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About Us

Kiran Fasteners is a well-known and well-established firm that deals with industrial fastening solutions. Kiran Industries was established in the year 1989 in Rajkot, Gujarat, and has now become a reputed brand for being a responsible company with good benchmarks and precision-engineered products.

Contact Info
Sr. No. 211, Narmada Pipe Gate, Tal. Kotda Sangani, Plot No. 3, Essen Road, At, Shapar, Rajkot, Gujarat 360024, India
info@kiranindustries.in
Working Hours: 9:00 AM to 6:00 PM
Kiran Industries

Industrial Fasteners FAQs

Industrial fasteners such as bolts, nuts and threaded components are essential for construction, engineering and manufacturing industries. Buyers and engineers often have questions regarding materials, coatings, strength grades and applications of fasteners. This FAQ section provides answers to common questions about industrial fasteners to help businesses select the right fastening solutions for their projects.


Choose the bolt using three parameters: diameter, length, and thread pitch. It should fit into the hole the same size as the diameter of the hole, be long enough to allow full engagement of the nut (at least 2 or 3 threads sticking out after tightening), and the thread pitch of the tapped hole should match the nut or the hole to be tapped. In structural or machinery work, the equipment or drawing requirements should always be adhered to.

Grade 2 bolts are normally sufficient in the case of light household or general fixtures. Grade 5 is usually used in assemblies in the automotive, mechanical, and load-bearing sectors, whereas Grade 8 or high-tensile bolts should be used on high-tension components like industrial machines, suspension, or structural joints.

Bolts are removable and reusable unless stretched, corroded, or damaged. If the shank shows necking due to thread wear, or a bolt has been used in a demanding high-torque or safety service (e.g., engine or structural connections), replace it.

The loosening of bolts is primarily caused by vibration, thermal expansion, or inadequate tightening force. Such prevention measures as torque straightening with a torque wrench, lock nuts or spring washers, thread-locking compounds, and the selection of thread type and bolt grade to use under the load conditions might be provided.

Allen bolts are internally threaded, and thus they are tightened by an Allen key at the top rather than the sides. They offer reduced side clearance and high-torque transfer, and eliminate the possibility of spanner slippage and are therefore suited to small assemblies and exacting equipment.

Machinery and automotive layouts use Grade 12.9 Allen bolts, which are high-tensile alloy steel bolts, for heavy and structural loads. Stainless steel (SS304/SS316) Allen bolts have less tensile strength but superior corrosion resistance and can therefore be used in outdoor, marine, and chemical environments.

Yes, the Allen bolts may loosen under the vibratory load or dynamic load, as any other threaded fastener. To ensure that the thread remains tight, engineers usually apply thread-locking compounds (such as anaerobic adhesive), spring washers, Nyloc nuts, or torque-corrected tightening according to the manufacturer's instructions.

Choose by three parameters: thread diameter (e.g., M6, M8), length (measured under the head in the case of socket heads), and pitch (coarse or fine thread). The decision that is made will depend on load requirements, the thickness of the material used, and whether it is in accordance with standards like DIN 912, DIN 7380, or DIN 7991.

A flange bolt is also provided with a washer-shaped flange underneath the head, and it spreads the load exerted by the clamping uniformly over the surface. A typical hex bolt needs a second washer to obtain a comparable distribution of loads and surface coverage.

Vibration-prone assemblies (automotive parts, machinery frames, etc.) are preferred to use serrated flange bolts, as the teeth are able to hold onto the surface and inhibit loosening. If the mating surface is soft, coated, or requires no marking, then non-serrated flange bolts are applied.

The majority of metric flange bolts receive DIN 6921 specifications. They are regularly produced in zinc-plated alloy steel (Grade 5 or Grade 8) to provide strength and overall corrosion resistance and in stainless steel (304/316) to withstand weather, damp, or sea conditions.

Flange bolts do not need any extra washers. The tightening of the bolt has to be continued until the flange touches the surface, and the appropriate level of torque should be chosen based on the type of material of the bolt, its grade, and its size to provide a firm fix without causing any damage.

No. Brass bolts are not as tensile stress resistant and strong as steel bolts. Their selection is not at all as heavy as structural load-bearing; it depends upon the resistance to corrosion and the conductivity.

They are extensively used in electrical connections and grounding, plumbing fittings, marine hardware, decorative furnishings, and light machinery, where rust resistance and a decorative finish are needed.

