Bearing units
Published by NHK Group ApS
Bearing units sit on almost every rotating shaft in a food or pharmaceutical machine: conveyors, mixers, slicers, packaging lines. In washdown areas they are also one of the most common sources of unplanned stops. Water and detergent get past the seals, wash out the grease, and the bearing fails early.
Choosing the right housed unit is therefore both a hygiene decision and a maintenance decision. Housing material, seal design, the shape of the outer surfaces and the lubrication concept all decide how well a unit survives daily cleaning and how easily it can be cleaned itself.
This section compares the main options: stainless steel housings, thermoplastic and composite housings, sealed and relubricable designs, and units with IP54 or IP67 protection. It also covers mounting, end covers, mini bearing units for compact machines, and how to read the ratings manufacturers publish.
The aim is practical: to help you match a bearing unit to its position in the machine, the cleaning regime it will see, and the service interval you can accept.
Bearing unit types
Pillow block, flange (2/3/4-bolt), mini and plummer units, waterproof IP67/IP69K and thermoplastic units, covers.
Bearing Units: Types of Bearing Block and How to Choose for Hygienic Areas
Bearing units compared: pillow block, tapped base, 2/3/4-bolt flange, cartridge and take-up types, housing materials, sealing and a selection method.
Stainless Steel Pillow Block Bearings for Washdown: Selection Guide
Stainless steel and waterproof pillow block bearings for washdown: 304 vs 316 housings, 440C inserts, seals, food-grade grease, sizing and an RFQ checklist.
Bearing Cover Guide: Open vs Closed End Covers for Bearing Units
Bearing cover guide: open vs closed end covers, stainless vs plastic bearing covers, hygiene and safety, selection steps, fitting and inspection checklist.
Bearing Unit Designations: Decode F208, PPL and Housing Codes
Decode UCP, UCF, FL206, PPL and stainless housing series. Separate insert and bore codes, then check drawings for a hygienic replacement.
Flange Bearing Guide: Types, Housings, Sealing and Mounting
How to choose a flange bearing: 2-bolt oval vs 4-bolt square vs 3-bolt, housing materials, seals for washdown, a load example and a mounting checklist.
Mini Bearing Units in Stainless Steel: Selection for Light Conveyors and Packaging
Mini bearing units in stainless steel: where they fit, pillow block vs flange, sizing with ISO 281, sealing for washdown, failure modes and RFQ checklist.
Pillow Block Bearings: The Complete Guide for Industrial and Hygienic Applications
Pillow block bearing guide: insert and housing types, pillow block vs flange vs plummer block, hygienic design, life calculation, installation.
Square Ball Bearing Unit in IP54 Composite Housing: Where It Fits and Where It Doesn't
What a square 4-bolt flange ball bearing unit in IP54 thermoplastic housing offers, what IP54 means, where to use it, how to select and install it.
Plastic Bearing Units: Bearing Units in Waterproof Composite Housing
When plastic bearing units beat metal: composite housing materials, IP ratings, load and temperature limits, selection steps and an installation checklist.
Industrial Oval Bearings: Where and Why to Use Oval 2-Bolt Flange Units
What industrial oval bearings really are – oval 2-bolt flange units – how they compare with square flanges and pillow blocks, and how to select and fit them.
Waterproof Bearings: Sealed Waterproof Stainless Steel Bearing Units Explained
How waterproof bearings work: stainless grades, seal types, grease and load trade-offs, with a selection method and checklist for sealed stainless units.
Waterproof Bearing House Units: Where and Why to Use a Sealed Bearing House
What a waterproof bearing house does, where it is needed, how IP67 and IP69K differ, and how to select, install and inspect bearing house units.
Mounted Ball Bearing Units in Stainless Steel: Selection and Sizing
How to choose mounted ball bearing units in stainless steel: housing types, insert locking, life calculation with stainless ratings, and installation.
Sealed Stainless Bearing Units: Hygienic Bearing Units by Industry
What makes sealed stainless bearing units hygienic: 304 housings, 440C inserts, covers and grease, plus selection by industry and a buyer checklist.
IP67 Waterproof 4-Hole Square Flange Bearing Units: Selection Guide
When to use a 4-hole square flange bearing, what IP67 does and does not mean for washdown, and how to select, mount and inspect waterproof flange units.
Waterproof Bearing Units Designed for Easy Cleaning: Design and Cleaning Routine
What makes waterproof bearing units easy to clean, and how to clean them without forcing water past the seals: design checks, routine and failure modes.
IP67 Waterproof Oval Bearing 2-Hole Flange Units: Pillow Type Unit with Rhombic Flange
Oval, rhombic or 2-bolt flange? What the names mean, when an IP67 waterproof oval flange bearing fits, how to replace one and what IP67 really covers.
Bearing loads, fits and maintenance
Failure causes after washdown, static vs dynamic load ratings, shaft tolerances, NSF H1 relubrication, fretting and maintenance strategy.
Bearing Failure Causes: Washdown Diagnosis and Prevention
Diagnose water ingress, corrosion, lubricant loss, misalignment, overload and fretting. Read bearing damage and specify seals, units and relubrication.
Fretting Corrosion in Bearing Units: Diagnosis and Prevention
What is fretting corrosion? Identify bearing-seat damage, separate false brinelling and rust, then check fits, locking and vibration before repairs.
NSF H1 Lubricant: Bearing Grease and Relubrication
Understand H1 incidental-contact registration, compare lifetime and relubricable bearings, and check washdown servicing without over-greasing.
Shaft Tolerance for Insert Bearings: Choose and Check the Fit
Choose and check insert-bearing shaft fits: locking methods, h7 versus h9, measurement, wrong-fit symptoms and the evidence to send NHK.
Static vs Dynamic Load Rating: C, C0 and L10 Life
Compare bearing C and C0 ratings, calculate basic L10 life with a worked example, and check shock loads, washdown, housing and lubrication limits.
Preventive vs Predictive Maintenance in Washdown Areas
Compare scheduled inspections and condition monitoring for washdown bearings, feet and castors. Build a maintenance plan and document when to intervene.
Need components for this application?
NHK Group supplies hygienic bearing units, levelling feet, castors and conveyor components for food, dairy, beverage and pharmaceutical machinery.