BK17 THK Ball Screw Support Unit

THK square fixed-side support unit for ball screws with a 17 mm bearing journal diameter.

The BK17 contains a factory-preloaded P5 angular-contact bearing set in a DF arrangement, providing accurate shaft positioning and high axial rigidity. Its compact housing allows straightforward installation without additional bearing adjustment.

The unit is supplied complete with its housing, bearing set, holding lid, collars, seals, lock nut and locking screw.

Product characteristics

Category: Ball screw support units
Manufacturer: THK
Series: BK
Design: Square support unit
Mounting position: Fixed side
Bearing journal diameter: 17 mm
Bearing arrangement: DF angular-contact arrangement
Bearing accuracy: P5
Bearing used: 7203 equivalent
Preload: Factory adjusted
Weight: 1.270 kg
Country of origin: Japan

Main dimensions

Shaft diameter d: 17 mm
Length L: 35 mm
L1: 9 mm
L2: 44 mm
L3: 7 mm
Housing width B: 86 mm
Housing height H: 64 mm
Housing thickness b: 43 mm
Shaft centre height h1: 39 mm ±0.02 mm
B1: 50 mm
H1: 55 mm
E: 28 mm
Mounting-hole pitch P: 68 mm
C1: 19 mm
C2: 8 mm
Square dimension T: 24 mm

Mounting-hole dimensions

Through-hole diameter d1: 9 mm
Counterbore diameter d2: 14 mm
Counterbore depth h: 8.5 mm
Holding-lid thread M: M4

Collar dimensions

Collar outside diameter D: 23.4 mm
Collar thickness t: 7 mm

Load ratings

Basic dynamic axial load rating Ca: 13.7 kN
Static permissible axial load: 5.85 kN
Axial rigidity: 125 N/μm

Components supplied

Housing: 1
Precision bearing set: 1
Holding lid: 1
Collars: 2
Seals: 2
Lock nut: 1
Hexagonal socket-head locking screw with set piece: 1

The BK17 is designed for the fixed end of a ball screw and can be paired with a THK BF17 supported-side unit.