THK SSR25XSB Linear Guide Block
The THK SSR25XSB is a compact, short-block radial-type linear motion guide featuring a 4-row Gothic arch raceway structure with an integrated ball retainerTHK. It shares the identical cross-sectional dimensions with the standard SSR25XTB block but is engineered with a shorter overall length for space-saving installationsTHK. Optimized for high radial load capacity, it delivers exceptional rigidity, precision, and smooth motion.
The THK SSR25XSB is a compact, short-block radial-type linear motion guide featuring a 4-row Gothic arch raceway structure with an integrated ball retainer. It shares the identical cross-sectional dimensions with the standard SSR25XTB block but is engineered with a shorter overall length for space-saving installations. Optimized for high radial load capacity, it delivers exceptional rigidity, precision, and smooth motion. The ball cage eliminates ball-to-ball friction, enabling low noise, high-speed operation, and long-term maintenance-free performance. Its self-aligning DF (Direct Face) raceway design absorbs mounting errors while maintaining high accuracy.
2. Core Specifications
Basic Load Ratings
| Parameter | Value |
|---|---|
| Dynamic Load Rating (C, Radial) | 19.6 kN |
| Static Load Rating (C₀, Radial) | 26.3 kN |
| Allowable Moment Loads (Single Block) | Mx (Roll): 138 N·m, My (Pitch): 126 N·m, Mz (Yaw): 126 N·m |
| Max Rail Length | 3000 mm |
| Standard Rail Lengths | 55 – 3000 mm (increments of 50 mm) |
Block Dimensions (mm)
| Parameter | Value |
|---|---|
| Block Height (M) | 33 |
| Block Width (W) | 73 |
| Block Length (L) | 60 |
| Mounting Hole Thread (d₁) | M6 x 6.8 |
| Mounting Pitch (F) | 40 |
| Number of Mounting Holes | 4 (Bottom-mounted) |
| Lubrication Fitting | M6 (standard) |
| Weight (Block) | 0.830 kg |
Rail Specifications (mm)
| Parameter | Value |
|---|---|
| Rail Height (H) | 26 |
| Rail Width (W1) | 48 |
| Rail Mounting Hole Pitch | 60 mm (M6 tapped) |
| Rail Weight | 4.60 kg/m |
| Number of Raceways | 4 rows |
| Contact Angle | 90° (Radial) |
| Standard Preload | C0 (Clearance), C1 (Slight), C2 (Medium) |
| Operating Temperature | -10°C to 80°C |
| Standard Lubricant | THK AFG Grease |
| Material | High Carbon Chromium Bearing Steel (SUJ2) |
| Accuracy Classes | Normal (standard), H (High), P (Precision) |
3. Key Features (THK Official)
- Compact Short-Block Design: Shorter length (60mm) than standard XTB model, ideal for space-constrained mechanisms.
- Superior Radial Load Capacity: 4-row, 90° contact structure optimized for heavy radial loads in horizontal applications.
- Ball Retainer System: Prevents steel ball collision, reduces noise, enhances grease retention, and enables high-speed, low-dust motion.
- Self-Adjusting Capability: DF (Direct Face) circular-arc groove design automatically compensates for installation errors.
- High Precision & Rigidity: Minimized deflection under load; ensures stable, ultra-smooth linear motion.
- Long-Term Maintenance-Free: Sealed structure with long-life lubrication for extended service intervals.
- Versatile Mounting: Flange-type with bottom-mounted bolts for stable, rigid installation.
4. Standard Variants
- SSR25XSB: Standard short block, bottom mount, carbon steel.
- SSR25XSB-GK: With Germanium-containing solid lubricant (for low dust/low outgassing).
- SSR25XSB-SS: Stainless steel variant for corrosion-resistant environments.
- SSR25XTB: Standard-length block counterpart (longer, higher rigidity).
5. Typical Applications
- Machine Tools: CNC milling machines, vertical machining centers, grinding machines.
- Industrial Robots: Multi-axis arms, transfer lines, pick-and-place units.
- Semiconductor Equipment: Die bonders, wire bonders, inspection stages.
- Precision Machinery: Measuring instruments, printing presses, woodworking machines.
- Automation Equipment: High-speed actuators, assembly lines, conveying systems.
