SealMasterFB103-Bolt Flange Bracket Ball Bearing Unit 5/8″ Bore, Setscrew Locking, Felt Labyrinth Seal, Non-Expansion

Product Description

What this part is

A SealMaster FB-10 mounted ball bearing unit — a three-bolt flange bracket in cast iron for a 5/8 inch shaft. The bracket form offsets the shaft from the mounting face, so the housing carries a base-to-shaft-centre dimension the way a pillow block does. The insert is a setscrew-locking ball bearing with a felt labyrinth seal and flinger, seated so the unit accommodates static misalignment of about ±2°.

Decoding the designation

FB = three-bolt flange bracket, setscrew locking. 10 = 5/8 inch bore in SealMaster’s size code; the shaft size code for this unit is 2-012 and the insert inside it is a 2-010. 701231 is the SealMaster part number, and this is a Gold Line standard-duty build.

Housing style and bolt pattern

Three-bolt flange bracket. Bolt spacing is 1-1/2 in, bolt spacing in the height direction is 7/8 in, bolt size is 3/8 in, and the base-to-shaft-centre height is 3 in. In this same 5/8 in bore, SealMaster’s two-bolt flange units are SFT-10 and FT-10, and its four-bolt flange is the SF series — each has its own bolt pattern and mounting footprint.

Published ratings and mounting data

Housing style: three-bolt flange bracket, cast iron, one piece, powder coated blackBore / shaft size: 5/8 in (0.625 in), straight boreBase to shaft centre height: 3 inBearing centreline to bolt hole centre: 1-11/16 inBolt spacing: 1-1/2 in · bolt spacing, height direction: 7/8 inBolt size: 3/8 inOverall length: 4-3/16 in · overall width 2-3/8 in · overall height 1.34 inHousing width: 2.38 in · foot height 0.31 inLocking method: set screwsExpansion type: fixed (non-expansion)Seal type: felt labyrinth seal, with flingerInsert: 2-010, 52100 bearing steel, black oxide, zone-hardened inner raceInsert inner ring OD: 1.192 in · length through bore 1.219 inRetainer: land-riding, polyphenylene sulfideDynamic load capacity: 2,611 lbStatic load rating: 1,444 lbMaximum speed: 7,300 rpmMaximum operating temperature: 220 °FMisalignment capability: −2° to +2°, static onlyLubricant: lithium complex NLGI 2 grease · grease fitting 1/4-28Relubricatable: yesHTS 8483.20.4040

What these specs mean in practice

The ±2° misalignment figure is static. The insert is aligned once at installation and holds that position in service, so this unit suits a shaft that stays where it is put rather than one that deflects under load.

The felt labyrinth seal and flinger make a dry-duty arrangement. It sheds airborne dust well and runs with very low drag, which is where the 7,300 rpm ceiling comes from. Wet or washdown duty calls for a contact-sealed variant such as the FB-10TC single lip contact seal.

Non-expansion means this position locates the shaft and carries thrust. On a two-bearing shaft the opposite end takes an expansion unit or a free seat, which lets the shaft grow thermally without loading either bearing.

Quantity and configuration

Sold as 1 pc — one complete unit, cast iron bracket with insert and setscrews fitted. Mounting bolts and end cap are not included.

Fitting notes

A bracket housing is more sensitive to a twisted mounting face than a flat flange is, so it goes onto a flat rigid face, shimmed where the surface is uneven. Slide the unit onto the shaft, set the position, then torque both setscrews evenly. Rotate the shaft by hand and purge the grease path through the 1/4-28 fitting with a compatible lithium complex NLGI 2 grease before running.

Interchange guidance

Three-bolt flange bracket units in this style also come from Link-Belt as the FB3 series and from Rexnord as the MFB flanged bracket unit. Bolt spacing and base-to-shaft-centre height vary between makers, so this unit’s 1-1/2 in bolt spacing and 3 in centre height are the dimensions to match. Related sizes rather than interchanges: SealMaster NP-10 carries the same 2-010 insert in a two-bolt pillow block, and SFT-10 and FT-10 are the two-bolt flange units in this bore.