What is Set Screw
set screw
What is Set screw ( Grub screw )
A set screw also known as a blind screw or a grub screw is a type of screw generally used as a detent to secure an object within or against another object usually without using a nut . The most common examples are securing a pulley or gear to a shaft. Set screws are headless. it means that the screw is full thread and has no head projecting past the thread’s major diameter.If a set screw does have a head, the thread will extend all the way to the head (whereas a bolt might have an unthreaded shank between the head and thread). A set screw is almost always driven with an internal-wrenching drive, such as a hex socket (Allen), star (torx), square socket (Robertson), or a slot. The set screw passes through a threaded hole in the outer object and is tightened against the inner object to prevent it from moving relative to the outer object. It exerts compressional or clamping force through the bottom tip that projects through the hole.
Point types
This advertisement from 1913 illustrates various set screw point types Set screws appear with a variety of tip (point) types. The different shaped tips have different properties that engineers can utilize. If an engineer were to use a detent to ensure proper nesting of the screw, they might choose to use a cone point type of screw. One might often need to use a flat point when the screw must press perfectly flat against a surface.The most common type is the cup point. This type works well because the surface is rounded so that a small surface area is in contact, but it does not have extremely high stress at one point like that of a cone point. Durability studies show that the cup point offers superior resistance to wear while maintaining a strong grip.Knurled cup points offer the added advantage of a locking action (similar to that of a serrated lock washer) that prevents the screws from working loose in high-vibration applications.M16x60 Din 916 Hexagon Socket Set Screw With Cup Point
Common points include the following:
- Flat point
- Domed point
- Cone point
- Cup point
- Extended point (pilot point, dog point)
- Knurled cup point
Drive types
Set screws have a variety of drive styles, including the following:
- Straight slot
- Hex socket
- Square socket
- External hex
- External square
- Bristol spline
The common Set screw standard include following:
The most used material include following:
- Stainless steel 304 A2-70
- Stainless steel 316 A4-80
- Alloy steel at grade 45H, 8.8 10.9 12.9
- Carbon Steel
- H65 brass.
cup point set screwvisit wikipedia to find more about set screws