All About NUT

 What is a Nut.. ?

A nut is a mechanical fastener with a threaded hole. It is attached to a bolt, screw or stud to provide a clamping force and prevent axial movement. For example, a bolt is inserted through two parts, with aligned holes, and a nut is then screwed onto the bolt. The shaft of the bolt prevents radial movement of the parts, while the head of the bolt and the nut together prevent axial movement.

Types of Nut

There are several types of Nuts available in market as per the requirement criteria,

Lets discuss some of them

1. Hex Nut

The most common type of nut is the hex nut. This has a hexagonal outer shape for the faces of tools to apply torque when fastening. To provide a secure fastening, this type of nut typically relies on torque being applied to generate an axial force. This axial force causes sufficient friction at the threads so as to prevent the nut from unscrewing. The force may act between the bolt head and the nut, causing compression of the parts being fastened. Alternatively, it may act between a pair of adjacent nuts, allowing parts to be fastened more loosely.

2. Jam Nut

A jam nut is a low profile type of nut, typically half as tall as a standard nut. It is commonly used as a type of lock nut, where it is "jammed" up against a standard nut to lock the two in place. It is also used in situations where a standard nut would not fit.

A jam nut is often used when a nut needs to be locked in place without clamping against another object. The jam nut essentially acts as the "other object", as the two nuts are tightened against each other. They can also be used to secure an item on a fastener without applying force to that object. This is achieved by first tightening one of the nuts onto the item. Then the other nut is screwed down on top of the first nut. The inner nut is then slackened back and tightened against the outer nut.

Jam nuts can also be used in situations where a threaded rod must be rotated. Since threaded rods have no bolt heads, it is difficult or impossible to apply torque to a threaded rod. A pair of jam nuts is used to create a point where a wrench may be used.

3. Square Nut

A square nut is a four-sided nut. Compared to standard hex nuts, square nuts have a greater surface in contact with the part being fastened, and therefore provide greater resistance to loosening. They are also much less likely to become rounded-off after repeated loosening/tightening cycles. Square nuts are typically mated with square-headed bolts. Square nuts are used along with flat washers in order to avoid damage from its sharp edges and increase the strength of the fastener.

4. Eye Nut

Eye nuts are fasteners with a looped head. They are designed to receive a hook or rope. Eye nuts are rated for different types of applications and are oval or round in shape. Load-rated eye nuts are designed for vertical lifting, but are not recommended for use with angular lifts. Eye nuts that are not load-rated are designed for use with tie downs and guiding wires. They are not rated for lifting applications.

5. Wing Nut

A wing nut, wing nut or butterfly nut is a type of nut with two large metal "wings", one on each side, so it can be easily tightened and loosened by hand without tools.

6. Lock nut

This types of nuts are generally used in ball screws, The attached washer helps nut to lock with the screw with a specified tightened location. 

7. Tee Nut

A T-nut or tee nut (also known as a blind nut, which can however also refer to a rivet nut or an insert nut is a type of nut used to fasten a wood, particle or composite materials work piece, leaving a flush surface.

It has a long, thin body and a flange at one end, resembling a T in profile. The flanges of T-nuts often have hooks or serrations on the prongs that dig into a wooden work piece as the bolt is tightened from the opposite side of the piece, providing better retention.

8. Coupling Nut

A coupling nut, also known as extension nut, is a threaded fastener for joining two male threads, most commonly a threaded rod but also pipes. The outside of the fastener is usually a hex so a wrench can hold it. Variations include reducing coupling nuts, for joining two different size threads; sight hole coupling nuts, which have a sight hole for observing the amount of engagement; and coupling nuts with left-handed threads. These are used to make up long rod assemblies from shorter lengths of rods. The rods are threaded into the coupling nut for a certain distance

9.  Castle nut

A castellated nut, sometimes referred to as a castle nut, is a nut with slots (notches) cut into one end.  The name comes from the nut’s resemblance to the crenelated parapet of a medieval castle. Castellated nuts are sometimes referred to incorrectly as castigated nuts.

10. Slotted Nut

Slotted nuts differ slightly from castellated nuts. Castellated nuts are formed with a round section at the top where the slots are located. Slotted nuts do not have this rounded modification. The flat sides of slotted nuts extend fully from the top to the bottom of the nut. Both castellated and slotted nuts are designed to use a pin (usually a cotter pin) that fits through the slots and through a hole in the screw to which the nut is attached. This pin prevents the nut from turning and loosening. Compared with slotted nuts, castellated nuts allow the cotter pin to be confined closer to the margins of the nut itself, providing added sereneness.

11. Kep Nut

Keps Nuts, or K Lock Nuts, are hex nuts pre-assembled with a free spinning external tooth lock washer. The locking action is achieved when the nut is tightened against a bearing surface as the teeth of the washer dig into it. The K-Lock Nut is the most popular type of lock nut because of its versatility, cost, and ease of installation.

12. Nylon Nut

The nylon collar insert is placed at the end of the nut, with an inner diameter (ID) slightly smaller than the major diameter of the screw. The screw thread does not cut into the nylon insert, however, the insert deforms elastically over the threads. The insert locks the nut against the screw as a result of friction, caused by the radial compressive force resulting from the deformation of the nylon. Nyloc nuts retain their locking ability up to 250 °F (121 °C)

13. Cap Nut

An Cap nut, also referred to as crown hex nut, blind nut, acorn nut, domed cap nut, or dome nut , is a nut that has a domed end on one side. When used together with a threaded fastener with an external male thread, the domed end encloses the external thread, either to protect the thread or to protect nearby objects from contact with the thread. In addition, the dome gives a more finished appearance.

Acorn nuts are usually made of brass, steel, stainless steel (low carbon content) or nylon. They can also be chrome plated and given a mirror finish

14. Flange Nut

A flange nut is a nut that has a wide flange at one end that acts as an integrated washer. This serves to distribute the pressure of the nut over the part being secured, reducing the chance of damage to the part and making it less likely to loosen as a result of an uneven fastening surface.

15. Lug Nut

A lug nut is a nut fastener with one rounded or conical (tapered) end, used on steel and most aluminum wheels. A set of lug nuts is typically used to secure a wheel to threaded wheel studs and thereby to a vehicle's axles.

The conical lug's taper is normally 60 degrees (although 45 degrees is common for wheels designed for racing applications), and is designed to center the wheel accurately on the axle, and to reduce the tendency for the nut to loosen, due to fretting induced precession, as the car is driven. One popular alternative to the conical lug seating design is the rounded, hemi-spherical, or ball seat.