6909 LU 45x68x14mm Thin Wall Deep Groove Ball Bearing – Lightweight Automotive & Precision Equipment Component

Product Overview

The 6909 LU is a high‑precision, thin‑section single‑row deep groove ball bearing with compact dimensions of 45x68x14mm. Its slim cross‑section design offers significant weight and space savings while maintaining excellent radial load capacity – making it the ideal choice for automotive applications where packaging efficiency is critical, such as alternators, starter motors, water pumps, and HVAC blowers.

Engineered with GCr15 chrome steel, dual rubber seals (2RS), and a robust steel cage, the 6909 LU delivers reliable, maintenance‑free operation in demanding under‑hood environments. The C3 radial internal clearance ensures stable performance across temperature fluctuations, while the contact seals provide effective protection against dust, moisture, and lubricant loss. As a non‑standard thin‑wall bearing, it offers design engineers a solution for constrained spaces without compromising on durability or rotational accuracy.

Technical Specifications

Design & Construction Features

Thin‑Wall / Thin‑Section Design – With a slim cross‑section and reduced overall width compared to standard series bearings, the 6909 LU enables more compact and lightweight component designs. This is particularly beneficial in automotive and aerospace applications where every millimetre and gram counts.

Deep Groove Raceway Geometry – Optimised for high radial load capacity and low running torque, the deep groove design also supports moderate axial loads in both directions, making it suitable for shaft and housing arrangements with combined load requirements.

GCr15 Chrome Steel – Manufactured from vacuum‑degassed, high‑carbon chromium bearing steel, the 6909 LU offers superior hardness (HRC 60‑65), excellent wear resistance, and outstanding rolling contact fatigue strength, ensuring long service life under continuous high‑speed operation.

2RS Rubber Seals – Integrated contact seals on both sides provide an effective barrier against dust, dirt, moisture, and other contaminants, while retaining the pre‑filled grease. The NBR seals are formulated to withstand under‑hood temperatures (-40°C to +120°C) and resist degradation from engine oils and coolants.

Robust Steel Cage – The stamped steel cage offers high strength, heat resistance, and dimensional stability, making it suitable for applications with higher operating temperatures and speeds where nylon cages may be less durable.

C3 Radial Internal Clearance – The C3 clearance ensures stable operation under thermal expansion and interference fits, preventing excessive preload and heat buildup during extended running periods.

Materials & Quality Assurance

All 6909 LU bearings undergo 100% quality inspection, including dimensional accuracy, radial runout, noise and vibration testing (V3/V4 standards available), seal integrity checks, and torque measurement, in compliance with ISO 9001 and IATF 16949 quality management systems.

Applications

The 6909 LU is specifically designed for space‑constrained automotive and industrial applications where thin‑section bearings are required:

• Automotive Alternators – Supports the rotor shaft in compact, high‑speed generator assemblies

• Starter Motors – Provides reliable support under high starting torque and vibration

• Electric Water Pumps – Ensures quiet, long‑life operation in engine cooling circuits

• HVAC Blower Motors – Allows compact fan motor designs with smooth, low‑noise rotation

• Engine Cooling Fans – Withstands thermal cycling and belt‑drive loads

• Industrial Electric Motors – Space‑saving shaft support in servo motors and small drive units

• Robotics & Precision Equipment – Thin‑section design suits limited envelope applications

• Power Tools & Medical Devices – Lightweight, compact bearing solutions for portable equipment

Customization & OEM Services

We offer comprehensive OEM and aftermarket support for the 6909 LU, including:

• Custom internal clearances (C2, C3, C4) and precision grades (P5, P6)

• Alternative seal materials (e.g., Viton, PTFE) for extreme chemical or temperature conditions

• Modified cage designs (nylon, machined brass) upon request

• Custom lubricants for low‑noise, high‑speed, or extended‑life requirements

• Private labelling, packaging, and branding

• Non‑standard bore, OD, or width modifications

Please consult our engineering team for tailored solutions to fit your specific design envelope.

Packaging, Shipping & Logistics

Ordering Information