Fastener may be defined as any device, method or component used to hold or FASTEN two or more engineering components together. Fasteners may be classified into groups and sub-groups according to the functions they perform. Probably the main division is into:
a. Detachable fasteners (e.g. nut and bolt, screw, etc.);
b. Non-detachable fasteners (e.g. rivet, weld, adhesive).
Fastener Material can be important when choosing a fastener due to keeping in view the strength, brittleness, corrosion resistance, galvanic corrosion properties. Cost of course an important factor which determines which materials to choose from.
A screw is a broad category of mechanical fastener with a threaded shaft, designed to screw into a part. This includes wood screws and self-tapping screws, which have a tapered shaft with sharp threads designed to cut a mating thread in the part to which they are fastened. It also includes machine screws, which much more closely resemble bolts, but their entire shaft is normally threaded.
Nuts and Bolts are most commonly used items in the family of industrial fasteners and their demand is fast increasing due to expansion of industries in the country. Bolt is a piece of metal rod whose one end is upset and at the other end threading is done. Nut is a device which rolls on bolt threads. In nuts, internal threading is done while bolts bear external thread. Screw, demonstrate their true merit in the movements, assembly etc, of wooden components. Screws are most popular as fasteners which assemble, or join parts together to be made into a complete unit.
Few Indian Major Players
1. Adinath Forging Pvt. Ltd.
2. Agarwal Bolts Ltd.
3. B G Fastening & Engg. Inds. Pvt. Ltd.
4. Deepak Fasteners Ltd.
5. G S Auto International Ltd.
6. Indian Fasteners Ltd.
7. J C Fasteners Ltd.
8. Lakshmi Precision Screws Ltd.
9. Mahalaxmi Fasteners Pvt. Ltd.