Ball Screws

BSR Series Specifications and Options

• BSR miniature ball screw assemblies without integrated motors
• BSR catalog origin statement: made in America using both domestic and foreign material sources; precision-rolled 1050 steel ball screws
• BSR rolled ball screw diameters: 6mm, 8mm, and 10mm
• BSR rolled lead sizes: 1mm, 2mm, and 2.5mm
• Six standard BSR rolled sizes: 6mm × 1mm, 6mm × 2mm, 8mm × 1mm, 8mm × 2mm, 8mm × 2.5mm, and 10mm × 2mm
• Cylindrical, flanged, and externally threaded ball nut configurations
• Multi-liner ball-return system on cylindrical and flanged nuts
• Polymer wipers on cylindrical and flanged nuts help exclude debris and retain lubrication
• Standard backlash: 0.05mm maximum; preload and transitional-fit options available
• Ball nut static axial load rating up to 2.18 kN, depending on diameter and lead
• Configurable screw-end journals and end supports

Ball Screws with Externally Threaded Nuts

Externally threaded cylindrical ball screw nuts mount directly into internally threaded machine components, eliminating the external flange used on flanged nuts and reducing the space required around the nut. External-thread nut options are available with the threads on the left or right. These nuts do not include polymer wipers, helping preserve their compact threaded mounting profile.

Performance Benefits of Miniature Ball Screws

• Compact Design: Cylindrical nuts enable more compact assembly designs, while flange nuts offer easy mounting options.
• High Load Capacity: Ball nut static axial load ratings reach up to 2.18 kN, depending on diameter and lead.
• Debris Prevention: Polymer wipers at each nut end help keep out debris and retain lubrication.
• Versatile Mounting: Standard and special machined journals, along with fixed and floating end blocks, support diverse mounting needs.
• Customization Options: Custom ball screw designs are available for specific application requirements.
• Ease of Assembly: Available as assembled and unassembled units for flexibility during machine assembly.
• Durability: The multi-liner ball-return system supports smooth, long-lasting operation.
• Backlash Options: Standard fit nuts have 0.05mm maximum backlash; reduced-backlash nuts are available with 0.013mm maximum backlash and no preload; transitional-fit nuts range from ≤0.008mm backlash to <3% preload.

Ground Ball Screw Specifications

• Ground nut styles: flanged and square
• Flanged-nut ground ball screws: 4mm, 6mm, 8mm, 10mm, and 12mm screw diameters, with 1mm, 2mm, 5mm, 6mm, and 8mm lead options across the lineup
• Square-nut ground ball screws: 6mm and 8mm screw diameters with 1mm lead
• Accuracy grades: Grade 3 and Grade 5
• Load ratings across the ground family: 420–2,200 N dynamic and 570–4,900 N static; square-nut models range from 560–650 N dynamic and 950–1,300 N static
• Overall lengths: 60–240mm for flanged-nut models and 90–160mm for square-nut models

Ball Screw Linear Actuator Specifications and Options

• Ball screw linear actuators for controlled, load-carrying linear motion, with integration level varying by series
• BS and BE Series external-nut actuator configurations; TSM Series integrated step-servo ball screw actuator configurations
• BS/BE frame sizes include NEMA 08, 11, 14, 17, and 23; TSM frame sizes include NEMA 08, 11, 17, and 23
• BS Series catalog-listed screw diameters: 6mm, 8mm, and 10mm, with compatibility depending on motor size and configuration
• BS Series catalog-listed lead options: 1mm, 2mm, and 2.5mm
• BS Series: cylindrical and flanged ball nut configurations; BE Series: multiple nut options depending on screw and motor configuration
• BSR/BS catalog accuracy grades: Grade 5, Grade 7, and Grade 10; catalog V300p tolerances over 300mm are 23µm, 52µm, and 210µm respectively
• BS Series standard backlash: 0.05mm maximum; preload optional
• BS Series ball nut static axial load ratings up to 2.18 kN; BS motor mechanical axial limits vary by motor frame size
• BS Series polymer wipers help exclude debris and retain lubrication
• BS Series standard and custom machined journals available on one or both screw ends
• BS Series fixed and floating end blocks available for screw support, alignment, and thermal expansion
• BS Series standard BSR sizes: 6mm × 1mm, 6mm × 2mm, 8mm × 1mm, 8mm × 2mm, 8mm × 2.5mm, and 10mm × 2mm
• BE Series screw diameters: 4mm, 6mm, 8mm, 10mm, and 12mm
• BE Series lead options: 1mm, 2mm, 2.5mm, 4mm, 5mm, 8mm, and 10mm, depending on screw diameter and motor frame
• BE Series frame sizes: NEMA 08, 11, 14, 17, and 23, with multiple motor body lengths and nut options
• BE Series ball screws use a gothic-arch groove profile; preload can reduce axial clearance to zero for increased rigidity
• BE Series transmission efficiency is listed at over 90%
• BE Series customization includes ball screw length, end machining, nut style, and mounting options

Miniature Ball Screw Linear Actuators - BS Series

Miniature ball screw linear actuators use small-diameter ball screws to convert rotary motor motion into precise linear movement in compact automation systems. The BS Series uses an external-nut configuration in which the motor rotates the ball screw, forcing a restrained external ball nut to travel axially along it. The BS Series combines miniature NEMA motors, precision ball screws, and factory-aligned components in established configurations.

