Fasten the round bar directly
Fasten the D-CUT flat part
of the round bar
Used as an adjusting screw
When the round shaft is soft and the setscrew is harder, the outer diameter surface of the round shaft will be scratched. If the outer diameter surface of the round shaft is scratched, it will become difficult to move when readjusting the round shaft. In such a case, flatten the shaft as shown in Fig. 2.
(Fig. 1) Click the figure to see the enlarged view.
It is used when you do not want to scratch the outer diameter surface of the round shaft. However, it takes some time to align the setscrew with the D-CUT flat part of the round bar during assembly.
If you use the D-CUT flat part of the round bar to fasten it, you can also use a cone point setscrew or a cup point setscrew to bite the setscrew into the mating material and fasten it more firmly.
(Fig. 2) Click the figure to see the enlarged view.
Right-angle accuracy and flatness accuracy of the tip of the adjustment screw are important for the accuracy when adjusting the position. If the flat part of the tip of the adjusting screw is slanted or the flat surface is rough, no matter how accurately the adjusting screw is turned, the shaft cannot be adjusted accurately and finely.
And if you want to make finer adjustments, we recommend changing the screw pitch from coarse to fine.
(Fig. 3) Click the figure to see the enlarged view.
Fasten on a conical dint
Fasten on a concave groove
This is an example of how to use it as a setscrew for positioning in the longitudinal direction and the rotational direction by attaching a conical dent on the outer peripheral surface of the round shaft and dropping the pointed tip of the setscrew into it.
The standard tip angle of the pointed setscrew is 90 degree, but the one with the shortest setscrew length is 120 degree. Also, some people call the "cone point setscrew" the "conical setscrew".
(Fig. 4) Click the figure to see the enlarged view.
This is an example of how to use it as the setscrew for positioning in the longitudinal direction by making a concave groove (or V-shaped groove) around the outer peripheral surface of the round shaft and dropping the tip of cone point setscrew.
If the setscrew is harder than the round shaft, the round shaft will be damaged when the setscrew is tightened. After that, when the setscrew is loosened, the round shaft may not move smoothly.
(Fig. 5) Click the figure to see the enlarged view.
The tip of cone point setscrew is also used when it bite into the other party to stop that. In order to bite into the other party, the cone point setscrew tip must be harder than the other party.
The rotation of the round bar is regulated by the keyway and stopped in the longitudinal direction.
The rotation of the round bar is regulated by the keyway, and the longitudinal direction is free.
This is an example of how to use it for positioning in the longitudinal direction while controlling the rotation by dropping the tip of dog point setscrew into the keyway and stopping the bottom of the keyway at that tip.
This uses the dog point setscrew as the setscrew for a round bar with a keyway.
(Fig. 6) Click the figure to see the enlarged view.
This is an example of how to use the tip of dog point setscrew as a simple round key by dropping (floating) that tip into the keyway of the round bar.
This is one method used for structures that constrain the keyway shaft in the direction of rotation and allow it to move freely in the longitudinal direction.
(Fig. 7) Click the figure to see the enlarged view.
At this time, the tip of the dog point setscrew is not pressed (floating), so the following measures are required to fix the dog point setscrew. Each has advantages and disadvantages, but the horizontal screw method shown in Fig. 7 is complicated to process, but it is the preferred method as a mechanically reliable fixing method.
It is used in almost the same way as a flat point setscrew. Theoretically, the oval point setscrew hits the mating side at one point in the center of the screw tip, so it is unlikely that the mating material will kink when tightened.
It is similar to a cone point setscrew in that it hits the other side at one point in the center of the oval point setscrew tip. However, the oval point setscrew is characterized by being less likely to damage the other side and being less likely to deform its own tip.
Also, when adjusting the position by touching the tip of the setscrew to the flat surface on the other side, the oval point setscrew is effective for fine adjustment because the surface runout of the tip is small when it is turned.
However, if you need to make further fine adjustments when using the setscrew as an adjustment screw, we recommend that you use a finer screw thread.
It is a photograph and a figure of a brass adjustment screw with a oval tip of M2xP0.25 (finer screw thread).
(Reference: The screw pitch with a nominal diameter of M2 has a coarse screw thread is 0.4 mm and a fine screw thread is 0.25 mm.)
We manufacture the threaded part with a cutting tool, there is no problem in finer screw thread.
In addition, there is a difference in the R shape (dimensions) of the rounded tip between the old JIS standard (B1117-1980) and the new JIS standard (B1117-1988). The old JIS standard (B1117-1980) is a standard established in 1980, and the new JIS standard (B1117-1988) is a standard established in 1988.
I (Koji SAIDA) prefer the old JIS standard R shape in the figure on the left, so I adopted the old JIS standard R shape in the DEL standard.
Also, the oval point setscrew is in the JIS standard, but not in the ISO standard.
The oval point tip of the hexagon socket setscrew had a standard in the previous JIS standard (B1117-1988), but it is not in the JIS standard (B1117-1997) currently in use.
It is used to bite the cup tip of a cup point setscrew into the other party (flat surface or outer peripheral surface of the shaft) to stop it.
In order to damage the other party (flat surface or outer peripheral surface of the shaft), the setscrew tip must be harder than the other party.
Use the cup point setscrew or cone point setscrew when you want the tip of the setscrew to bite into the other party and attach it firmly.
Make the tip of the setscrew harder than the hardness of the other party.
If the shaft is scratched when you remove it later, it will be difficult to remove it, so use it when you do not want to scratch the shaft.
Flat point setscrews are recommended as a general shape.
It is necessary to make the hardness of the tip of a setscrew softer than the hardness of the other party.
If you cannot make such a difference in hardness, or if you want to fasten the outer circumference of the screw with a setscrew from the side, it is better to insert a "brass pusher" between the setscrew and the other party.