NAFS200 Series 4-Bolt Flange Bearing Units — Eccentric Collar, Extended Housing Height
The NAFS200 series addresses a specific dimensional problem that arises with eccentric collar flange units at larger bore sizes: the wide inner ring of the NA insert bearing extends beyond the face of a standard-height flange housing, creating an exposed inner ring section that can catch on adjacent components, be damaged during installation, or cause clearance issues with guards and covers. The NAFS200 housing uses a taller overall profile (higher A dimension than NAF200 at equivalent bore sizes) that fully encloses the extended inner ring within the housing profile, eliminating the protrusion. This makes the NAFS200 the correct selection when both eccentric collar locking and full housing coverage of the wide inner ring are required in a four-bolt flange unit.
Extended Housing Height — Why NAF200 Is Not Always Sufficient
The NA insert bearing used in NAF200 and NAFS200 has a wider inner ring than the UC insert in UCF200. At larger bore sizes, this wider inner ring extends axially beyond what the standard NAF200 flange housing height can contain. In applications where the flange is mounted on a panel and the shaft end or an adjacent coupling runs close to the flange face, the protruding inner ring creates a risk of contact or a clearance violation. NAFS200 resolves this by using the same eccentric collar insert but a taller housing that keeps the inner ring within the housing body at all bore sizes from NAFS201 to NAFS216.
Key Features
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Extended Housing Height
Higher A dimension than NAF200 at equivalent bore sizes fully encloses the wide inner ring. No inner ring protrusion beyond the flange face.
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Eccentric Collar Self-Tightening
Same NA series eccentric collar insert as NAF200. Collar tightens under unidirectional shaft rotation — more secure than setscrew under sustained vibration and belt load.
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Same Four-Bolt Flange Plate
Four-corner bolt pattern. J and bolt size match NAF200 for equivalent bore sizes. Same mounting bolt positions.
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NAFS201S–203S Compact Variant
Slim S-series for 12–17 mm bore in applications where the reduced housing height is acceptable and the inner ring protrusion is not a concern.
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Metric and Inch Bore
12–80 mm metric bore with inch variants per housing size.
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GB / ISO / ANSI / JIS Compliant
Drop-in replacement for NAFS200-pattern flange units from all compliant manufacturers.
Full Dimensional Specifications
| Unit No. | d mm | d inch | L mm | J mm | A2 mm | A1 mm | A mm | N mm | B1 mm | S mm | Z mm | Bolt | kg |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NAFS201S~203S / 201-8S~203-11S | 12~17 | 1/2~11/16 | 76 | 54 | 15 | 11 | 24.5 | 11.5 | 37.3 | 13.9 | 38.4 | M10 | 0.66 |
| NAFS201~204 / 201-8~204-12 | 12~20 | 1/2~3/4 | 86 | 63.5 | 19 | 15 | 29.5 | 11.5 | 43.7 | 17 | 45.5 | M10 | 0.80 |
| NAFS205 / 205-11~16 | 25 | 11/16~1 | 93 | 70 | 19 | 15 | 30 | 11.5 | 44.4 | 17.4 | 45.9 | M10 | 0.95 |
| NAFS206 / 206-18~20 | 30 | 1-1/8~1-1/4 | 106 | 82.5 | 20 | 16 | 32.5 | 11.5 | 48.4 | 18.2 | 50.1 | M10 | 1.32 |
| NAFS207 / 207-20~23 | 35 | 1-1/4~1-7/16 | 116 | 92 | 21 | 17 | 35 | 14 | 51.1 | 18.8 | 53.3 | M12 | 1.77 |
| NAFS208 / 208-24/25 | 40 | 1-1/2~1-9/16 | 129 | 101.5 | 24 | 17 | 39 | 14 | 56.3 | 21.4 | 58.9 | M12 | 2.22 |
| NAFS209 / 209-26~28 | 45 | 1-5/8~1-3/4 | 135 | 105 | 24 | 18 | 40 | 16 | 56.3 | 21.4 | 58.9 | M14 | 2.63 |
| NAFS210 / 210-30~32 | 50 | 1-7/8~2 | 143 | 111 | 28 | 20 | 45 | 18 | 62.7 | 24.6 | 66.1 | M16 | 2.95 |
| NAFS211 / 211-32~35 | 55 | 2~2-3/16 | 162 | 130 | 31 | 21 | 49 | 18 | 71.4 | 27.7 | 74.6 | M16 | 4.10 |
| NAFS212 / 212-36~39 | 60 | 2-1/4~2-7/16 | 175 | 143 | 34 | 22 | 53.5 | 18 | 77.8 | 30.9 | 80.8 | M16 | 4.86 |
| NAFS213 / 213-40 | 65 | 2-1/2 | 184 | 149 | 38 | 22 | 58 | 18 | 85.7 | 34.1 | 89.6 | M16 | 5.90 |
| NAFS214 / 214-44 | 70 | 2-3/4 | 188 | 152 | 38 | 23 | 60 | 18 | 85.7 | 34.1 | 89.6 | M16 | 6.45 |
| NAFS215 / 215-47/48 | 75 | 2-15/16~3 | 200 | 159 | 41 | 24 | 62 | 18 | 92.1 | 37.3 | 95.8 | M16 | 7.55 |
| NAFS216 | 80 | — | 207 | 165 | 42 | 25 | 63 | 22 | 95.2 | 37.3 | 99.9 | M20 | 8.65 |
→ Scroll horizontally to view all columns. Catalogue dimensions for reference only — engineering drawings required before order.
B1 = eccentric collar insert width. S-suffix = compact variant with reduced housing height. Solid base: suffix SB. Eccentric collar lock direction must match shaft rotation direction.
Applications
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Coupling-Adjacent Flange Positions
Bearing positions immediately adjacent to shaft couplings or pulleys where the coupling flange or pulley hub runs close to the bearing housing face and the protruding inner ring of a standard NAF200 would cause interference.
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Guarded Drive Flange Supports
Belt and chain drive shaft flange supports inside safety guards where the guard profile is designed to clear the housing body and a protruding inner ring would require guard modification.
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Enclosed Agricultural Implement Frames
Shaft supports inside fully enclosed implement frame panels where the wide inner ring must be contained within the housing profile to fit between the panel face and adjacent internal components.
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Process Machinery Sealed Enclosures
Shaft supports on sealed process equipment where any protruding component creates a contamination entry point or a seal design challenge at the panel penetration.
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Compact Packaging Machine Frames
Drive shaft supports on compact packaging machine frames where the machine depth is controlled and any axial protrusion of the bearing inner ring beyond the panel face creates a clearance violation.
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Upgrade from NAF200 Where Protrusion Is a Problem
Drop-in housing upgrade from NAF200 where field installation shows the inner ring protrudes into a clearance violation. Housing J and bolt positions are compatible — replace only the housing and insert.
📦 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.
Engineering drawings must be submitted and approved before order confirmation. Catalogue dimensions are for reference only.
Frequently Asked Questions
Difference between NAF200 and NAFS200?
NAFS200 has a taller housing (higher A) that fully encloses the wide inner ring. NAF200 standard height may show inner ring protrusion at larger bores.
Can NAFS200 be used on a reversing drive?
No — same eccentric collar, same directional limitation as NAF200. Use UCF200 or UEF200 for reversing.
Is the bolt hole pattern the same as NAF200?
Yes — J and bolt size match. Housing height is taller, bolt positions unchanged.
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 NAFS200 Series
Provide shaft diameter, shaft rotation direction, bore type, and confirm whether inner ring clearance is a constraint in the installation. Contact us.
