Silicon nitride ceramic sleeve is a custom-machined Si₃N₄ shaft sleeve or bushing, produced in inner diameters from around 5 mm up to 120 mm and lengths up to about 300 mm, with optional fine grinding and polishing. It is used in chemical dosing pumps, mechanical seals, deep hole drilling tools and electric motor bearings where wear resistance, dimensional stability and electrical insulation are required.
Silicon Nitride Ceramic Sleeve Specifications
| Silicon Nitride Ceramic Sleeve | ||||
| Item NO. | Outer Diameter (mm) | Inner Diameter(mm) | Length (mm) | Purity |
| AT-SNB-0001 | 20 | 12 | 43 | 85-99 |
| AT-SNB-0002 | 17 | 9 | 43 | 85-99 |
| AT-SNB-0003 | 15 | 10 | 45 | 85-99 |
| AT-SNB-0004 | 19 | 11 | 47 | 85-99 |
| AT-SNB-0005 | 23 | 13 | 51 | 85-99 |
| AT-SNB-0006 | 24 | 14 | 58 | 85-99 |
| AT-SNB-0007 | 28 | 20 | 61 | 85-99 |
| AT-SNB-0008 | 30 | 22 | 68 | 85-99 |
| AT-SNB-0009 | 32 | 26 | 70 | 85-99 |
| AT-SNB-0010 | 37 | 30 | 72 | 85-99 |
| AT-SNB-0011 | 43 | 35 | 83 | 85-99 |
| AT-SNB-0012 | 48 | 40 | 108 | 85-99 |
| AT-SNB-0013 | 59 | 45 | 108 | 85-99 |
| AT-SNB-0014 | 70 | 35 | 108 | 85-99 |
| AT-SNB-0015 | 76 | 40 | 120 | 85-99 |
| AT-SNB-0016 | 93 | 80 | 124 | 85-99 |
Choose the Sleeve by Its Function
The same cylindrical shape can serve different tasks. First identify which part rotates, where contact occurs and which surfaces locate the sleeve in the assembly.
| Requested part | Motion / functional position | Selection information |
|---|---|---|
| Shaft protection sleeve | Rotates with the shaft; its outer surface may work against an adjacent seal or contact component | Shaft fit, axial retention, working OD, end details and the adjacent component |
| Fixed bearing bushing | Located in a housing; its bore works against a rotating or sliding mating part | Housing fit, working bore, mating material, running clearance, load, speed and lubrication |
| Seal-adjacent / locating sleeve | Supports the drawing-defined seal location or axial position | Assembly section, shoulders, sealing or locating interfaces and required alignment |
| Guide/fixture bushing | Guides a tool or moving component through a controlled bore | Tool size, fixture datum, guide length, working clearance and coolant/particle conditions |
Silicon Nitride Ceramic Sleeve Properties
| Property | Unit/condition | AD-SIN-ST | What it is used for |
|---|---|---|---|
| Material form | Sintered structural ceramic | Tubes, rotors, rings and machined structural parts | Confirms the grade family for a machined sleeve or bushing |
| Bulk density | g/cm³; typical | 3.2 | Component mass and balance estimates |
| Flexural strength | MPa; typical | 700 | Grade comparison and wall-section discussion |
| Fracture toughness, KIC | MPa·m½; method-dependent | 6.5 | Edge-chipping and impact-loading discussion during assembly and service |
| Rockwell hardness | HRA; typical | 92–94 | Working-surface and contact-pair comparison |
| Apparent porosity | vol% | <0.3 | Seal-adjacent and cleaning conditions |
| Poisson's ratio | Dimensionless | 0.25 | Preliminary contact-stress and interference-fit review |
| Thermal conductivity | W/(m·K) | 20 | Heat path at a seal-adjacent or sliding interface |
Compare Silicon Nitride with Alternative Sleeve Materials
Silicon Nitride vs. Silicon Carbide
- Silicon nitride: Generally offers greater fracture toughness for impact-prone or edge-loaded contacts.
- Silicon carbide: Offers higher stiffness and thermal conductivity where these properties govern the design.
Silicon Nitride vs. Alumina
- Silicon nitride: Consider for demanding mechanical contacts requiring greater toughness.
- Alumina: An economical option for general wear applications under moderate operating conditions.
Silicon Nitride vs. Metal
- Reasons to consider ceramic: Corrosion, galling or sliding wear that limits metal sleeve life.
- Assembly requirements: Review alignment, edge loading and temperature changes. Ceramic sleeves require different handling and fitting practices.
Compare under the same conditions: Use the same geometry, mating materials and service medium. Confirm grade-specific compatibility, tolerances and clearances against the assembly drawing.
Si3N4 Sleeve Packaging
- Each silicon nitride ceramic sleeve is wrapped in a protective film or bag to avoid surface scratches.
- Sleeves are separated with foam or custom separators to prevent contact damage during transit.
