechanisms
• Rotary tables, turntables and positioning stages

Thin Section vs Standard Ball Bearings

Thin section bearings carry less load than a standard bearing of the same bore. If your load is heavy, consider a cross roller bearing instead. Cross roller bearings carry radial, axial, and moment loads in one compact unit.

How to Select a Thin Section Ball Bearing

Check these points before you order.

• Load. Measure radial load, axial load, and any moment load. Choose a contact type that fits.
• Space. Confirm the bore, outside diameter, and width your housing allows.
• Speed. Higher speed calls for the right cage, clearance and grease.
• Accuracy. Pick the running accuracy that your application needs.
• Environment. Consider dust, moisture, chemicals and temperature when you choose open, shielded or sealed.
• Mounting. Thin rings are flexible. Shaft and housing fits and roundness matter, so follow the recommended tolerances.
• Quantity. Tell us your volume. It affects price and lead time.

Custom and OEM Thin Section Bearings

LYDL Bearing is a precision bearing manufacturer based in Luoyang, China. We supply standard metric thin section ball bearings and can quote custom sizes, materials, closures, and lubrication for OEM projects.

To get a quote, send us your drawing or these details: bore, outside diameter, width, bearing type, closure, material, precision grade, lubricant, and annual quantity.

Frequently Asked Questions

What is a thin section ball bearing?

It is a ball bearing with a very small cross-section compared with its bore. It saves space and weight while keeping smooth, accurate rotation.

What is the difference between a thin section bearing and a standard bearing?

A standard bearing gets thicker as the bore gets larger. A thin section bearing keeps a slim profile at larger bore sizes. This makes it lighter and easier to fit in compact designs.

Which type handles axial load?

Four-point contact bearings handle axial load in both directions. Angular contact bearings handle it in one direction. Radial contact bearings take light axial loads in both directions.

Should I choose open or shielded bearings?

Choose open bearings for the lowest friction in clean conditions. Choose shielded or sealed bearings when dust or moisture is present.

Can thin section bearings carry heavy loads?

They suit light to medium loads. For heavy loads or moment loads, a cross roller bearing is often a better choice.

Do you make custom thin section bearings?

Yes. We can quote custom sizes, materials, closures, and lubricants for OEM and project orders.

How do I request a quote?

Send us your bearing number or drawing and your quantity. Our team will reply with pricing and lead time.

Request a quote for thin section ball bearings.