DIN/ISO/ANSI/JIS What are they?

DIN – Deutsches Institut für Normung (German Institute for Standards)

The vast majority of metric fasteners are presently manufactured to this standard which was created long before ISO standards. There are DIN standards for just about everything. DIN standards are currently being revised to more closely match ISO standards. For ordering fasteners all you need is

  • The DIN( which defines the style of the fastener)
  • The material desired (i.e. 8.8 Steel, 316 Stainless, Hastelloy C276)
  • The coating or plating (if any)

ISO – International Standard Organization

Founded in 1946 this organization publishes standards which individual countries have to vote on and are asked to apply. Currently ISO is comprised of more than 90 member countries. ISO’s standards for metric fasteners are rapidly gaining more recognition and in the years to come will probably become the world standard.

ANSI – American National Standard Institute

A US organization that has developed standards which are essentially in agreement with ISO standards.

JIS – Japanese Industrial Standard

Although mainly based on DIN, some standards have been modified based on the needs of the Japanese market. Fasteners used in most electronic equipment manufactured in Japan fall under the JIS standard.

All of the standards listed above detail an items’ dimensional specifications and material content. These standards are accepted worldwide and ensure you that any items that are ordered according to a particular standard will meet the specifications in compliance to the listed standards regardless of the manufacturer. Although there are many different standards for metric they are all manufactured to the same thread. The DIN spec may call for a certain head dimension and ANSI spec another but a 10×1.25 ANSI hex bolt will always thread into a DIN 10×1.25 hex nut and vice versa.

Top Stainless Steel Fasteners Manufacturers In India


We are Largest manufacturer, Exporters & Suppliers Of Stainless Steel Fasteners In India and have a large range ready stock of Stainless Steel fasteners Grades AISI 304, AISI 316, AISI 202, (AISI 310, Duplex, Super Duplex, Hastelloy Against order). 

Hex Bolts, Hex Nuts, Flange Nut, Wing Nut, Nylock Nut, Flange Nylock Nut, Flat (Plain) Washers, Spring Washers, Socket Head Cap Screw (Allen Cap, Allen Bolt) Anchor Bolt, Eye Bolt, Carriage Bolt, Flange Head Bolt, U bolts, Lock nut, Machine Screws, Self drilling screw, Self tapping Screw, Security Fasteners, Coach screw, Button Head, Grub Screws.

CHS, Phillips PAN, CSK,  Dome Nut, Square and Long Nuts. Rivet Nuts, Blind Nuts, Pop Rivets, Solid Rivets, Nails, Screws. Disc Washers, Multi tooth Washers, Dowel Pins Spring Dowel-pins, Thread Inserts, Security Screws etc. These are all available As Per DIN, ISO, ASME National And International Standard Fasteners Also Available.

What is corrosion?

Corrosion is the breakdown of a material due to contact with either a corrosive chemical or another material it reacts with. The latter is known as galvanic corrosion.

Is There a Difference Between a Bolt and a Screw?

Yes, there is. And, the best way to describe the difference is by understanding that you use screws with tapped holes and bolts with nuts.

Additionally, a screw is a tapered fastener that bonds with an existing thread or creates its own thread in a material as it rotates. On the other hand, bolts are non-tapered fasteners that require washers and nuts to hold objects together.

Most Stainless Steel Fasteners I Have Seen Have Marks on The Head. What Are These?

There are two types of marks on a bolt:

  • The first is the manufacturer’s or importer’s mark, which is a symbol identifying the manufacturer, and
  • The second is the grade mark (like: A2, A2-70,A2-80, A2-50, A4-70, A4-80, A4, B8M, B8, B7M, B7) which is a standardized mark that identifies the material properties that the fastener meets.

Do The Fine Threaded Fasteners Have Any Unique Benefits Over The Coarse Threaded Fasteners?

Yes, they do and these benefits include:

  • Less tendency to loosen,
  • Finer adjustments due to their smaller pitch,
  • More strength size for size compared to a coarse thread,
  • Easier to tap into hard materials and thin-walled tubes, and
  • They require less torque to develop equivalent bolt preloads.

