Washers

Instinox is the best-known brand worldwide in the manufacture and supply of valves and fasteners. We have a huge stock always readily available for immediate dispatch. We provide great delivery with the urgent dispatch for client emergency and other requirements. Our lead time is the lowest in the industry due to a ready stock of standard items with a bus. We have inventories for all sizes ranging from the smallest to the largest of fasteners.
At Instinox, we excel at executing both small size and bulk size orders. Our sales agent is in direct contact with you at all points right up to any point in future when you face any technical problem. Great emphasis is paid to value addition and after service.

A washer is a small thin plate that is disc shaped with a hole in the middle that is normally used to distribute the load of the threaded fasteners, such as a bolt or a screw or also a nut. Other uses are as a spacer, spring, wear the pad, preload indicating the device, locking device, and to reduce vibration. Washers usually have an outer diameter about the width of the torque is applied. Rubbers or filter gaskets that are used in tapes are usually used to stop the flow of water are sometimes referred to as colloquial washers.

Washers are also important for preventing galvanic corrosion, particularly by insulating steel screws from aluminium surfaces. Washers are made up of metal or plastic. High quality bolted joints require hardened steel washers to prevent the loss of preload due to permanent identification if hard surface after the torque is applied.

Raw material inspection & storage

Raw material for the bolt is to be decided by the designer based on its application. Material to be used is supposed to be inspected and then proper warehouse location is to be identified in order to avoid rust formation and proper coverage needs to be provided.

Unthreaded bolt manufacturing

Moreover casting and forging are used in this stage. Other methods may also be used for sintering and prototyping.

CNC machining

After the part has been manufactured through forging/casting method, it is then machined to the specific dimensions usually by CNC. The operations followed here are namely pointing, facing and grooving.

Heat Treatment

Heat treatment is done after machining is done to make the fasteners tensile strong. Hardening and tempering operations are then followed. Hardening is done such that bolt is heated to a temperature of 850-900 degree C and then quenched in the cooling media. Then the bolt is again reheated to bring back the complete hardened boltless soft so that the bolt remains strong enough. Re-heating is done to bring down the brittleness of the bolt which happened during hardening.

Surface finishing

The surface finishing process comes next. Usually, grinding process is carried out to make the surface smoother according to the surface finish specification.

Thread Rolling

After the finishing procedure, thread rolling is done with two dyes. One is stationary and another is a moving dye which actually exerts a force on the washers and forms threads. Threads on washers may be fine, medium or coarse depending upon the application of the bolt.

Coating

After thread rolling, bolt fasteners are coated in order to avoid rust and corrosion. A fine example of bolt coating is geomet coating in washers which is tested to Salt Spray Test, depending upon the number of hours as mentioned. Machinery is used to determine coating thickness along with other different measuring instruments such as coating thickness metre

• Plain washer – A flat ring of metal, used to spreads a load of a screwed fastening. A plain washer may be used when the hole is a larger diameter than fixing nut.
• Penny Washer – A flat washer with a large diameter in proportion to its central hole. They commonly used to load on thin sheet and are named after their use of automobile accessories.
• Spherical Washer – Self-aligning nut, it is a washer with a radiused surface, which is designed to be used in conjunction with a mating nut in order to correct for up to several degrees of misalignment between parts.
• Anchor plate or wall washer – it is a washer that is used to connect to a tie rod or bolt. Anchor plates are used on exterior walls of so many buildings for structural reinforcement.
• Torque washer – Used in woodworking in combination with a carriage bolt. It has a square hole in the centre into which the carriage bolt fits.
• Conical washer – A washer is a slightly conical shape which provides an axial force when deformed.
• Curved disc spring – Similar to conical washer except the washer is curved in only one direction, therefore, there are only four points of contact.
• Wave Washers – A washer with a wave in an axial direction, which provides spring pressure when compressed. Wave washers of comparable size do not produce as much force as conical washers. These are a less used and a less effective choice for use.
• Split washer – A ring split at one point and bent into helical share. This causes the washer to exert a spring force between the fasteners head and the substrate which maintains the washer hard against the substrate that creates more friction and resistance to rotation.
• Tab washer – a locking washer that works by having a side that can be bent into place against a nut is a tab washer.
• K-lock nuts – A nut with an integral free spinning washer, an assembly is an easier because the washer is captive.

Washers have a special design that attempts to help keep the nut and bolt from coming loose. It could be used under the bolt head instances when the bolts screws into threads in one part of the assembly.
A washer is sometimes used to protect the surface of the assembled parts. This may be particularly used when the parts are a softer material such as plastic or aluminium and a washer is made up of a harder material.

Washers help to keep the material flatter or to prevent pullout of the fastener.

Washers also help to prevent the turning of bolt head or nut deforming the slotted part during the tightening process.The washer must be designed to reduce the friction between itself and the moving part. This can help to keep turning part from trying to loosen the nut through friction

At Instinox, all fittings and flanges are subject to strict inspection and quality checks at all stages of the manufacturing process, from starting material purchasing to product dispatch. They are visually examined for conformity to ASTM, ASME, MSS, DIN, EN, and JIS codes and standards. At Our requests, officially certified agencies are called to witness the material reports, dimension and quality conformity of products.

Test Certificates are given to the manufacturer after third party inspection under the standards: EN 10204/3.1B, Raw materials Certificate, 100% Radiology Test report Test Certificate.