Timken Corrosion-Resistant Mounted Ball Bearings Stainless and Polymer Housings

Stainless steel and polymer mounted ball bearings for food and washdown service

Timken corrosion-resistant mounted ball bearings are built for machines that are hosed down with hot water and chemicals: conveyors, mixers, metal detectors, check-weighers, tumblers, slicers, breaders, peelers and bottling lines. The ball bearing insert is made entirely of stainless steel, with a set screw lock, a metal cage and a double-lip seal for higher ingress protection, and it sits in either a stainless steel housing or a polymer (thermoplastic) housing. Because the whole bearing is metal, it can be picked up by metal detectors.

The hygienic housings have a smooth surface, solid base, rounded shape and laser marking with co-moulded bushings, and are certified as accepted equipment by the USDA under its Meat and Poultry Equipment Review Program. Timken states that the designs follow NSF/ANSI/3-A SSI 14159-1 requirements and use FDA-compliant NSF H1 food-grade lubricants. Optional blue thermoset housings make fragments visible.

Technical specifications

Sample units with stainless inserts in polymer pillow blocks, from the Timken corrosion-resistant housed unit catalogue (standard-duty 200 series):

Reading the code and choosing grease or Solid Lube

A code such as SUC205-16/F reads: S stainless insert, UC set screw locking, 2 standard duty, 05 the bore code and -16 a one inch bore (sixteenths), with /F for food-grade grease. The housing prefix identifies the material (S stainless steel, PL thermoplastic, A hygienic stainless, B blue thermoset) and the type (P pillow block, FL two-bolt flange, FB three-bolt, F four-bolt, T wide-slot take-up, TB tapped base). For metric bores, the code from 04 upward times five gives the bore in millimetres.

Grease-filled units can be relubricated. Where washdown makes relubrication impractical, food-grade Solid Lube (FVSL613, an NSF H1 polymer) fills the free space in the bearing, so no grease purges and no regreasing is needed. Timken also offers industrial-grade Solid Lube VSL609 for non-food applications.

What to confirm before ordering

Confirm the shaft size, housing material and style, whether metal detection or optical detection is needed, grease or Solid Lube, the cleaning chemicals and temperature, and the mounting dimensions of the existing unit. Below minus 40 degrees Celsius polymer housings may break, so choose stainless or steel housings for colder service. See also Electric Motors, Pumps and Turbines.

Stainless or polymer housing: how to decide

Both housing families carry the same all-stainless insert, so the choice is mainly about the environment around the bearing and the hygiene rules of the plant.

Whichever housing is chosen, the mounting style (pillow block, two-, three- or four-bolt flange, take-up or tapped base) should match the existing frame so that shaft height and bolt pattern stay the same when replacing an older unit.

Installation practice for washdown lines

Set screw locking is simple, but it rewards care. Clean the shaft, check that it is within the tolerance recommended by Timken, slide the bearing on without hammering the insert, align the housing, tighten the base bolts and only then tighten both set screws to the recommended torque. Misalignment between two bearings on the same shaft adds load to the seals and shortens life far more than the washdown itself.

• Mount the unit so that water can drain from the housing and the frame rather than pooling around the seal.
• Point high-pressure spray at the surfaces to be cleaned, not directly into the seal lip.
• Where the relubricable option is used, purge with the specified food-grade grease after washdown so that water is pushed out of the bearing.
• Solid Lube fills the free space in the bearing, which limits room for water and contamination and removes the need for regular regreasing.

Inspection during sanitation shutdowns

Listen for roughness when turning the shaft by hand, look for grease weeping or discoloured product near the bearing and check set screws for loosening. Replacing a bearing during a planned stop is far cheaper than losing a shift of production or a batch of product.

Food, beverage and dairy plants in Oman and the GCC

Poultry, meat, dairy, bakery, bottled water and juice plants across the region run daily caustic and acid washdowns, often with hot water, while ambient humidity in coastal areas such as Muscat, Sohar and Salalah is high. Standard grey-iron mounted bearings rust quickly in these conditions and need frequent replacement. A stainless or polymer unit with food-grade lubricant removes the rust source and supports the hygiene audits that exporters and large retail customers expect.

RFQ checklist

• Full Timken part number, or the bore size (metric or inch) and housing style.
• Housing material: stainless steel, standard polymer or blue detectable.
• Lubrication: food-grade grease, relubricable, or Solid Lube.
• Shaft speed, approximate load and operating temperature.
• Cleaning chemicals and water temperature used at the plant.
• Quantity, including spares for planned shutdowns.

Documents and quotation

The attached Timken sell sheets describe the construction, nomenclature and product range; the full corrosion-resistant housed unit catalogue is available from Timken. Send the exact unit code and quantity when requesting a quotation from Seven Star LLC, an independent supplier in Muscat.