Why is Stainless Steel Used for Fasteners?

  • Resistance to corrosion: Stainless steel doesn’t rust, meaning that the product will last longer and corrosion won’t affect the magnetic properties of the metal.
  • Low maintenance: Stainless steel is easy to clean and since it’s resistant to corrosion and rust, it’ll consistently have a flawless look on its own.
  • Value: Stainless steel fasteners are quite expensive, but they are definitely worth the money since they can last for over 50 years.
  • Strength: Stainless steel is incredibly durable and can withstand harsh weather conditions and corrosive environments.



FASTENERS General information

What is anti seize?

Anti-seize is a lubricant designed to limit the friction on fasteners during installation and reduce the chance of thread galling.

What is threadlocker?

Threadlocker is a paste that is applied to fastener threading before installation. Once installed the paste cures and holds the threads in place.

What is tolerance?

Tolerance is the accepted amount of variation from fastener to fastener that is allowed while still being considered the same size.

What is shear strength?

Shear strength is the amount of force a fastener can handle from its side without shearing.

What is tensile strength?

Tensile strength is the maximum load in tension a fastener can handle before or at breaking point.

What is tensile load?

Tensile load is maximum load that can be applied to a fastener before its breaking point. This force is tested by the installation materials pushing against the head and nut of the bolt.

What is elongation?

Elongation is the stretching of a fastener from head to tip which causes the bolt to warp. It is caused by too much torque applied to a bolt or too much pressure being applied.

What is torsional strength?

Torsional strength is the amount of torque a fastener can handle before it breaks.

What is yield strength?

Yield strength is the amount of force that can be applied to a fastener before it “yields” and begins to warp.

What is hardness?

Hardness refers to a materials ability to cause damage to another material without causing damage to itself. Example: It is possible to scratch your phone screen with your keys without damaging the keys. This is because your keys are harder than the glass screen.

What is fatigue strength?

When a fastener is exposed to multiple elements (heat, removal and reapplying pressure and other stress factors), a fastener will change shape and return to its original form. Fatigue strength refers to the maximum amount of stress it can handle for a number of cycles and still return to normal. Once a fastener exceeds its fatigue strength it is very likely to develop faults.

What is galling?

Galling is the fusion that occurs when metal is moving very fast against metal with friction and pressure. It causes the two pieces to weld together on the surface level which is known as galling. Stainless steel, aluminum, titanium and hot dip galvanized fasteners are all prone to galling.

How can I prevent galling?

Galling can be prevented by making sure an quality anti-seize lubrication is applied to the threads of a fastener prior to installation.

What is corrosion?

Corrosion is the breakdown of a material due to contact with either a corrosive chemical or another material it reacts with. The latter is known as galvanic corrosion.

What is galvanic corrosion?

Galvanic corrosion is the transfer of electrons from one material to the other which compromises the integrity of that material.

What is prevailing torque?

Prevailing torque is the measure pressure it takes to cause frictional resistance to rotation.

What is installation torque?

Installation torque is the highest torque needed to install a fastener before axial loading occurs.

What is breakaway torque?

The amount of torque required to start rotation between a fastener and its locking mechanism (such as a nut) when no axial load is present.

What is breakloose torque?

Breakloose torque is the initial amount of torque required to begin decompressing a fastener assembly

What is seating torque?

Seating torque is the torque that needs to be applied to create a compressive load under the head of the fastener.

What is an axial load?

An axail load is the amount of pulling or stretching force placed on the axis of rotation. One way to think of axial load is when attatching two pieces of wood together with a nut and bolt. Once the nut begins to firmly press against the wood, it begings to exert compression force. As the two pieces of wood struggle to maintain their original shape, force is exerted against the nut and bolt head by the wood. The force exerted against the nut and bolt are the axial load. This load can be increased by adding additional weight to the wood itself.

Are you ISO certified?

Yes. Kotadia INC. is ISO 9001:2008 certified (certificate number CA1617). As a distributor, we have always taken great care in purchasing to ensure that our vendors supply goods which conform to quality standards. Information on our quality system.