Product Details
DLY SFNU nuts are flange-type ball screw nuts designed for precision linear transmission. They work with matching ball screw shafts to convert rotary motion into smooth and accurate linear movement, making them suitable for CNC equipment, automation systems, packaging machines, measuring devices and other motion control applications.
Compared with standard SFU nuts of comparable shaft size, SFNU nuts generally use a longer nut body and provide higher dynamic and static load ratings. This makes SFNU a stronger choice when the application requires better load capacity, rigidity and service life while still keeping a compact flange mounting structure.
The model number shows the basic screw size. For example, SFNU1605 is used with a 16 mm diameter ball screw and 5 mm lead, while SFNU1610 is used with a 16 mm diameter ball screw and 10 mm lead. For replacement projects, please confirm the shaft diameter, lead, nut length, flange dimensions, mounting hole size and load requirement before ordering.
Product Parameters
DLY SFNU/SFU flange ball screw nuts are supplied in a wide range of diameters and leads for precision linear transmission systems. The dimensional and load rating data below provides key information for model selection, including nut size, flange mounting dimensions, dynamic load rating, static load rating and rigidity.
SFNU DIN 69051 FORM B Construction Levels Series Specification Size Table
Unit: mm
| Model | Shaft Diameter d | Lead | Ball Diameter | D | A | B | L | W | H | X | Q | n | Dynamic Rating Load | Static Rating Load | Rigidity kgf/μm |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SFNU01605-4 | 16 | 5 | 3.175 | 28 | 48 | 10 | 45 | 38 | 40 | 5.5 | M6 | 1x4 | 1380 | 3052 | 32 |
| SFNU01610-3 | 16 | 10 | 3.175 | 28 | 48 | 10 | 57 | 38 | 40 | 5.5 | M6 | 1x3 | 1103 | 2401 | 26 |
| SFNU02005-4 * | 20 | 5 | 3.175 | 36 | 58 | 10 | 51 | 47 | 44 | 6.6 | M6 | 1x4 | 1551 | 3875 | 39 |
| SFNU02505-4 * | 25 | 5 | 3.175 | 40 | 62 | 10 | 51 | 51 | 48 | 6.6 | M6 | 1x4 | 1724 | 4904 | 45 |
| SFNU02510-4 | 25 | 10 | 4.762 | 40 | 62 | 12 | 80 | 51 | 48 | 6.6 | M6 | 1x4 | 2954 | 7295 | 50 |
| SFNU03205-4 * | 32 | 5 | 3.175 | 50 | 80 | 12 | 52 | 65 | 62 | 9 | M6 | 1x4 | 1922 | 6343 | 54 |
| SFNU03210-4 * | 32 | 10 | 6.35 | 50 | 80 | 12 | 85 | 65 | 62 | 9 | M6 | 1x4 | 4805 | 12208 | 61 |
| SFNU04005-4 | 40 | 5 | 3.175 | 63 | 93 | 14 | 55 | 78 | 70 | 9 | M8 | 1x4 | 2110 | 7988 | 63 |
| SFNU04010-4 | 40 | 10 | 6.35 | 63 | 93 | 14 | 88 | 78 | 70 | 9 | M8 | 1x4 | 5399 | 15500 | 73 |
| SFNU05010-4 * | 50 | 10 | 6.35 | 75 | 110 | 16 | 88 | 93 | 85 | 11 | M8 | 1x4 | 6004 | 19614 | 85 |
| SFNU06310-4 ° | 63 | 10 | 6.35 | 90 | 125 | 18 | 93 | 108 | 95 | 11 | M8 | 1x4 | 6719 | 25358 | 99 |
| SFNU08010-4 ° | 80 | 10 | 6.35 | 105 | 145 | 20 | 93 | 125 | 110 | 13.5 | M8 | 1x4 | 7346 | 31953 | 109 |
| SFU01204-4 | 12 | 4 | 2.5 | 24 | 40 | 10 | 40 | 32 | 30 | 4.5 | - | 1x4 | 902 | 1884 | 26 |
| SFU01604-4 | 16 | 4 | 2.381 | 28 | 48 | 10 | 40 | 38 | 40 | 5.5 | M6 | 1x4 | 973 | 2406 | 32 |
| SFU02004-4 | 20 | 4 | 2.381 | 36 | 58 | 10 | 42 | 47 | 44 | 6.6 | M6 | 1x4 | 1066 | 2987 | 38 |
| SFU02504-4 | 25 | 4 | 2.381 | 40 | 62 | 10 | 42 | 51 | 48 | 6.6 | M6 | 1x4 | 1180 | 3795 | 43 |
| SFU02506-4 | 25 | 6 | 3.969 | 40 | 62 | 10 | 54 | 51 | 48 | 6.6 | M6 | 1x4 | 2318 | 6057 | 47 |
| SFU02508-4 | 25 | 8 | 4.762 | 40 | 62 | 10 | 63 | 51 | 48 | 6.6 | M6 | 1x4 | 2963 | 7313 | 49 |
| SFU03204-4 | 32 | 4 | 2.381 | 50 | 80 | 12 | 44 | 65 | 62 | 9 | M6 | 1x4 | 1296 | 4838 | 51 |
| SFU03206-4 | 32 | 6 | 3.969 | 50 | 80 | 12 | 57 | 65 | 62 | 9 | M6 | 1x4 | 2632 | 7979 | 57 |
| SFU03208-4 | 32 | 8 | 4.762 | 50 | 80 | 12 | 65 | 65 | 62 | 9 | M6 | 1x4 | 3387 | 9622 | 60 |
| SFU04006-4 | 40 | 6 | 3.969 | 63 | 93 | 14 | 60 | 78 | 70 | 9 | M6 | 1x4 | 2873 | 9913 | 66 |
| SFU04008-4 | 40 | 8 | 4.762 | 63 | 93 | 14 | 67 | 78 | 70 | 9 | M6 | 1x4 | 3712 | 11947 | 70 |
| SFU06320-4 ° | 63 | 20 | 9.525 | 95 | 135 | 20 | 149 | 115 | 100 | 13.5 | M8 | 1x4 | 11444 | 36653 | 112 |
| SFU08020-4 ° | 80 | 20 | 9.525 | 125 | 165 | 25 | 154 | 145 | 130 | 13.5 | M8 | 1x4 | 12911 | 47747 | 138 |
| SFU10020-4 ° | 100 | 20 | 9.525 | 150 | 202 | 30 | 180 | 170 | 155 | 17.5 | M8 | 1x4 | 14303 | 60698 | 162 |
Notes:
Left thread can be made if marked with * mark.
