SFU2005 Ball Screw

The SFU2005 ball screw has a 20 mm nominal screw diameter and a 5 mm lead, meaning that the nut travels 5 mm for each complete revolution of the screw. It uses a standard flanged single-nut structure with a built-in ball return path.

DLY offers two SFU2005 nut configurations: SFU2005-3 with three circulation circuits and SFU2005-4 with four circulation circuits. The four-circuit version has a longer nut body and higher dynamic load, static load and rigidity ratings.

SFU2005-3 and SFU2005-4 Specifications

Specification	SFU2005-3	SFU2005-4
Nominal Screw Diameter	20 mm	20 mm
Lead	5 mm	5 mm
Ball Diameter	3.175 mm	3.175 mm
Nut Outer Diameter D	36 mm	36 mm
Flange Outer Diameter A	58 mm	58 mm
Flange Thickness B	10 mm	10 mm
Nut Length L	43 mm	51 mm
Flange Width W	47 mm	47 mm
Mounting Hole Diameter X	6.5 mm	6.6 mm
Mounting Hole Center Distance H	44 mm	44 mm
Mounting Thread Q	M6	M6
Number of Circuits	3	4
Dynamic Load Ca	860 kgf	1,130 kgf
Static Load Coa	1,710 kgf	2,380 kgf
Rigidity K	22 kgf/μm	25 kgf/μm

Dimensions are in millimetres. Load ratings are in kgf. Confirm the complete nut drawing before designing the mounting interface.

Difference Between SFU2005-3 and SFU2005-4

Both versions use the same 20 mm screw diameter, 5 mm lead, 36 mm nut outer diameter and 58 mm flange outer diameter. The main differences are the nut length, number of circulation circuits and load rating.

•SFU2005-3: Three circulation circuits and a 43 mm nut length. Its shorter nut body is useful when the available installation space is limited.

•SFU2005-4: Four circulation circuits and a 51 mm nut length. It provides higher dynamic load, static load and rigidity ratings than SFU2005-3.

When replacing an existing SFU2005 nut, do not confirm the product from "2005" alone. Check the nut length and circulation number to distinguish the two versions.

Product Structure and Materials

Item	SFU2005 Specification
Nut Structure	Standard flanged single nut
Ball Return System	Built-in ball return path
Screw Shaft Material	S55C
Ball Nut Material	20CrMo
Standard Accuracy	Rolled C7
Optional Accuracy	Ground C5
Thread Direction	Right-hand as standard; left-hand available
MOQ	1 piece

Accuracy and Shaft-End Machining

The rolled C7 version is the standard SFU2005 option and is suitable for general CNC machinery, automation equipment, packaging machines and linear modules. A ground C5 version is available when the application requires higher lead accuracy.

The screw can be cut to the required length, and both ends can be machined according to the customer's drawing. The drawing should clearly show the bearing-seat diameters, shoulders, threads, keyways, flats and other installation dimensions.

BK/BF, FK/FF and EK/EF support units can be selected according to the final shaft-end design. The support-unit model should be confirmed together with the machined-end dimensions.

Typical SFU2005 Applications

With its 20 mm screw diameter, 5 mm lead and standard flanged nut, SFU2005 is used for controlled linear movement in equipment such as:

•CNC machines and engraving equipment

•Industrial automation equipment

•Packaging machinery

•Linear modules and positioning axes

Suitability must still be checked against the required stroke, rotational speed, axial load, installation direction and duty cycle.

Information Required for Quotation

Please provide the following information when requesting an SFU2005 quotation:

•SFU2005-3 or SFU2005-4

•Total screw length

•C7 or C5 accuracy grade

•Right-hand or left-hand thread

•Shaft-end machining drawing

•Required quantity

SFU2005 Ball Screw FAQ

Q: What do the numbers in SFU2005 indicate?

A: "20" indicates a nominal screw diameter of 20 mm, while "05" indicates a lead of 5 mm.

Q: Are SFU2005-3 and SFU2005-4 interchangeable?

A: Not necessarily. They have the same basic screw diameter and lead, but their nut lengths, number of circulation circuits and load ratings are different. The mounting space and existing nut dimensions must be checked before replacement.

Q: Can DLY machine the SFU2005 screw ends?

A: Yes. The screw can be cut to length and both ends can be machined according to a dimensioned drawing.

Q: Is SFU2005 available in C5 accuracy?

A: Yes. Rolled C7 is the standard option, and a ground C5 version is available according to the required specification.