SKF SY 50 TF Pillow Block Ball Bearing Unit, 50 mm

A ready-to-mount pillow block unit for conveyors and material handling

The SKF SY 50 TF is a pillow block ball bearing unit: an insert bearing already fitted into a cast iron housing that bolts to a support surface. It suits a 50 mm shaft. The bearing has an inner ring extended on both sides, and is locked to the shaft with a set screw in the inner ring, so no sleeve or collar is needed. SKF notes that this variant suits applications with constant or alternating direction of rotation.

The product page lists the unit for material handling applications, in compliance with ISO dimensional standards. Typical uses are conveyors, fans and general light machinery, where a self-contained and relubricable bearing position is wanted at low cost. The unit arrives lubricated and sealed, ready to be bolted down.

Technical specifications

What is in the unit and how TF is defined

The SKF Y-bearing catalogue lists the SY 50 TF as housing SY 510 M with the Y-bearing YAR 210-2F, plus the end cover ECY 210 as an option, with a mass of 2.70 kg. YAR 2 bearings have an extended inner ring on both sides, which reduces how far the inner ring can tilt on the shaft so it runs more smoothly, and they are fitted with a standard integral seal and a plain sheet steel flinger, indicated by the suffix 2F in the bearing designation. The unit suffix TF refers to the YAR 2-2F series.

A sibling in the same size, the SY 50 TR, uses the rubberised flinger and has a limiting speed of 2 200 r/min instead of 4 000 r/min, and the SYJ 50 TF is a variant with a different housing. The unit has a dynamic rating of 35.1 kN, a static rating of 23.2 kN and a fatigue load limit of 0.98 kN, with a limiting speed of 4 000 r/min under the h6 shaft tolerance.

Installation notes

The set screw is M10x1 with a 5 mm hexagonal key, tightened to 16.5 N m according to the product page. Recommended attachment bolt diameter is 16 mm (0.625 in), and dowel pins of 4 mm can be used at a distance of 187 mm with an axial offset of 19 mm. Bolt hole centre distance is 157 mm, allowing 149 to 165 mm of adjustment, and overall length is 203 mm. The grease fitting thread is 1/4-28 UNF with a 1/4-28 SAE-LT fitting.

Ball bearing units accommodate moderate initial misalignment but do not normally permit axial displacement, so align the base carefully. Confirm the shaft tolerance (h6 recommended for the speed above), whether you need an end cover and the lubricant. Related bearing items are in Electric Motors and, for belt-driven shafts, the SKF TKBA 40 belt alignment tool.

Documents and quotation

The attached SKF catalogue, Y-bearings and Y-bearing units, describes the YAR 2 series, the seal and flinger options, the housing types and the product tables including the SY 50 TF row. The product page provides the dimensions in the table. Seven Star LLC, an independent supplier in Muscat, will quote on the designation and quantity you send.