GRUB SCREW

A Grub screw is also known as a blind screw or a set screw. These are generally used 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. The most obvious point of distinction between grub screws and other types of standard screws and bolts is that true grub screws tend not to feature a protruding head. Instead, they’re usually threaded right to the top these are having the same diameter along their length, which means that the grub screw can be fully driven into its hole to sit flush with (or even countersunk into, depending on the application) the workpiece.

The design of grub screws is intended to offer a secure gripping or joining facility without the use of a nut, as opposed to the typical arrangement found with most bolts. Despite this key difference, grub screws function much more effectively. Because they’re fully threaded and designed to be driven into an existing tapped hole or socket than driven into the surface, creating a new hole. These are commonly considered as a type of bolt, although with a few key differences.

The different shaped tips have different properties that engineers can utilize. The most common type is the cup point & cone point. Cup point 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.

ASME, BS, DIN, ISO, UNI, DIN-IN