Available with NEMA 08, 11, 14, 17, and 23 motor frame sizes, BS Series configurations use 6mm, 8mm, and 10mm diameter ball screws depending on motor size and configuration. The BSR/BS catalog identifies these ball screws as precision-rolled 1050 steel and lists Grade 5, Grade 7, and Grade 10 accuracy options. PBC Linear also uses an automated straightening process to control ball screw runout and straightness.

Unlike lead screw actuators, ball screw actuators use recirculating steel balls between the screw and nut to reduce friction, increase efficiency, and support higher-speed motion with less drive torque. This makes miniature ball screw actuators well suited for compact machines that need accurate positioning, smooth travel, and durable performance in a small package.

BE Series Ball Screw Driven Linear Actuators

The BE Series products are designed around hybrid step motors, ball screws, and nuts to provide high torque, high precision, and high efficiency. The series uses an external-nut ball screw shaft architecture and is offered in NEMA 08, 11, 14, 17, and 23 frame sizes with multiple motor lengths and nut options.

The BE Series configuration table expands the motorized ball screw range to 4mm, 6mm, 8mm, 10mm, and 12mm nominal screw diameters. Available lead options include 1mm, 2mm, 2.5mm, 4mm, 5mm, 8mm, and 10mm depending on screw diameter and motor frame. The data sheet documents standard model configurations as well as additional configurable and custom options.

TSM Series Integrated Step-Servo Ball Screw Actuators

The TSM Series integrates the ball screw, drive, encoder, and controller into the stepper motor to provide an all-in-one ball screw actuator solution. The current TSM data sheet lists four frame sizes - NEMA 08, 11, 17, and 23 - with multiple ball screw options and standardized product models for quick response. Closed-loop step-servo control provides position and velocity feedback, while the integrated architecture reduces the number of separate motion-control components required in the machine.

TSM Series Specifications and Options

• TSM08: 4mm screw diameter with 1mm lead
• TSM11: 6mm screw diameter with 1mm, 2mm, 6mm, or 10mm leads
• TSM17: 8mm screw diameter with 1mm, 2mm, 2.5mm, 5mm, 8mm, or 12mm leads
• TSM23: 10mm screw diameter with 2mm or 4mm leads, and 12mm screw diameter with 2mm, 4mm, 5mm, or 10mm leads
• TSM08, TSM11, and TSM17 catalog accuracy options include C5/C7, with B08025 listed as C7 only; TSM23 is listed as C7
• Operating temperature listed for TSM08, TSM11, TSM17, and TSM23: 0°C to +50°C
• TSM17/23 use a 20,000-count/rev encoder and TSM11 uses a 4,096-count/rev encoder for closed-loop positioning
• Integrated controls support functions such as pulse command, programmable motion, and Modbus/RTU depending on model
• TSM17/23 fieldbus products support RS-485/Modbus-RTU daisy-chain communication
• Standardized configurations are documented for quick response, with additional customized configuration options available

Ball Screw Linear Actuator Performance Benefits

• Compact Design: BS Series cylindrical-style nuts allow for a compact assembly, while BE Series configurations provide multiple nut and motor-size options to fit space-constrained applications.
• Versatile Compatibility: The BS Series uses six standard BSR diameter-and-lead combinations, while the BE Series expands the range to 4–12mm screw diameters and lead options from 1–10mm depending on configuration. Both series span NEMA 08, 11, 14, 17, and 23 frame sizes.
• High Performance: Ball screw architectures reduce friction and support efficient motion; the BE Series data sheet lists transmission efficiency at over 90%.
• Robust Load Handling: For the BS Series, motor mechanical axial limits vary by frame size: 135 N for NEMA 8 and 11, 320 N for NEMA 14 and 17, and up to 1,050 N for NEMA 23.
• Debris Protection: BS Series polymer wipers at each nut end help prevent the ingress of debris and particulates, supporting durability and service life.
• Precision and Rigidity: BS Series standard no-preload configurations hold backlash to 0.05mm maximum; the BE Series gothic-arch groove profile can be preloaded to reduce axial clearance to zero for increased rigidity.
• Customization and Flexibility: BS Series options include standard and special machined journals, fixed or floating supports, and assembled or unassembled configurations. BE Series customization includes ball screw lengths, end machining, nut style, and mounting options.
• Integrated Motion Control: TSM Series combines the ball screw, motor, drive, encoder, and controller in one actuator platform, with closed-loop step-servo control for precise positioning, smooth operation, and responsive motion.
• Durability: BS Series wipers support debris resistance, while the BE Series data sheet specifies heat-treated screw, nut, and ball materials with minimum ball screw component hardness at 58 HRC.