Left Hand Ball Screw
A left hand ball screw has a thread helix that runs in the opposite direction from a standard right hand ball screw. When both screws rotate in the same direction from the same reference orientation, their nuts travel in opposite axial directions.
The main reason for selecting a left hand ball screw is therefore the required motion direction-not a difference in accuracy or load capacity. It is used when the machine layout, drive arrangement or paired motion requires reverse, mirrored or opposing linear travel.
Available Left Hand Ball Screw Options
| Item | Available Option |
|---|---|
| Thread Direction | Left hand thread, normally identified as LH |
| Standard Accuracy | Rolled C7 |
| Optional Accuracy | Ground C5 |
| Screw Shaft Material | S55C |
| Ball Nut Material | 20CrMo |
| Screw Length | Cut according to the required overall length |
| Shaft-End Machining | According to BK/BF, FK/FF or EK/EF support arrangements, or a customer drawing |
| MOQ | 1 piece for available standard specifications; non-standard requirements subject to confirmation |
Available left hand models include 1605, 2005, 2505, 3205, 3210, 4005, 4010 and 5010. Other diameter, lead and nut combinations must be confirmed before quotation.
When Is a Left Hand Ball Screw Required?
Reverse Motion Direction
A left hand ball screw is used when the nut must travel in the opposite direction from a conventional right hand screw under the same drive rotation. This may be required by the motor position, transmission arrangement or machine control logic.
Opposing Motion from One Drive
A left hand screw can be paired with a right hand screw so that two nuts move toward each other or away from each other while the screws are driven together. This arrangement is useful in centering, opening and closing mechanisms.
Mirrored Machine Layout
Two mechanically mirrored axes may require opposite thread directions to produce symmetrical movement without adding another reversing mechanism.
Restricted Installation Space
In a compact machine, the motor or bearing arrangement may only fit on one side. A left hand screw can provide the required travel direction without relocating the complete drive system.
Left Hand and Right Hand Ball Screw Motion
Left hand and right hand ball screws differ in the direction of the thread helix. This difference changes the relationship between screw rotation and nut travel.
| Comparison | Right Hand Ball Screw | Left Hand Ball Screw |
|---|---|---|
| Thread Helix | Right hand | Left hand |
| Normal Identification | Usually treated as the standard direction | Should be clearly marked LH |
| Nut Travel | Travels in one axial direction for a given screw rotation | Travels in the opposite axial direction under the same reference rotation |
| Typical Use | Conventional single-axis transmission | Reverse, mirrored or opposing motion |
Neither thread direction is inherently more accurate or stronger. Accuracy, load capacity and rigidity depend on the ball screw model, nut structure, preload and manufacturing grade-not on whether the thread is left hand or right hand.
For a more detailed comparison, read Left Hand vs Right Hand Ball Screw .
Typical Applications
Left hand ball screws are mainly used where the required motion direction cannot be achieved conveniently with a standard right hand configuration.
•Dual-sided clamping: Left hand and right hand screws move two clamping elements toward or away from the center.
•Opening and closing mechanisms: Two moving parts travel symmetrically in opposite directions.
•Mirrored automation axes: Paired mechanisms reproduce symmetrical linear movement.
•Special CNC mechanisms: Reverse feed direction is required by the motor or transmission layout.
•Compact linear stages: The drive position is fixed, but the nut must travel in the opposite direction.
Important Selection Notes
Thread direction should be confirmed explicitly during selection and quotation. A left hand nut cannot be installed on a right hand screw, even when the diameter and lead are the same.
•Mark the required thread direction as LH on the drawing or purchase order.
•Confirm the screw diameter, lead and complete nut model.
•Use direction arrows to show the required nut movement for the specified motor rotation.
•For paired left hand and right hand screws, confirm the center positions, total travel and synchronization method.
•Provide a dimensioned drawing when shaft-end machining is required.
Vertical-axis note: A left hand ball screw does not make a vertical axis self-locking. A brake motor, counterbalance or other suitable holding and anti-fall device is still required according to the machine design.
Information Required for Quotation
Please provide the following information when requesting a left hand ball screw:
•Complete ball screw and nut model
•Nominal diameter and lead
•Left hand thread requirement
•Total screw length and required stroke
•C7 or C5 accuracy grade
•Shaft-end machining drawing
•Required quantity
Left Hand Ball Screw FAQ
Q: How can I identify a left hand ball screw?
A: Check the direction of the thread helix and the model identification. A left hand specification should be clearly marked LH on the drawing, label or purchase order. If the direction is uncertain, send clear photographs and a motion-direction diagram for confirmation.
Q: Can a left hand nut be used on a right hand screw?
A: No. The screw and nut must have the same thread direction, diameter, lead and matching ball-track geometry.
Q: Does a left hand ball screw have lower accuracy?
A: No. Thread direction does not determine the accuracy grade. DLY left hand ball screws are available in rolled C7 and ground C5 options according to the specification.
Q: Can left hand and right hand screws be driven together?
A: Yes. When correctly arranged and synchronized, the two nuts can move toward each other or away from each other under a common drive. The complete mechanical layout must be checked before production.
Q: Can DLY machine the shaft ends?
A: Yes. Both ends can be machined according to the selected support-unit arrangement or a dimensioned customer drawing.
Request a Left Hand Ball Screw Quote
Send the required model, diameter, lead, total length, accuracy grade, shaft-end drawing and quantity for confirmation.
Email: export@dlybearing.com
Hot Tags: left hand ball screw, China left hand ball screw manufacturers, suppliers, factory, stainless steel ball screw, ball screw 20mm, 2500mm ball screw, electric ball screw, ball screw end, 32mm ball screw