For model availability or special requirements, please confirm with DLY before ordering.
SFU01204-4 nut is standard without wiper.
Product Features
Longer Nut Body for Higher Load Support
SFNU ball screw nuts are designed with a longer nut body than standard SFU nuts in comparable sizes. This structure provides higher dynamic and static load ratings, making SFNU nuts suitable for linear motion systems that require stronger axial load support, better rigidity and longer service life.
Compact Internal Circulation Structure
The internal ball circulation design keeps the nut body compact and avoids external return tubes. This helps reduce interference with surrounding machine components and makes SFNU nuts easier to install in CNC machines, automation equipment, positioning tables and other space-limited assemblies.
Flange Mounting for Stable Assembly
The flange structure allows the nut to be fixed directly to a moving table, bracket, slide or actuator component. This mounting style is widely used in precision feed systems because it provides a clear installation interface and supports stable linear movement under repeated operation.
Smooth Rolling Transmission
Rolling contact between the balls, screw shaft and nut reduces friction compared with sliding screw mechanisms. With proper lubrication and installation, SFNU nuts can support smooth movement, efficient transmission and reliable positioning performance in continuous motion applications.
Clear Model Selection for Different Ball Screw Sizes
SFNU models are selected according to shaft diameter and lead, such as SFNU1605, SFNU1610, SFNU2505 and SFNU3210. For new equipment design or replacement projects, the screw diameter, lead, nut length, flange dimensions, mounting holes, load rating and installation space should be considered together.
Suitable for Complete Ball Screw Assemblies
DLY can supply SFNU nuts together with matching ball screw shafts, end machining and support units according to machine drawings or application requirements. This helps improve assembly compatibility and reduces the risk of selecting mismatched transmission components.
Application Scenarios
SFNU ball screw nuts are used where the linear transmission system needs smooth movement, stable load support and reliable flange mounting. The final model should be selected according to stroke, speed, load, mounting space and required service life.
CNC Machine Feed Axes
Used on milling machines, engraving machines, routers and other feed systems where positioning accuracy and repeatable linear movement are required.
Automation Positioning Units
Suitable for linear stages, transfer units, loading equipment and automatic assembly mechanisms that need stable motion under repeated cycles.
Packaging and Conveying Equipment
Used for pushing, positioning, lifting and adjustment mechanisms in packaging machinery and material handling systems.
Inspection and Measuring Devices
Applied in precision adjustment tables, measuring equipment and test machines where smooth feed and low backlash are important.
Vertical and Load-Sensitive Axes
For axes with higher axial load or rigidity requirements, SFNU nuts can be considered when the standard SFU nut is not strong enough.
Replacement and Maintenance Projects
Useful for replacing worn ball screw nuts when the machine requires the same mounting interface but better load support or longer service life.
FAQ
Q: What is an SFNU nut?
A: An SFNU nut is a flange-type ball screw nut with an internal ball circulation structure. It is mounted on a matching ball screw shaft to convert rotary motion into linear motion.
Q: What is the difference between SFNU nuts and SFU nuts?
A: SFNU and SFU nuts belong to the same flange-type ball screw nut family, but SFNU nuts usually have a longer nut body and higher dynamic and static load ratings in comparable shaft sizes. SFU nuts are more common for standard compact applications, while SFNU nuts are better for higher load or higher rigidity requirements.
Q: How do I read the model number SFNU1605?
A: SFNU1605 means the nut is used with a 16 mm diameter ball screw and 5 mm lead. SFNU1610 means 16 mm diameter and 10 mm lead. The exact nut length, flange size and mounting hole dimensions should still be checked in the parameter table.
Q: Can I replace an SFU nut with an SFNU nut?
A: Not always. Although they are similar flange ball screw nuts, the length, load rating and sometimes mounting dimensions may be different. Before replacement, confirm the shaft diameter, lead, flange size, total nut length, mounting holes and available installation space.
Q: What information should I provide for selection?
A: Please provide the ball screw diameter, lead, required stroke, load, speed, installation direction, accuracy requirement and current nut model or drawing. For replacement, photos of the old nut and screw assembly are also helpful.
Q: Can DLY supply the SFNU nut together with the ball screw shaft?
A: Yes. DLY can help match the SFNU nut with the corresponding ball screw shaft and support end machining according to the drawing or machine installation requirements.
Need Help Confirming an SFNU Ball Screw Nut?
Send DLY your required model, ball screw diameter, lead, nut dimensions or existing drawing. Our team can help confirm whether SFNU, SFU or another ball screw nut type is more suitable for your application.
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