Welcome to the World of Quality Bolts Manufacturers from India!

This is Nuts Bolts Washers India, a world of Bolts in itself, fully Integrated company exclusively engaged in manufacturing and exporting quality Hot Forged Bolts from more than a decade. This is not just a fastening firm but also a one door arrangement for all your requirements for Threaded Bars, Bolts, Nuts and Washers.

The words bolt and screw have both existed since before today's modern mix of fastener types existed, and the natural usage of those words has evolved extraneously in response to the technological change. (That is, the use of words as names for objects changes as the objects themselves change.) Non threaded fasteners predominated in fastening technology until the advent of practical, inexpensive screw-cutting in the early 19th century. The basic meaning of the word screw has long involved the idea of a helical screw thread.

The word bolt is also a very old word, and it was used for centuries to refer to metal rods that passed through the substrate to be fastened on the other side, often via non threaded means (clinching, forge welding, pinning, wedging, etc). The connection of this sense to the sense of a door bolt is apparent. In the 19th century, bolts fastened via screw threads were often called screw bolts in contradistinction to clench bolts.

A bolt is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder, or shaft. Sometimes the screw thread mates with a complementary thread, known as an internal thread, often in the form of a nut or a object that has the internal thread formed into it. Their most common use is to hold objects together or locate objects.

Oftentimes screws have a head, which is a specially formed section on one end of the screw that allows it to be turned, or driven. Common tools for driving screws include screwdrivers and wrench's. The head is usually larger than the body of the screw, which keeps the screw from being driven deeper than the length of the shaft and to provide a bearing surface. There are exceptions; for instance, carriage bolts have a domed head that is not designed to be driven; set screws do not have a head larger than the shaft; and J-bolts don't have a head and aren't designed to be driven.

The majority of screws are tightened by clockwise rotation, which is termed a right-hand thread. Screws with left-hand threads are used in exceptional cases, when the screw is subject to anticlockwise forces that might undo a right-hand thread.

Our Specialty

“We are specialized in manufacturing and exporting special grade Hot Forged Bolts like Super Duplex Steel, Duplex Steel, Hastelloy, Monel, Inconel, Alloy20 etc.”

Bolts

“We are manufacturer and exporters of Hot Forged Bolts and we have expertise in manufacturing ASTM A193 Grade Bolts.”

An example of an ordered list for Bolts:

ASTM A193 Grade B8M Bolts.
ASTM A193 Grade B8 Bolts.
ASTM A193 Grade B8T Bolts.
ASTM A193 Grade 8C Bolts

Differentiation between bolt and screw A carriage bolt with square nut

A bolt is an externally threaded fastener designed for insertion through holes in assembled parts, and is normally intended to be tightened or released by torquing a nut while a screw is an externally threaded fastener capable of being inserted into holes in assembled parts, of mating with a preformed internal thread or forming its own thread, and of being tightened or released by torquing the head. An externally threaded fastener which is prevented from being turned during assembly and which can be tightened or released only by torquing a nut is a bolt. (Example: round head bolts, track bolts, plow bolts.) An externally threaded fastener that has thread form which prohibits assembly with a nut having a straight thread of multiple pitch length is a screw. (Example: wood screws, tapping screws.)

This distinction is consistent with ASME B18.2.1 and some dictionary definitions for screw and bolt.

The issue of what is a screw and what is a bolt is not completely resolved with Machinery's Handbook distinction, however, because of confounding terms, the ambiguous nature of some parts of the distinction and usage variations. Some of these issues are discussed below:

Hex bolt

At times the term is used interchangeably with hex cap screw. An ASME B18.2.1 compliant hex bolt is built to different tolerances than a hex cap screw.

Hex Head Machine screws

ASME standards specify a variety of “Machine Screws” in diameters ranging up to 3/4 of an inch. These fasteners are often used with nuts and they are often driven into tapped holes. They might be considered a screw or a bolt based on the Machinery's Handbook distinction. In practice, they tend to be mostly available in smaller sizes and the smaller sizes are referred to as screws or less ambiguously as machine screws, although some kinds of machine screws can be referred to as stove bolts.

Hex cap screws

ASME standard B18.2.1 -1981 specifies Hex Cap Screws that range in size from 1/4 to 3 inches in diameter. These fasteners are very similar to hex bolts. They differ mostly in that they are manufactured to tighter tolerances than the corresponding bolts. The Machinery's Handbook refers parenthetically to these fasteners as “Finished Hex Bolts”.[8] Reasonably, these fasteners might be referred to as bolts but based on the US government document, Distinguishing Bolts from Screws, the US government might classify them as screws because of the tighter tolerance.