A brass bolt resists rust, unlike iron or steel, because it lacks iron. Actually, it forms a low-protection coating, which is helpful in the fight against corrosion in wet coastal, external, and seawater environments.

Because of the relatively tender character of brass, more than normal tightening could strip the thread or punch the head of the bolt out of shape. It is advised that the right torque, the correct spanner/Allen key, and, in certain situations, a washer must be used to distribute the load evenly.

Copper bolts have an extremely high electrical conductivity, and thus, the flow of current can occur at minimum resistance. This renders them applicable for earthing systems, switchgear assemblies, busbars, and power distribution equipment.

Copper does not rust because it is not composed of iron. Rather, it develops a protective coating (patina) that covers the surface to inhibit further corrosion and is therefore resistant to the marine, outdoor and chemical conditions.

Copper bolts are not normally used at high mechanical loading. Unlike steel, they are not as hard and thus conductive; resistance to corrosion and non-magnetic behaviour, rather than structural strength, is the reason for their choice.

Be careful that it is not tightened too much because copper is ductile and the threads may break. Use the correct torque value, and use the correct washers and compatible nuts to prevent galling and have a secure and long-lasting joint.

A hex nut consists of a correspondingly threaded rod or bolt to hold two or more parts together. On tightening, it forms a compressive clamping force, which keeps parts firmly in place.

Its six-sided shape gives it many contact points of a wrench, which can easily be tightened and loosened with a regular spanner or socket, and provides it with excellent transfer of torque and grip.

The nut size should be the same as the thread size and the thread pitch of the bolt (e.g., an M8 bolt must have an M8 nut). Check the thread standard (metric or imperial) and ensure material compatibility for a proper fit and strength.

Lock nuts (nylock) are better suited for vibrating applications, such as vehicles or machinery, to prevent loosening, while flange nuts are used when load distribution is required and a washer is not needed.

A weld nut gives a metal surface a permanent threaded bearing point. It can be welded, and bolts can be attached and detached from it many times without damaging the base material.

Delicate sheet metal is usually incapable of supporting robust threads. A weld nut will provide more rigid, full-depth threads, greater load-carrying capacity, and no re-tapping or sloppy hardware.

Weld nuts are designed to be used with weldable metals, which include mild steel or stainless steel. They can only be fitted on weldable metal surfaces, such as mild steel or stainless steel.

Yes. In order not to have thread distortion, spatter, or warping, proper alignment and controlled weld current are significant. When welding, often a bolt or protective plug is inserted to safeguard the internal threads.

Most electrical, plumbing, decorative, and light mechanical applications make use of brass nuts because they are moderately strong. But where very high loads or structural use is required, steel or alloy steel nuts are normally a choice.

Yes. Brass is very rust- and corrosion-resistant, so it can be used outdoors, in humid conditions, and in the sea. It works particularly well where water would easily corrode iron-based fasteners.

Absolutely. Brass is not magnetic and conducts electricity well, so brass nuts are used in electrical connections, terminals, and panels, especially for grounding, where excellent conductivity and reliability are important.

Copper nuts are commonly employed in earthing and grounding equipment, electrical panels, busbars, transformers, HVAC equipment, and marine installations where conductivity and corrosion resistance are crucial.

Yes. Copper is a powerful thermal conductor that can resist high temperatures compared to other coated fasteners; hence, copper nuts can be used in heat exchangers, electrical terminals, and other devices that are associated with furnaces.

Normal copper nuts have the tendency to loosen with vibration as the material is soft. For such applications, lock nuts, spring washers, or double-nut constructions should be used to ensure clamping force.

Maintenance is minimal. The electrical contacts should be provided with clean, unoxidized contact surfaces, and periodic checks to verify tightness will be performed to ensure that they have a long life of service.

Yes. Flange nuts are constructed to have a washer-like bottom base, which spreads the load evenly on the surface. This feature eliminates a separate washer in most applications, saving time required to install and allowing a reduction in the number of parts.

Serrated flange nuts can scratch or mark softer surfaces due to the teeth biting the material to be held in place. Plain flange nuts, or Nylock flange nuts, are a preferable option for visible surfaces or coated or delicate surfaces.

Absolutely. Serrated and Nylock flange nuts are made to stay tight even when they shake, making them ideal for use in cars, machines, and industrial equipment.

Finishes like zinc plating or galvanisation also enhance corrosion protection in extreme weather conditions.