Gearmotors: What They Are and How to Size a Replacement
Many industrial loads need torque an electric motor can’t deliver on its own, at a
Availability:
2 in stock
Size 25 ball runner block, slimline SNH body 86.2 x 48 x 33.9 mm, C1 light preload, accuracy class N. Dynamic load capacity 28,600 N on a four-circuit design.
List Price
$79.99

2 in stock
On the Shelf & Ready to Ship
Ships same day by 6pm ET

No Risk, No Hassle
| MFR / Brand | Rexroth |
|---|---|
| MPN | R162121420 |
| Model | R 162121420 |
| Type | Linear Bearing |
|---|---|
| Preload | C1 (light preload) |
| Base Number | R162121420 |
| Industry Terms | runner block, ball runner block, linear carriage, linear guide block, ball carriage, linear bearing block, profiled rail guide, linear slide block, ball rail system, KWD block, Kugelwagen |
| Common Misspellings | R-162-121-420, R16212140, R162121240, KWD 25 SNH, Rexroth Rexroth runner block |
| Application Types | CNC machine axes, gantries and portals, pick-and-place and handling units, linear actuators, packaging and converting machinery, measuring and inspection stages, tool changers |
| Housing Style | Slimline (narrow) body, normal length, high height - SNH |
| Mpn Variants | R162121420, R-162-121-420, R162 121 420, R1621-214-20, 162121420, KWD-025-SNH-C1-N-1, KWD025SNHC1N1, KWD 025 SNH C1 N 1, KWD-25-SNH-C1-N-1 |
| Manufacturer Status | Active Bosch Rexroth catalogue part |
| Compatible With Replaces | Bosch Rexroth size 25 profiled ball guide rail, R1605 family, accuracy class N |
| Arrangement Configuration | Single size 25 slimline SNH runner block, four ball circuits |
| Precision Class | N (Normal accuracy class) |
| Min Temp | -10 °C |
| Dynamic Load Rating | 28,600 N per block (C, DIN ISO 14728-1, 100,000 m) |
| Static Load Rating | 35,900 N per block (C0) |
| Precision Rating | N (Normal accuracy class) |
| Max Temp | +80 °C |
| Bearing Type | Ball runner block (profiled rail linear guide) |
| Part Number | R162121420 / KWD-025-SNH-C1-N-1 |
| Rolling Elements | Recirculating steel balls, four circuits |
Bosch Rexroth R162121420, designation KWD-025-SNH-C1-N-1, is a size 25 ball runner block for the Rexroth Ball Rail System, a profiled-rail linear guide. Size: 25. Design: SNH, slimline width, normal length, high body. Preload Class: C1, light preload. Accuracy Class: N, Normal. Body Material: Carbon steel. Rolling Elements: Recirculating steel balls, four ball circuits. Ball Chain: none, balls retained by the block’s plastic retainers. Seals: SS standard. Self-Alignment: none, a rigid block. Lubrication: pre-lubricated with Rexroth Dynalub 510 bearing grease plus a preservative. A straight lube connection is supplied loose with the block. Unit Quantity: 1 Pc.
R162121420 — the Rexroth material number (MNR) printed on the carton label. R1621 is the runner block family prefix; the companion ball guide rails begin R1605.
KWD — ball runner block, Rexroth Ball Rail System.
025 — size 25, the number that matches the rail.
SNH — body geometry in the order width, length, height: S = slimline width, N = normal length, H = high body.
C1 — preload class C1, the light preload class.
N — accuracy class Normal.
1 — ball-retention option without a ball chain.
CS — carbon steel body, as printed on the carton (KUGELWAGEN CS / B.RUNNER BLOCK CS).
Size: 25. Overall Length of Runner Block: 86.2 mm. Width of Runner Block: 48 mm. Height of Runner Block: 33.9 mm. Dynamic Load Capacity C: 28,600 N. Static Load Rating C0: 35,900 N. Dynamic Torsional Moment Capacity Mt: 410 Nm. Dynamic Longitudinal Moment Capacity ML: 290 Nm. Static Torsional Moment Capacity Mt0: 510 Nm. Static Longitudinal Moment Capacity ML0: 360 Nm. Maximum Acceleration a max: 500 m/s². Coefficient of Friction: 0.002 to 0.003. Permissible Ambient Temperature: −10 °C to +80 °C. Dynamic load capacity C and the moment capacities Mt and ML are calculated on a 100,000 m stroke life per DIN ISO 14728-1. All figures are Bosch Rexroth configurator data for material number R162121420.
Height of Runner Block with Guide Rail: 40 mm. Guide Rail Hole Pitch T: 60 mm. Slimline blocks are through-bolted from above rather than flange-mounted. The carton holds one block in its poly bag, the Rexroth instruction leaflet R320103184 (2015-02 revision) and one loose straight grease nipple; the carton label reads 1 Stück/Pcs.
Mating Rail: Bosch Rexroth size 25 profiled ball guide rail, R1605 family, accuracy class N. Rexroth states that runner blocks and guide rails combine as desired within each accuracy class. Material number R162121420 and designation KWD-025-SNH-C1-N-1 identify the same part.
KWD is the Rexroth ball runner block, 025 is size 25, SNH is slimline width, normal length, high body, C1 is light preload, N is accuracy class Normal and 1 is the version without a ball chain.
Dynamic load capacity C is 28,600 N and static load rating C0 is 35,900 N, per Rexroth configurator data.
A Bosch Rexroth size 25 ball guide rail from the R1605 family, accuracy class N, with 60 mm hole pitch.
$30.91
2 in stock
$85.99
2 in stock
$23.06
1 in stock
$50.99
2 in stock
$85.99
2 in stock
$36.69
2 in stock
$22.91
2 in stock
Many industrial loads need torque an electric motor can’t deliver on its own, at a
Belt drives may appear simple, consisting of two wheels and a belt for power transfer.
Tapered, cylindrical, and spherical roller bearings all solve the same basic problem, carrying more load
Our team can locate, cross-reference, and source all parts.
Our team can locate, cross-reference, and source all parts.
Sort
Brand
Price
MPN
Categories