Precision Lead Screw Assemblies for Linear Motion Systems

DLY Precision Lead Screw Assemblies are ball screw-based transmission sets configured according to the installation structure, stroke, load, speed and positioning requirements of the equipment. A typical assembly can include a ball screw and nut, machined shaft ends, support units and a coupling.

Instead of selecting each component separately, customers can provide a drawing or machine specification and ask DLY to confirm the ball screw series, diameter, lead, accuracy grade, end-machining dimensions and matched accessories.

Available configurations: ball screw and nut, customized shaft-end machining, BK/BF, FK/FF or EK/EF support units, and a matched coupling.

Available Assembly Components

Component	Available Options	Selection Information
Ball screw and nut	SFU, SFA, SFE, SFY, DFU, DFI, SCI, SCM and other available series	Confirm diameter, lead, accuracy, preload requirement, overall length and stroke
Shaft-end machining	Stepped ends, bearing seats, threads, keyways, flats and other drawing-based features	Provide a dimensioned drawing showing tolerances and mating parts
Support units	BK/BF, FK/FF and EK/EF series	Select according to the screw diameter, end-machining dimensions and mounting structure
Coupling	Flexible, diaphragm, jaw or rigid coupling, subject to application confirmation	Confirm motor shaft diameter, ball screw shaft diameter, torque and operating speed
Nut housing	Available according to the selected nut type and mounting dimensions	Confirm nut model, mounting-hole pattern and equipment interface

Ball Screw Options

The ball screw is the main transmission component within the assembly. DLY supplies different ball screw structures for applications with different installation, load, speed and accuracy requirements.

Item	Available Selection
Manufacturing Type	Rolled or ground ball screw
Common Accuracy	Rolled C7 and ground C5; other accuracy grades can be confirmed according to the project
Available Accuracy Grades	C0, C3, C5, C7 and C10, subject to the ball screw series and manufacturing method
Common Leads	4, 5 and 10 mm; other leads depend on the selected series and diameter
Screw Shaft Material	S55C
Nut Material	20CrMo
Maximum Length	Up to approximately 6000 mm, depending on diameter, accuracy and machining requirements
MOQ	1 set for available standard configurations; non-standard projects require confirmation
Warranty	1 year

The final configuration depends on the selected ball screw series and operating conditions. Not every diameter, lead, accuracy grade, preload option or length is available for every series.

SFU ball screw specifications for precision lead screw assemblies

Rolled and Ground Ball Screw Assemblies

Rolled C7 Ball Screw Assembly

Rolled C7 ball screws provide a practical balance between positioning performance, availability and cost. They are commonly selected for general automation equipment, packaging machinery, material-handling systems and other industrial linear motion applications.

Ground C5 Ball Screw Assembly

Ground C5 ball screws can be selected where tighter lead accuracy and more consistent positioning performance are required. The complete assembly should be designed with suitable support bearings, alignment, preload and installation rigidity to make effective use of the selected accuracy grade.

View more available ball screw series before confirming the assembly configuration.

Support Unit and End-Machining Matching

Ball screw shaft ends must match the selected support units and motor-side connection. DLY can process the fixed and supported ends according to BK/BF, FK/FF or EK/EF mounting dimensions, or according to a customer-supplied drawing.

Bearing seats and stepped shaft ends
Internal and external threads
Keyways and flat surfaces
Motor-side coupling connection
Fixed-side and supported-side dimensions

DLY can supply matching ball screw support units to help reduce dimensional matching errors between the screw shaft and bearing supports.

Information Required for Selection

To confirm a suitable precision lead screw assembly, please provide as much of the following information as possible:

Required screw diameter and lead
Total screw length and effective travel
Horizontal, vertical or inclined installation
Maximum axial load and operating speed
Required positioning or lead accuracy
Required preload or allowable axial clearance
Support unit models or mounting dimensions
Motor shaft diameter and coupling requirement
Dimensioned shaft-end machining drawing
Required quantity

If a complete drawing is not available, provide the equipment structure, stroke, load, speed and motor information so that the main component dimensions can be checked.

Typical Applications

CNC machine feed systems
Industrial automation equipment
Packaging and assembly machinery
Inspection and positioning equipment
Material-handling mechanisms
Linear stages and customized motion systems

The suitability of each assembly depends on the actual operating conditions. Load capacity, critical speed, buckling strength, service life and thermal expansion should be checked according to the selected ball screw model and installation arrangement.

Precision Lead Screw Assemblies FAQ

Q: What is included in a precision lead screw assembly?

A: A typical DLY assembly can include a ball screw and nut, customized shaft-end machining, fixed-side and supported-side support units, and a coupling. The exact supply scope is confirmed according to the order.

Q: Is the motor included?

A: The standard supply scope does not automatically include a motor. Please state whether a motor, motor bracket or other installation component is required so that availability can be confirmed separately.

Q: Can DLY machine the ball screw ends according to my drawing?

A: Yes. DLY supports drawing-based shaft-end machining. Please provide the complete dimensions, tolerances, threads, keyways and mating-component information for review.

Q: Can I choose between rolled and ground ball screws?

A: Yes. Rolled C7 ball screws are commonly used for general industrial motion, while ground C5 ball screws can be selected for applications requiring tighter lead accuracy. Availability depends on the requested model and dimensions.

Q: How do I select the correct support units?

A: Support units are selected according to the screw diameter, shaft-end dimensions, axial load, mounting direction and required rigidity. The support unit dimensions must match the machined ends of the ball screw.

Q: Can one complete set be ordered?

A: One set can be supplied for available standard configurations. For non-standard ball screws or special machining requirements, the minimum order quantity must be confirmed after reviewing the drawing.