Lug bolts & head bolts

These terms refer to fasteners that are designed to be threaded into a tapped hole that is in part of the assembly and so based on the Machinery's Handbook distinction they would be screws. Here common terms are at variance with Machinery's Handbook distinction. This variance, perhaps, originated from common usage ideas that screws are small and bolts are big.

Lag bolt

These are clearly screws based on the Machinery's Handbook distinction. The term has been replaced by "Lag Screw" in the Machinery's Handbook[12] and probably only continues in common usage because of common language notion that bolts are big.
Government standards

U Bolts

U Bolts are being made of Threaded Rod having proportioately equal threads on each size in U form...................>>>>>>>>>>>>>

Bolts have been defined as headed fasteners having external threads that meet an exacting, uniform bolt thread specification (such as M, MJ, UN, UNR, and UNJ) such that they can accept a non tapered nut. Screws are then defined as headed, externally-threaded fasteners that do not meet the above definition of bolts.

In common usage, the distinctions are that screws are generally smaller than bolts, and that screws are generally tapered and bolts are not. These distinctions are not rigorous. The problem in definitions arises because both bolt and screw were older words in wide use. The bolt that locks doors and the bolt fired by crossbows and the screw of Archimedes and the screw gimlet (like a corkscrew) preceded the fasteners of the same names.

Types of screws and bolts

Threaded fasteners either have a tapered shaft or a non-tapered shaft. Fasteners with tapered shafts are designed to either be driven into a substrate directly or into a pilot hole in a substrate. Mating threads are formed in the substrate as these fasteners are driven in. Fasteners with a non-tapered shaft are designed to mate with a nut or to be driven into a tapped hole.

Coach screw

Coach Screws are being having very sharp point for self drilling but they can not be self tapping screws. These Coach Screws may have Hex Head or Square Head as per customer requirement. Coach Screws are being generally used at wooden walls since it have a very sharp point to be gripped with the wall.

Lag screw (lag bolt)

Similar to a wood screw except that it is generally much larger running to lengths up to 15 inches (381 mm) with diameters from ¼" to ½" (6.4–12.25 mm) in commonly available (hardware store) sizes (not counting larger mining and civil engineering lags and lag bolts) and it generally has a hexagonal head drive head. Lag bolts are designed for securely fastening heavy timbers (post and beams, timber railway trestles and bridges) to one another, or to fasten wood to masonry or concrete.
Lag bolts are usually used with an expanding insert called a lag in masonry or concrete walls, the lag manufactured with a hard metal jacket that bites into the sides of the drilled hole, and the inner metal in the lag being a softer alloy of lead, or zinc amalgamated with soft iron. The coarse thread of a lag bolt and lag mesh and deform slightly making a secure near water tight

Double ended screw (dowel screw)

Similar to a wood screw but with two pointed ends and no head, used for making hidden joints between two pieces of wood.

Screw eye (eye screw)

Screw with a looped head. Larger ones are sometimes call lag eye screws. Designed to be used as attachment point, particularly for something that is hung from it.

Breakaway Bolt

A Bolt with a hollow threaded shaft. Designed to break away when impacted. Typically used to fasten fire hydrants, so they will break away when hit by a car. Also used in aircraft, not to break away, but to make them lighter in weight.

Cap screw

In places the term is used interchangeably with bolt. In the past the term cap screw was restricted to threaded fasteners with a shaft that is threaded all the way to the head, but this is now a non-standard usage.

Hex cap screw

Cap screw with a hexagonal head, designed to be driven by a wrench (spanner). An ASME B18.2.1 compliant cap screw has somewhat tighter tolerances than a hex bolt for the head height and the shaft length. The nature of the tolerance difference allows an ASME B18.2.1 hex cap screw to always fit where a hex bolt is installed but a hex bolt could be slightly too large to be used where a hex cap screw is designed in.

Socket cap screw

Also known as a socket head cap screw, socket screw or Allen bolt, this is a type of cap screw with a hexagonal recessed drive. The most common types in use have a cylindrical head whose diameter is nominally 1.5 times (1960 series design) that of the screw shank (major) diameter. Counter bored holes in parts allow the screw head to be flush with the surface or recessed. Other head designs include button head and flat head, the latter designed to be seated into countersunk holes. A hex key (sometimes referred to as an Allen wrench or Allen key) or hex driver is required to tighten or loosen a socket screw. Socket screws are commonly used in assemblies that do not provide sufficient clearance for a conventional wrench or socket.

