Product Introduction

The 61900 Series Deep Groove Ball Bearings belongs to the "19" dimension series (Width Series 1 + Diameter Series 9) and bears model numbers starting with "619" (e.g., 61904, 61905, 61906). The 61900 series shares identical dimensions with the 6900 series, making them interchangeable.

Positioned as a versatile option within the thin-section bearing category, the 61900 series single-row Deep Groove Ball Bearing strikes a balance: it is more robust, offers higher load capacity, and provides greater rigidity than the 61800 series, yet is lighter, thinner, and has a smaller outer diameter than the standard 6000 series. It serves as a "bridge" between thin-section and standard series, offering the greatest versatility among thin-section bearings.

Single row deep groove Ball Bearings represent the most common type of rolling bearing and are widely used. They primarily consist of an inner ring, an outer ring, steel balls (rolling elements), and a cage. In addition to open designs, these bearings are available with steel shields (ZZ type), rubber seals (2RS type), or a snap ring groove on the outer ring (NR type). Pressed steel cages are commonly used.

Characterized by low frictional torque, these bearings are ideal for applications requiring high speeds, low noise, and low vibration. They primarily accommodate radial loads but can also handle moderate bidirectional axial loads. When radial internal clearance is increased, they exhibit properties similar to angular contact ball bearings, allowing them to withstand alternating axial loads in both directions.

Structure and Characteristics

The structure of the 61900 series is consistent with other single-row deep groove ball bearings. Its thin-section design offers the following characteristics:

Balanced Thin-Section Profile: While the outer diameter and width are on the larger end of the thin-section spectrum, they remain smaller than those of the standard 6000 series, resulting in a compact radial footprint.

Superior Load Capacity: Offering the highest load capacity within the thin-section category, this series features larger and more numerous steel balls, enabling it to support light-to-moderate loads. High Rigidity: The rings are thicker than those of the 61800 series, offering superior rigidity and deformation resistance, as well as relatively relaxed requirements for housing bore precision.

High Speed Capability: Limiting speeds are higher than the 6000 series but lower than the 61800 series, making them suitable for medium-to-high speed applications.

Wide Selection: Specifications range from small to large sizes, with a rich variety of sealing options, precision grades, and cage types; it offers the broadest selection within the thin-section bearing family.

High Cost-Performance Ratio: It boasts the highest production volume and most mature manufacturing process among thin-section series, offering affordable pricing and excellent versatility.

Dual Naming Convention: The same size is designated as both the 61900 series and the 6900 series; buyers should pay attention to the manufacturer's specific naming conventions.

Dimensional Parameter Table

Note: The 61900 series and 6900 series share identical dimensions and are interchangeable.

Common Suffixes

Open: No seals; suitable for oil lubrication.

ZZ / 2Z: Double-sided metal shields; the most common sealing type; dust-proof but not waterproof; supports higher speeds.

2RS: Double-sided rubber seals; protects against dust, water, and grease leakage; maintenance-free; suitable for harsh environments.

C2: Internal clearance smaller than standard; for high-precision, low-vibration applications.

C3: Internal clearance larger than standard; for applications involving temperature rise.

/P5 / P4: The 61900 series is frequently used in precision equipment, offering a wide range of high-precision grade options.

M / TN9: Cage materials; M denotes brass, TN9 denotes reinforced nylon.

NR: Outer ring features a snap ring groove and snap ring for easy axial positioning.

Application Scenarios

The 61900 series thin-section bearings are highly versatile, boasting the widest range of applications within the thin-section category:

Motor Industry: Small servo motors, stepper motors, micro-motors, and encoder motors—characterized by compact space, moderate loads, and high speeds.

Home Appliances & Smart Home: Air conditioners, washing machines, vacuum cleaners, robot vacuums, smart locks, and projectors—characterized by limited space, mass production, and low-noise requirements. Automotive components: Wiper motors, seat motors, sunroof motors, blower motors, automotive electronics — limited installation space.

Office equipment: Printers, copiers, scanners, paper shredders — roller and gear support; light loads, medium speeds.

Precision instruments and medical equipment: Measuring instruments, analytical instruments, medical devices, dental handpieces — miniaturization, low noise, high precision.

Robotics and automation: Robot joints, harmonic drives, servo motors, conveyor rollers — compact space, medium loads, high precision.

Power tools: Electric drills, angle grinders, cutters, sanders — limited space, high speeds, subject to slight impact.

Textile and printing machinery: Textile spindles, printing press rollers, guide rollers — medium-to-high speeds, light loads.

Bicycles and sports equipment: Bicycle hubs, bottom brackets, pulleys, fitness equipment — requires lightweight design, medium loads.

Key Differences

The 61900 series (i.e., the 6900 series) acts as a "bridge" between thin-section series and standard series:

61800/6800 series (ultra-thin section): Thinnest and lightest, smallest outer diameter, lowest load capacity; used in precision applications with extremely limited space.

61900/6900 series (thin section): Thickest and most robust among thin-section series; offers the best load capacity and rigidity, the widest range of options, and the greatest versatility — **the top choice among thin-section series**.

16000 series (extra-light/narrow): Outer diameter matches the 6000 series, but the width is narrower; positioned between thin-section and standard series.

6000 series (extra-light): Falls into the standard series category; larger outer diameter and width than the 61900 series, higher load capacity, good versatility.

6200/6300/6400 series: Highest load capacity, largest dimensions, lowest speeds. 

Selection Recommendations

1.  Verify Naming Conventions: The 61900 and 6900 series share identical dimensions; confirm the manufacturer's naming convention when purchasing to avoid confusion.

2.  Prioritize the 61900 Series for Thin-Section Bearings: When space constraints require thin-section bearings, prioritize the 61900 series; it offers the highest load capacity, greatest rigidity, widest range of options, and best cost-performance ratio within the thin-section category.

3.  Check Space Constraints: If the outer diameter and width of the 61900 series fit the installation space, select it first; consider the 61800 series only if space is even more restricted.

4.  Verify Load Capacity: While the 61900 series has the highest load capacity among thin-section bearings, it remains lower than the 6000/6200 series; always calculate service life based on actual loads to ensure requirements are met.

5.  Check Rotational Speed: The 61900 series has a high limiting speed, but actual operating speed should ideally not exceed 80% of this limit. Note that the limiting speed for 2RS (sealed) versions is lower than for ZZ (shielded) versions.

6.  Select Sealing: Choose ZZ for dry environments (high speed), 2RS for humid, dusty, or outdoor environments (maintenance-free), and open bearings for oil lubrication or ultra-high-speed applications.

7.  Select Internal Clearance: Choose C0 for standard operating conditions at ambient temperature, C3 for applications involving temperature rise (such as electric motors), and C2 for precision, low-vibration applications.

8.  Consider the 6000 Series as an Alternative: If the installation space allows for a slightly larger outer diameter and width, the 6000 series is a safer, more reliable choice; it outperforms the 61900 series in load capacity and rigidity while offering a wider selection and more affordable pricing.