Needles are produced by

ANS:B - swaging

Swaging is a metal forming process used to shape or reduce the diameter of a metal component by using compressive forces. In swaging, the metal workpiece is forced into a die or around a mandrel to achieve the desired shape or size. This process can be performed at room temperature (cold swaging) or at elevated temperatures (hot swaging), depending on the material and desired outcome. Here's a breakdown of the swaging process:

1. Preparation: The metal workpiece, typically a rod, tube, or wire, is prepared for swaging. It may be cleaned, lubricated, and heated if necessary to facilitate the deformation process.
2. Placement: The workpiece is placed into the swaging machine, which consists of a die or set of dies and a mandrel.
3. Compression: The swaging machine exerts compressive forces on the workpiece, causing it to deform and take the shape of the die or mandrel. This compression can be achieved using hydraulic presses, mechanical presses, or other specialized equipment.
4. Shaping: As the workpiece is compressed, it flows around the contours of the die or mandrel, gradually taking on the desired shape. Swaging can be used to create various shapes, including cylindrical, tapered, stepped, or profiled forms.
5. Finishing: After swaging, the workpiece may undergo additional finishing operations such as cutting, grinding, or polishing to achieve the final dimensions and surface finish.

Swaging is commonly used in various industries for producing components such as tubes, shafts, bearings, fasteners, and medical instruments. It offers several advantages, including:

• Material Savings: Swaging can reduce material waste compared to machining processes since it involves reshaping the material rather than removing it.
• Increased Strength: Swaging can improve the mechanical properties of the workpiece by increasing its density and reducing porosity.
• Improved Dimensional Accuracy: Swaging can produce components with tight dimensional tolerances and precise geometries.

Overall, swaging is a versatile metal forming process that is widely used for shaping metal components with complex profiles and achieving high precision in manufacturing.