Machine screw

Generally a smaller fastener (less than 1/4 inch in diameter) threaded the entire length of its shaft that usually has a recessed drive type (slotted, Phillips, etc.). Machine screws are also made with socket heads (see above), in which case they may be referred to as socket head machine screws.

Self-tapping machine screw

Similar to a machine screw except the lower part of the shaft is designed to cut threads as the screw is driven into an untapped hole. The advantage of this screw type over a self-tapping screw is that, if the screw is reinstalled, new threads are not cut as the screw is driven.

Set screw (grub screw)

Generally a headless screw but can be any screw used to fix a rotating part to a shaft. The set screw is driven through a threaded hole in the rotating part until it is tight against the shaft. The most often used type is the socket set screw, which is tightened or loosened with a hex key.

Tap bolt

A bolt that is threaded all the way to the head. An ASME B18.2.1 compliant tap bolt has the same tolerances as an ASME B18.2.1 compliant hex cap screw.

Eye bolt

A bolt with a looped head.

Toggle bolt

A bolt with a special nut known as a wing. It is designed to be used where there is no access to side of the material where the nut is located. Usually the wing is spring loaded and expands after being inserted into the hole.

Carriage bolt (coach bolt)

Has a domed or countersunk head, and the shaft is topped by a short square section under the head. The square section grips into the part being fixed (typically wood), preventing the bolt from turning when the nut is tightened. A rib neck carriage bolt has several longitudinal ribs instead of the square section, to grip into a metal part being fixed.

Stove bolt

A type of machine screw that has a round or flat head and is threaded to the head. They are usually made of low grade steel, have a slot or Philips drive, and are used to join sheet metal parts using a hex or square nut.[16]
Shoulder screw
Screw used for revolving joints in mechanisms and linkages. A shoulder screw consists of the shaft, which is ground to a precise diameter, and a threaded end, which is smaller in diameter than the shaft. Unlike other threaded fasteners, the size of a shoulder screw is defined by the shaft diameter, not the thread diameter. Shoulder screws are also called stripper bolts, as they are often used as guides for the stripper plate(s) in a die set.

Thumb screw

A threaded fastener designed to be twisted into a tapped hole by hand without the use of tools.

Tension control bolt (TC bolt)

Heavy duty bolt used in steel frame construction. The head is usually domed and is not designed to be driven. The end of the shaft has a spline on it which is engaged by a special power wrench which prevents the bolt from turning while the nut is tightened. When the appropriate torque is reached the spline shears off.

Plow bolt

A bolt similar to a carriage bolt, except the head is flat or concave. There are many variations, with some not using a square base, but rather a key, a locking slot, or other means. The recess in the mating part must be designed to accept the particular plow bolt.

Thread rolling screws

These have a lobed (usually triangular) cross section. They form threads by pushing outward during installation. They may have tapping threads or machine threads.
Super bolt, or multi-jack bolt tensioner

Alternative type of fastener that retrofits or replaces existing nuts, bolts, or studs. Tension in the bolt is developed by torquing individual jack bolts, which are threaded through the body of the nut and push against a hardened washer. Because of this, the amount of torque required to achieve a given preloads is reduced. Installation and removal of any size tensioner is achieved with hand tools, which can be advantageous when dealing with large diameter bolting applications.

Other historical, specialized Threads on Threaded Bar systems include:

* Acme thread form
* BSC (British Standard Cycle) a 26tpi thread form
* British Standard Buttress Threads (BS 1657:1950),
* British Standard for Spark Plugs BS 45:1972
* CEI (Cycle Engineers Institute, used on bicycles in Britain and possibly elsewhere)
* British Standard Brass a fixed pitch 26tpi thread
* Edison base lamp holder screw thread
* Fire hose connection (NFPA standard 194)
* Hose Coupling Screw Threads (ANSI B2.4-1966) for garden hoses and accessories
* Lowenhertz thread, a German metric thread used for measuring instruments
* NPT (National Pipe Thread) and NPTF (National Pipe Thread Fuel)
* PG (German: "Panzer-Gewinde"), used in thin plate metal, such as for switches and nipples in electrical equipment housings
* Society Thread, a 36 threads/inch Whit worth form standarded by the Royal Microscopical Society of London for microscope objective lenses.