Caged ball linear guide unit SCR series

25 mm65 mm30 mm

Product Overview
The SCR is a cross (orthogonal) caged-ball LM guide enabling X‑Y motion without a conventional saddle. Four rows of balls circulate in precision‑ground raceways in the LM rail and integrated LM block. Two rails intersect at right angles and are combined into a single block with the internal structure of the caged-ball SHS family, providing a compact orthogonal LM system for simplified X‑Y assemblies.

Highlight Feature Tags

• Long-term maintenance free
• High accuracy
• 4-way equal load
• Cross

Available Sizes
15, 20, 25, 30, 35, 45, 65

Basic Load Rating (summary)
Basic dynamic load rating: 14.2 to 253 kN (size-dependent)
Basic static load rating: 24.2 to 408 kN (size-dependent)

Structure and Features
Balls run in four rows of precision-ground raceways on both the LM rail and the integrated LM block. Ball cages and end plates in the block allow continuous circulation. Two rails intersect at right angles within a single block, enabling an orthogonal LM system with a single SCR block for space-saving X‑Y motion.

4-Way Equal Load
Each ball row has a 45° contact angle so load ratings on the LM block are equal in four directions (radial, reverse-radial and lateral), allowing operation in any orientation.

High Rigidity
Four-row balance of balls provides high moment resistance and smooth linear motion even under preload to increase rigidity. The integrated SCR block offers greater rigidity than two conventional blocks bolted back-to-back, making it suitable for high‑rigidity X‑Y tables.

Example of Using an Inner Saddle
Inner saddle configurations are supported; the SCR design permits simplified X‑Y assemblies without conventional external saddles.

Dimensional drawing / Dimensional table (selected table structure)
Table columns: Model No. | Outer dimensions (Height M, Width W, Length L1) | LM block dimensions (B1, B3, B4, B, C, C1, S×ℓ, L2, H3, N, E, Grease nipple) | LM rail dimensions (W1, W2, M1, Pitch F, Mounting hole d1×d2×h) | Basic load rating (C kN, C0 kN) | Static permissible moment (M0, MB) | Mass (LM block kg, LM rail kg/m)

Representative rows (values shown per row in the page table)
SCR15 — Outer dims: 47 / 48 / 64.4 | ... | Grease nipple: PB1021B | LM rail pitch F: 60 | Mounting hole: 4.5×7.5×5.3 | Basic dynamic C: 14.2 kN | Basic static C0: 24.2 kN | Mass LM block: 0.54 kg | Mass LM rail: 1.3 kg
SCR20 — Outer dims: 57 / 59 / 79 | ... | LM rail pitch F: 60 | Mounting hole: 6×9.5×8.5 | Basic dynamic C: 22.3 kN | Basic static C0: 38.4 kN | Mass LM block: 0.334 kg | Mass LM rail: 0.88 kg
SCR25 — Outer dims: 57 / 78 / 98 | ... | LM rail pitch F: 60 | Mounting hole: 6×9.5×8.5 | Basic dynamic C: 28.1 kN | Basic static C0: 50.3 kN | Mass LM block: 0.473 kg | Mass LM rail: 1.7 kg
SCR30 — Outer dims: 70 / 88 / 109 | ... | LM rail pitch F: 60/80 (model dependent) | Mounting hole: 7×11×9 | Basic dynamic C: 36.8 kN | Basic static C0: 64.7 kN | Mass LM block: 0.696 kg | Mass LM rail: 3.4 kg
SCR35 — Outer dims: 82 / 105 / 131 | ... | LM rail pitch F: 80/105 | Mounting hole: 9×14×12 | Basic dynamic C: 54.2 kN | Basic static C0: 88.8 kN | Mass LM block: 1.15 kg | Mass LM rail: 4.6 kg
SCR45 — Outer dims: 95 / 123 / 152 | ... | Mounting hole: 9×14×12 | Basic dynamic C: 72.9 kN | Basic static C0: 127 kN | Mass LM block: 2.01 kg | Mass LM rail: 6.8 kg
SCR65 — Outer dims: 180 / 226 / 272 | ... | Mounting hole: 18×26×22 | Basic dynamic C: 253 kN | Basic static C0: 408 kN | Mass LM block: 11.9 kg | Mass LM rail: 13.3 kg

Standard Lengths and Maximum Lengths of LM Rails (overview)
Standard rail lengths (examples per model):
SCR15: 160, 220, 280, 340, 400, 460, 520, 580, 640, 700, 760, 820, 940, 1000, 1060, 1120, 1180, 1240, 1360, 1480, 1600 mm
SCR20: 220, 280, 340, 400, 460, 520, 580, 640, 700, 760, 820, 940, 1000, 1060, 1120, 1180, 1240, 1360, 1480, 1600, 1720, 1840, 1960, 2080, 2200 mm
SCR25/30/35/45/65: standard lengths vary by model up to multiple meters; unit: mm
Maximum lengths: SCR models commonly available up to 3,000 mm; some SCR45 pitches up to 3,090 mm.

Tapped-Hole LM Rail Type
Some SCR rail variations are bottom-tapped so the X‑axis rail can be fastened from the top. Tap sizes and effective depths by model: 15 (M5, depth 8), 20 (M6, depth 10), 25 (M6, depth 12), 30 (M8, depth 15), 35 (M8, depth 17), 45 (M12, depth 20), 65 (M20, depth 30).

Notes on Dimensional Table
Length L includes contamination-protection accessories where applicable; adding accessories or lubricators increases total block length. Static permissible moment definitions: M0 = one block static permissible moment.

Characteristics / Technical specifications

• Brand: THK
• Model family: SCR
• Product type: Cross (orthogonal) Caged Ball LM Guide
• Available nominal sizes: 15, 20, 25, 30, 35, 45, 65
• Basic dynamic load rating (C): 14.2 to 253 kN (size-dependent)
• Basic static load rating (C0): 24.2 to 408 kN (size-dependent)
• LM rail standard pitch F examples: 60 mm (small sizes), 80 mm, 105 mm, 150 mm (larger sizes)
• LM rail standard lengths: multiple standard lengths per model; maximum length up to 3,000 mm (model-dependent)
• Tapped-rail options: bottom-tapped rails available (tap sizes M5 to M20 depending on model)
• Grease nipple: model-dependent (some models use grease nipple PB1021B; grease nipple not installed if QZ lubricator is used)
• Mass examples: LM block mass ranges from ~0.16–11.9 kg depending on model; LM rail mass ranges from ~0.175–13.3 kg/m depending on model
• Special features: 4-way equal load (45° contact angle rows), high rigidity, capable of X‑Y motion without additional saddle