The NSK UC204-12 Bearing Pillow Block Unit is a mounted bearing assembly designed to support rotating shafts in industrial equipment. It combines a precision UC204-12 insert ball bearing with a pillow block housing (often referenced as UCP204-12) for easy installation, reliable performance, and long service life in medium-duty applications.

Product Overview

A bearing pillow block (also called a plummer block) consists of a bearing insert mounted inside a rigid housing that can be bolted to a frame or support surface. The UC204-12 model features a set-screw locking insert which helps secure the bearing to a rotating shaft.

Core Components

• Bearing Insert: UC204-12 insert bearing with set screws for locking to shaft.

• Pillow Block Housing: Cast iron housing (commonly P204 or equivalent) that protects the bearing and provides mounting points.

Key Specifications

(Typical for UC204-12 pillow block units — actual values may vary slightly by manufacturer)

• Insert Bearing Model: UC204-12

• Bore (Shaft Diameter): 3/4″ (19.05 mm)

• Outer Diameter of Bearing: ~47 mm

• Bearing Width: ~17 mm

• Housing Type: 2-bolt Pillow Block (cast iron)

• Housing Length: ~5.0″ (127 mm)

• Center Height: ~1-5/16″ (33 mm)

• Bolt Hole Distance: ~3-3/4″ (95 mm)

• Weight: ~0.7 kg

• Locking Device: Set screws on insert inner ring

• Housing Material: Cast iron

• Bearing Material: Chrome steel (GCr15)

Features & Benefits

✔ Complete Pillow Block Assembly – Bearing insert paired with housing for quick, secure mounting.
✔ Set Screw Shaft Locking – Insert bearing locks to shaft easily using set screws.
✔ Self-Aligning Support – Ball bearing insert accommodates slight shaft misalignment.
✔ Durable Construction – Cast iron housing and chrome-steel insert for use in industrial environments.
✔ Easy Installation & Replacement – Housing mounts with two bolts; insert can be replaced separately if needed.
✔ Moderate Load & Speed Support – Suitable for conveyors, rollers, fans, and general shaft support where moderate loads are present.

Typical Applications

The UC204-12 pillow block bearing unit is widely used in industrial and mechanical systems such as:

• Conveyor rollers & belt systems

• Material handling equipment

• Agricultural machinery shafts

• Fans, blowers & HVAC equipment

• Pumps, compressors & mixers

• General rotating shafts with moderate radial loads

How It Works

The insert bearing (UC204-12) supports the rotating shaft, while the housing (P204) provides a secure mounting platform. Set screws on the insert's inner ring clamp the bearing to the shaft so it stays fixed during rotation. The pillow block unit can be bolted to machine frames, mounts, or substructures to support horizontal shafts in position.

Installation Notes

• Ensure the shaft diameter matches the 3/4″ bore before installation.

• Tighten set screws evenly to avoid shaft damage.

• Use grease fitting (if present) for periodic relubrication to extend bearing life.

• Mount housing using correct bolt size for stable performance.