UCTB200 Series Tapped Base Pillow Block Bearing Units — Inch UNC Tapped Base
The UCTB200 series is built specifically for machine frames that use inch UNC thread standards throughout. The G column in the specification table lists the UNC thread designation (3/8-16UNC, 7/16-14UNC, 1/2-13UNC, 5/8-11UNC) rather than a metric M designation. This makes UCTB200 the natural choice for North American and British Commonwealth equipment, agricultural machinery manufactured to ASABE standards, and any machine where the frame was designed to inch bolt conventions and sourcing metric-thread pillow blocks would require non-standard thread adapters.
Inch UNC Threading — Why It Matters for Frame Integration
In a machine frame built to inch UNC standards, using a metric tapped-base bearing housing creates a thread mismatch that requires an adapter bushing or a compromise thread pitch. On equipment maintained in the field with inch-standard tooling — common on North American farms and general industrial machinery — a metric thread in a bearing housing base creates a parts and tooling incompatibility that reduces maintenance efficiency. UCTB200 eliminates this by providing UNC threads that match the same bolts used throughout the rest of the machine frame.
The J dimension (bolt circle) at UCTB201–205 is 50.8 mm — exactly 2 inches. UCTB206 steps to J = 76.2 mm (exactly 3 inches), and UCTB207 onward to 82.6 mm (3-1/4 inches), maintaining alignment with inch-standard structural sections throughout the range.
Key Features
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Inch UNC Threads as Standard
G column specifies UNC thread: 3/8-16UNC (12–25 mm), 7/16-14UNC (30 mm), 1/2-13UNC (35–45 mm), 5/8-11UNC (50–55 mm). No adapter required in inch-standard frames.
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2-Inch and 3-Inch Bolt Grid Alignment
J = 50.8 mm (2.000 in) for UCTB201–205 and J = 76.2 mm (3.000 in) for UCTB206. Direct match for standard structural steel section bolt patterns.
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Dual Setscrew Locking at 120°
Same retention geometry as UCP200. Bidirectional and intermittent-duty capable. Maintenance procedure identical to UCP200.
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Wide Inner Ring UC Insert
Self-aligning spherical OD UC insert. Wide inner ring accommodates axial float. Up to 2° angular misalignment compensation.
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Compact Base Design
Housing base profile shorter and more compact than equivalent UCPA200 in most bore sizes.
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ASABE / ANSI / BS Compatible
Housing dimensions align with ASABE, ANSI, and BS standards for pillow block bearing units in agricultural and industrial equipment.
Full Dimensional Specifications
| Unit No. | d mm | d inch | H mm | L mm | J mm | A mm | H1 mm | H0 mm | G (UNC) | S mm | B mm | kg |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UCTB201 / 201-8 | 12 | 1/2 | 33.3 | 73 | 50.8 | 38 | 10.9 | 65 | 3/8-16UNC | 12.7 | 31 | 0.77 |
| UCTB202 / 202-9/10 | 15 | 9/16~5/8 | 33.3 | 73 | 50.8 | 38 | 10.9 | 65 | 3/8-16UNC | 12.7 | 31 | 0.75 |
| UCTB203 / 203-11 | 17 | 11/16 | 33.3 | 73 | 50.8 | 38 | 10.9 | 65 | 3/8-16UNC | 12.7 | 31 | 0.74 |
| UCTB204 / 204-12 | 20 | 3/4 | 33.3 | 73 | 50.8 | 38 | 10.9 | 65 | 3/8-16UNC | 12.7 | 31 | 0.73 |
| UCTB205 / 205-14~16 | 25 | 7/8~1 | 36.5 | 76 | 50.8 | 38 | 12 | 71 | 3/8-16UNC | 14.3 | 34.1 | 0.83 |
| UCTB206 / 206-17~20 | 30 | 1-1/16~1-1/4 | 42.9 | 102 | 76.2 | 38 | 12 | 86 | 7/16-14UNC | 15.9 | 38.1 | 1.36 |
| UCTB207 / 207-20~23 | 35 | 1-1/4~1-7/16 | 47.6 | 108 | 82.6 | 48 | 13 | 95 | 1/2-13UNC | 17.5 | 42.9 | 1.83 |
| UCTB208 / 208-24/25 | 40 | 1-1/2~1-9/16 | 49.2 | 117 | 88.9 | 48 | 13 | 100 | 1/2-13UNC | 19 | 49.2 | 2.13 |
| UCTB209 / 209-26~28 | 45 | 1-5/8~1-3/4 | 54 | 127 | 95.3 | 51 | 14 | 108 | 1/2-13UNC | 19 | 49.2 | 2.75 |
| UCTB210 / 210-30~32 | 50 | 1-7/8~2 | 57.2 | 140 | 101.6 | 51 | 14 | 117 | 5/8-11UNC | 19 | 51.6 | 3.08 |
| UCTB211 / 211-32~35 | 55 | 2~2-3/16 | 57.2 | 140 | 101.6 | 51 | 14 | 117.5 | 5/8-11UNC | 22.2 | 55.6 | 3.37 |
→ Scroll table horizontally to view all columns. Catalogue dimensions for reference only — engineering drawings required before order.
