THKSRS15MSSE+470LMMiniature Caged-Ball Linear Guide Assembly — 15 mm Rail Width, 43 mm Block, 470 mm Rail, Stainless, 1 Block + 1 Rail

Product Description

What this part is

A THK Caged Ball LM Guide in the miniature SRS series, size 15, supplied as a matched assembly — one LM block already fitted to one 470 mm LM rail. SRS is the most compact family in THK’s Caged Ball LM Guide range: a four-way equal-load design that carries radial, reverse-radial and lateral load equally, with a synthetic-resin ball cage holding the balls apart instead of letting them run ball-to-ball. Block, rail and balls are stainless steel as standard on this series.

Decoding the order code

SRS — Caged Ball LM Guide, miniature type, four-way equal load, top-surface block mounting
15 — size, meaning a 15 mm LM rail width
M — medium block length: 43 mm overall block, 20 mm bolt pitch along travel. The short S block is 32 mm and the long N block is 60.8 mm on the same rail
SS — contact end seals fitted at both ends of the block
+470L — LM rail length, 470 mm

SRS15 rails are drilled on a 40 mm mounting-hole pitch, so a 470 mm rail carries a full run of mounting holes. THK’s standard maximum SRS15 rail length is 2000 mm.

What these specs mean in practice

The ball cage is what separates this series from an uncaged miniature guide. Balls never touch one another, so the ball-to-ball scuffing and the ticking noise of a full-complement block are gone, and grease sits in the cage pockets instead of being squeezed out of the raceway. That buys long grease life and quiet, even running, which is why SRS turns up in inspection stages, pick-and-place heads and medical or semiconductor handling axes where an operator works next to the machine.

Stainless block, rail and balls make the series usable in wash-down and clean-room work with no added coating. The trade-off against a steel size-15 profile guide is capacity: 6.66 kN dynamic is a small-payload number. The M block is the middle choice on length — more moment capacity than the short S block, roughly a third of the moment capacity of the long N block.

Published ratings and mounting data

Basic dynamic load rating C — 6.66 kN, radial direction
Basic static load rating C0 — 5.70 kN
Static permissible moment, one block — MA 26.2 N·m, MB 26.2 N·m, MC 40.4 N·m
Block height — 16 mm
Block width — 32 mm
Block length — 43 mm with SS seals fitted
Block mounting holes — four M3, 3.5 mm deep, on 25 mm across travel by 20 mm along travel
Rail width — 15 mm, tolerance 0 to –0.02 mm
Rail height — 9.5 mm
Rail mounting-hole pitch — 40 mm
Rail counterbore — 3.5 mm through, 6 mm counterbore, 4.5 mm deep, for M3 bolts
Rail length supplied — 470 mm
Seal resistance — 1.00 N per block with SS seals
Grease nipple designation — PB107
Service temperature — –15 °C to 80 °C
Mass — block 0.047 kg, rail 0.96 kg per metre

Quantity and configuration

Sale unit is 1 Pc: one SRS15M block on one 470 mm SRS15 rail. THK counts a single-rail unit as one set, so a two-rail parallel axis takes two of these.

Installation and setup notes

Keep the block on the rail. Run a miniature caged-ball block off the end of its rail and the ball train drops out of the raceway; it cannot be reloaded without a temporary arbor. Bolt the rail down along its whole length working from one end so the rail is pulled straight, then torque the block bolts with the load bracket free, so the block is not dragged out of alignment by the payload. Lubricate through the block lubrication hole and use it for grease only. On SRS15 the PB107 grease nipple is specified at order time rather than fitted as standard, so plan on greasing through the hole if no nipple is present.

Interchange guidance

Miniature profile rail guides are not cross-brand interchangeable. Raceway groove geometry, ball diameter and rail bolt pitch all differ between makers, so an SRS15M block will not run on another maker’s 15 mm miniature rail and their block will not run on this rail. Buy the block and rail together, which is how this is sold. Within THK, SRS15S and SRS15N run on this same rail and share its hole pattern — shorter and longer blocks respectively. Those are related sizes on a common rail, not equivalents to the M block, because block length changes both load and moment capacity. SRS15GM is the uncaged full-complement version of the same envelope, again a related size rather than the same product.