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Micro screw manufacturer in Japan
FURIYA GIKEN CO.,LTD.
TEL：055-236-2011
eigyo@furiya.co.jp（Japanese）
nakaune@furiya.co.jp（English）
PAT.
Developed based on user feedback
fixf4®
Newly designed self-locking screw
PAT.
1.Developed based on user feedback
"Is there a way to prevent screws from loosening without using screw-locking adhesive?" We developed fixf4® in response to a request from an experienced engineer at a camera company.
With fixf4®, there's no need for screw-locking adhesive, and it also helps to reduce costs.
It is perfect for assembling metal enclosures and peripheral components.
It can also replace W-SEMS (screws with built-in washers).
This prevents the tilting of screws caused by spring washers and reduces the short breakdowns in production lines caused by overlapping of flat washers during screw alignment in screw feeders. This makes it ideal for automating screw tightening and reducing product weight.
2.Ratio of torque converted to clamping load
It is often mentioned that when tightening a screw:
- 50% of the applied torque is lost due to friction at the head of the screw.
- 40% of the applied torque is lost due to friction at the threads.
- Only 10% of the applied torque is actually converted into the clamping
load that holds the parts together.
To prevent screws from loosening, a screw locking adhesive is applied to the threads. This increases the frictional force of the threads. However, increasing the frictional force of the threads also reduces the ratio of torque converted to clamping load.
In addition, the screw-locking adhesive:
-could peel off and remain inside the product.
-cannot be used repeatedly.
-is higher in cost than screws.
W-SEMS (screws with built-in washers) is commonly used as a self-locking screw with its bigger bearing surface and clamping load by the spring washer because it is more cost-effective than screw-locking adhesives.
Spring washer
W-SEMS
However, W-SEMS:
-is heavier.
-is not effective as a self-locking screw when the elastic deformation of the spring washer does not work properly.
-can be easily diagonal due to the spring washer.
-cannot be picked up from the screw feeder when washers overlap each other.
Easity diagonal
Hard to pick up
fixf4® addresses issues with screw-locking adhesives and W-SEMS by reducing thread friction and increasing “clamping load” from elastic stress at the Elastic phase.
3. Product Features
Asymmetrically shaped threads
＜Rundown phase＞
The 20° thread of fixf4®, as opposed to the 30° female thread, reduces the frictional force on the screw threads, enabling easy screwing with low resistance to the nut.
＜Elastic phase＞
The low resistance during screwing and the elastic stress generated when the thread tip is pressed against the female thread increase the clamping load, resulting in a significant anti-loosening effect.
※The threads should not be deformed like the illustration above.
4.Product Performance
-High anti-loosening effect
-Low screw-in torque
-Significant cost reduction due to the absence of screw-locking adhesives
-Lighter weight due to the absence of built-in washers
-Prevents screws from diagonal tightening due to the absence of built-in
washers
-No adhesive peel-off
5.Loosening toruque comparison
fixf4® has a higher loosening torque than the Nylon patch and is equivalent to W-SEMS.
6. Specifications
fixf4® has proven its effectiveness for both miniature and larger screws.
（Possible materials）
-
SWCH (low carbon steel commonly used in Asia)
-
SUSXM7（SUS304 with cupper）
-
SUS410
7. Applications
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