G = UNC tapped thread in housing base. J = bolt hole centre spacing (50.8 mm = 2.000 in for UCTB201–205; 76.2 mm = 3.000 in for UCTB206). Bolt length must provide minimum 1.5 × diameter thread engagement into housing.
Applications
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North American Agricultural Equipment
Combine harvester auxiliary shafts, grain cart drive shafts, and field equipment where ASABE-standard inch bolt conventions are used throughout and field maintenance with inch-standard tooling is the norm.
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Structural Steel Frame Builds to Inch Standards
Equipment frames built on standard inch-dimension structural channels, angles, and plates where 2-inch or 3-inch bolt grids are specified and all tapped holes use UNC threads.
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British Commonwealth Industrial Machinery
Process machinery and materials handling equipment in markets where BS inch standards remain common in legacy and ongoing equipment designs.
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Construction Equipment Auxiliary Drives
Concrete mixer drum drive shafts and compactor vibration mechanism shafts built to North American inch standards.
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Inch-Standard Packaging Machine Frames
Tabletop and stand-alone packaging machines manufactured to North American dimension standards where the frame uses UNC fasteners throughout.
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Replacement in Imperial-Frame Machines
Direct replacement for worn tapped-base bearings in any existing machine frame using UNC threads and 2-inch or 3-inch bolt grid spacing.
📦 MOQ & Order Information
- Standard parts: quantity-based MOQ applies per model number.
- High-value / large items: minimum order by USD order value.
- New-client samples: 1–5 pcs available at sample price for first-time buyers.
- Multi-model combines: aggregate orders of USD 1,500 or more across models accepted.
- Special materials / processes: subject to process MOQ — confirm at inquiry stage.
- Retail (1–2 pcs): not accepted. Minimum sample order is 1–5 pcs at sample pricing.
Detailed engineering drawings must be submitted and approved before order confirmation. Catalogue dimensions are for reference only.
Comparing UCTB200 with Other Tapped Base Series
UCTB200 is the definitive choice when the machine frame uses UNC threads as standard and J dimensions align with 2-inch or 3-inch structural grids. If the frame uses metric threads but the tapped base configuration is still required, UCPA200 (centred holes) or UCPW200 (W-type bilateral) are the appropriate metric alternatives. If above-housing access is available and positional adjustment before lock-down is needed, the standard clearance-hole UCP200 provides this flexibility.
Frequently Asked Questions
What UNC threads are used?
3/8-16UNC (12–25 mm), 7/16-14UNC (30 mm), 1/2-13UNC (35–45 mm), 5/8-11UNC (50–55 mm).
Why J = 50.8 mm?
50.8 mm = exactly 2 inches — matches standard structural steel section bolt grids in inch-dimension frame designs.
Can it accept both metric and inch bore inserts?
Yes. Base thread and bore are independent selections — specify both when ordering.
What is the MOQ?
Standard parts: quantity-based MOQ. Samples 1–5 pcs. Multi-model from USD 1,500. Retail 1–2 pcs not accepted.
Request a Quote for UCTB200 Series
Provide shaft diameter, bore type (metric or inch), and confirm UNC thread standard is required. Contact us.
