THK SSR20XTB Linear Guide Block
The THK SSR20XTB is a robust, flange-type linear guide block from the SSR radial series, designed for bottom-mounted installation. It features a 4-row Gothic arch raceway with a 90° contact angle, optimized for exceptional radial load capacity and rigidity. Equipped with THK's patented ball retainer (cage) system, it eliminates ball-to-ball friction, ensuring low noise, high-speed operation, and long-term maintenance-free performance.
1. Product Overview
The THK SSR20XTB is a robust, flange-type linear guide block from the SSR radial series, designed for bottom-mounted installation. It features a 4-row Gothic arch raceway with a 90° contact angle, optimized for exceptional radial load capacity and rigidity. Equipped with THK's patented ball retainer (cage) system, it eliminates ball-to-ball friction, ensuring low noise, high-speed operation, and long-term maintenance-free performance. Its self-aligning DF (Direct Face) raceway design effectively absorbs mounting surface errors while maintaining superior precision and stability.
2. Core Specifications
Basic Load Ratings
| Parameter | Value |
|---|---|
| Dynamic Load Rating (C, Radial) | 19.6 kN |
| Static Load Rating (C₀, Radial) | 23.4 kN |
| Allowable Moment Loads (Single Block) | Mx (Roll): 82 N·m, My (Pitch): 75 N·m, Mz (Yaw): 75 N·m |
| Max Rail Length | 3000 mm |
| Standard Rail Lengths | 73 – 3000 mm (50 mm increments) |
Block Dimensions (mm)
表格
| Parameter | Value |
|---|---|
| Block Height (M) | 28 |
| Block Width (W) | 59 |
| Block Length (L) | 66.5 |
| Mounting Hole Thread (d₁) | M6 x 9 |
| Mounting Pitch (F) | 46.6 |
| Number of Mounting Holes | 4 (Bottom-mounted) |
| Lubrication Fitting | B-M6F (M6) |
| Weight (Block) | 0.720 kg |
Rail Specifications (mm)
| Parameter | Value |
|---|---|
| Rail Height (H) | 24 |
| Rail Width (W1) | 42 |
| Rail Mounting Hole Pitch | 60 mm (M6 tapped) |
| Rail Weight | 3.30 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
- Flange Type, Bottom-Mount Design: Ideal for tables where top-mounted through-holes cannot be drilled, providing secure, rigid fastening.
- Superior Radial Load Performance: 4-row, 90° contact structure engineered for heavy radial loads in horizontal applications.
- Caged Ball Technology: Prevents steel ball collision, reduces noise & heat, improves grease retention, enabling high speeds & extended life.
- Self-Alignment (DF Design): Unique circular-arc grooves compensate for installation errors, ensuring smooth, accurate motion.
- High Rigidity & Precision: Minimized deflection under load for stable, ultra-precise linear movement.
- Maintenance-Free: Sealed construction with long-life lubrication for extended service intervals.
- Compact & Versatile: Optimized cross-section for space-efficient designs in various automated machinery.
4. Standard Variants
- SSR20XTB: Standard flange block, bottom mount, carbon steel.
- SSR20XTBM: With side seals (UU) for enhanced dust/water protection.
- SSR20XTB-SS: Stainless steel variant for corrosion-resistant environments.
- SSR20XTB-GK: Equipped with solid lubricant (Germanium) for cleanroom/low-dust applications.
5. Typical Applications
- Industrial Automation: Assembly lines, pick-and-place machines, conveying systems.
- Machine Tools: CNC routers, small milling machines, grinding machines.
- Semiconductor Equipment: Precision inspection stages, die bonders.
- Measuring Instruments: High-precision testers, optical alignment devices.
- Robotics: Cartesian robots, transfer mechanisms.
