Manufactured by CHG Bearing, the NN 3008 KTN/UP is a precision Super-Precision Cylindrical Roller Bearings. Key dimensional parameters include a 40 mm bore diameter, a 68 mm outer diameter, and a 21 mm overall width. This component is designed to meet standard load requirements and ensure consistent operational performance. For comprehensive technical evaluation, please explore the detailed specifications, dimensional data, product images, and CAD drawings provided below. A complete PDF data sheet is also readily available for direct download to support your engineering and procurement needs.
NN 3008 KTN/UP - Super-Precision Cylindrical Roller Bearings
Technical Specifications
| Overview | |
|---|---|
| Part Number | NN 3008 KTN/UP |
| Brand | CHG® |
| Characteristics | |
| Bearing Type | Super-precision Cylindrical Roller Bearing |
| Design Type | Tapered Bore 1:12 |
| Structure (Drawing Reference) | Complete Bearing |
| Number of Rows | 2 |
| Ring Type | None |
| Design | NN Design |
| Tolerance Class | UP |
| Bearing Material | Bearing Steel |
| Coating | None |
| Sealing | None |
| Lubricant | None |
| Features | None |
| Number of Flanges – Outer Ring | 0 |
| Number of Ribs – Inner Ring | 3 |
| Dimensions | |
| Bore Diameter (d) | 40 mm |
| Width (B) | 21 mm |
| Outer Diameter (D) | 68 mm |
| Minimum Chamfer Dimension rmin | 1 mm |
| Inner Ring Chamfer | 1 mm |
| Outer Ring Chamfer | 0.6 mm |
| End-face Height Difference h | 1.5 mm |
| Inner-Ring Land Diameter (L1 / d1) | 50.6 mm |
| Outer Ring Raceway Diameter E | 61 mm |
| Shaft Shoulder Diameter dₐ, min. | 45 mm |
| Housing Shoulder Diameter Dₐ, min. | 62 mm |
| Housing Shoulder Diameter Dₐ, max. | 63 mm |
| Performance | |
| Basic Dynamic Load Rating C (kN) | 42.9 kN |
| Basic Static Load Rating C₀ (kN) | 56 kN |
| Limiting Speed – Grease (r/min) | 13000 r/min |
| Limiting Speed – Oil-air (r/min) | 15000 r/min |
| Reference Grease Quantity Gref (cm³) | 1.8 cm³ |
| Fatigue Load Limit Pᵤ (kN) | 6.4 kN |
| Axial Static Stiffness – Guideline Value (N/µm) | 890 N/µm |
| Material | |
| Weight (kg) | 0.278 kg |
| Radial Internal Clearance | C1 mm |
| Internal Design & Weight | |
| Cage Type | Non-metallic Cage |
| Mounting Dimensions | |
| Lubrication Port Thread / Size Φ1 | 59.9 |
NN 3008 KTN/UP 68 mm 40 mm 21 mm Frequently Asked Questions about NN 3008 KTN/UP Super-Precision Cylindrical Roller Bearings
Find key technical answers regarding dimensions, specifications, and replacement options for this model.
The Open Type engineered for NN 3008 KTN/UP by CHG Bearing utilizes precision non-contact metal shields or reinforced NBR/FKM contact lip seals. This barrier prevents particulate ingress, washdown fluids, and abrasive dust from reaching the raceways while eliminating grease leakage under centrifugal forces.
To safeguard CHG Bearing NN 3008 KTN/UP against fretting wear and false brinelling during transport or vibration, assemble mating surfaces (40 mm x 68 mm) using anti-fretting mounting paste. Maintaining strict alignment and avoiding prolonged static vibration will preserve raceway polish.
When fitting NN 3008 KTN/UP over a 40 mm shaft, CHG Bearing strictly recommends uniform induction heating (controlled between 90°C and 110°C) or precision hydraulic press sleeves. Under no circumstances should direct impact blows be struck against the rings or cage, as shock loads cause brinelling indents and premature spalling.
Sourcing NN 3008 KTN/UP directly from CHG Bearing eliminates intermediate brokerage markups while granting you factory-direct engineering backup, rigorous ISO-certified quality assurance, competitive volume wholesale pricing, and dependable supply chain stability for Super-Precision Cylindrical Roller Bearings.
