SealMasterER-12TCSelf-Aligning Ball Bearing Insert ONLY, 3/4″ Bore, Spherical 1.85″ OD, Contact Seals, Regreasable, With Snap Ring — No Housing

Product Description

What this part is

A Sealmaster ER-12TC: a self-aligning ball bearing insert with a 3/4 in bore, a spherical outside diameter, contact seals and a grease fitting, supplied with its snap ring.

An insert is a bearing element rather than a bolt-on unit. Its spherical outer surface seats inside a matching spherical bore in a separate Sealmaster housing — a pillow block, a flange bracket, a take-up frame or a hanger.

What that architecture buys is the reason Sealmaster built it. When a bearing fails on a machine, the housing has almost always survived: cast iron does not wear out, and it is the balls, the raceways and the seals that give up. Replacing the insert alone leaves the housing bolted in place and the alignment undisturbed. On a machine with several identical stations that is a substantial saving in both parts and labour, and it is why plants that standardise on Sealmaster keep inserts on the shelf rather than complete units.

Decoding the order code

ER: Sealmaster’s self-aligning ball bearing insert series with a spherical (not cylindrical) outside diameter, medium duty, for ER-bore housings.

12: bore in sixteenths of an inch. 12/16 in = 3/4 in. The convention runs through the whole range, so the ER-12 insert and the FB-12 or SFT-12 housing share a bore.

TC: the seal and locking specification. Sealmaster’s own product copy for sibling units specifies the base parts with felt seals and a setscrew collar, and the TC-suffixed parts with contact seals and a Skwezloc collar. On that basis TC denotes the contact-seal build.

Why the spherical outside diameter matters

This is the specification that decides whether the insert will physically seat in a given housing.

The ER series has a spherical outside diameter — a section of a sphere, not a cylinder. It seats in a matching spherical housing bore, and the two surfaces together let the bearing swivel a few degrees relative to the housing. That swivel is the self-alignment: it takes up static angular error between two bearing stations, so the unit tolerates a fabricated frame, a hand-drilled mounting or a mounting face that is not quite true. Sealmaster publishes roughly ±2° on the housed families these go into, which over a 30 in shaft span is more than an inch of offset between bearing centres.

A spherical-OD insert pairs with a spherical-bore housing. In a cylindrical-bore housing built for a straight-OD cartridge the outer ring is loaded on two narrow bands rather than across its face, and a cylindrical insert in a spherical housing gives up the self-alignment the machine was designed around. Housing bore form is therefore the governing compatibility check.

Contact seals, regreasability and the snap ring

Contact seals rub on the inner ring, so they genuinely exclude dust, water and washdown spray rather than merely deflecting it — a step up from the felt seals on the base ER-12. Felt suits a clean dry plant.

Combined with the grease fitting, that gives the arrangement that survives dirty duty: a positive barrier keeping contamination out, plus the ability to purge fresh grease through and eject whatever gets past. A sealed-for-life bearing in the same position has no way to expel contamination once it is inside.

The snap ring is supplied and it is functional rather than packaging. It locates the insert axially in the housing bore, fixing which way the assembly is held. Some Sealmaster housings retain the insert by other means, so the housing design determines whether it is used.

Published data

Bore: 3/4 in (0.750 in).

Outside diameter: 1.85 in / 47 mm, spherical.

Width: 1.2190 in.

Duty rating: medium duty.

Bearing type: self-aligning ball bearing insert.

Seals: contact seals.

Locking: set screw / collar arrangement.

Lubrication: regreasable, grease fitting provided.

Snap ring: included.

Quantity and configuration

Sold as one insert complete with its snap ring. The matching housing is a separate Sealmaster part — for this bore the three-bolt flange bracket is the FB-12TC, which Central Surplus stocks as its own line.

Interchange guidance

Search forms include ER-12TC, ER12TC, ER-12-TC, ER 12 TC, ER-12, ER12, ER-12T. Sealmaster housings that accept a 3/4 in ER insert: FB-12TC (three-bolt flange bracket), SFT-12TC (two-bolt flange), SF-12TC (four-bolt square flange), NP-12TC and SP-12TC (pillow blocks), plus take-up and hanger frames in the same bore. Same-bore spherical-OD inserts are catalogued by Dodge (SC and INS families), Browning (VS and SLS), Link-Belt (now Regal Rexnord) and Timken; outside diameter, spherical geometry and snap-ring retention govern whether any of them is a drop-in, because insert ODs and retention methods are not standardised across brands. Sealmaster and Link-Belt both now sit under Regal Rexnord, so units originally specified under either name are supported today.