Broaching is a precise machining process in metalworking domain which uses a toothed tool called broach to cut materials into a predetermined shape. Broaching works best for odd shapes where precision machining is needed and hence finds wide application in a number of industry in India and worldwide. Broach resembles a saw to certain extent but unlike a saw, its teeth become larger in size across its length. A broach gives shapes by roughing or removing the material, semi finishing and then by imparting the ultimate finishing. Round or odd shapes, for both internal and external surfaces, can be conveniently formed by broaching. This multi edge tool can shape any metal or metallic alloy but works best on softer materials like plastic, wood, bronze, aluminum, etc. Resharpening of the tool The broach that imparts shape to many work pieces can work properly only when the size and shape of its teeth are perfect. With time and usage, the teeth tend to lose its sharpness and become blunt. Using a dull broach may lead to permanent damage of its teeth. To enhance the broach life and minimize the tooling expense, it needs to be re-sharpened on time. When to opt for resharpeningWhen broaching produce roughly shaped work pieces, it is definitely time for re-sharpening. However, with a little bit of watchfulness, one can even get it sharpened before it delivers poor finish or tearing. Some of the other conditions when this toothed tool will require re-sharpening are:• Excessive hydraulic press pressure required to run the broach• Nicks and scratches on the teeth making it dull • Broach starts drifting• Cutting edges show signs of wear • Chattering occurs while broaching Re-sharpening requires high precision. Removing excessive material from the teeth will adversely affect its longevity. Only proper sharpening will ensure time efficiency and high quality output. Teeth welding, grinding of gullets and teeth crest, reshaping teeth to proper taper are some of the methods used in re-sharpening.Broaching, once used for machining only internal keyways, is now used for machining a plethora of shapes and surfaces for high quantity of work pieces. Broaching requires less tools than most of the other machining process and saves considerable amount of output time and hence favoured for high volume production irrespective of its high cost. In India, broaching finds wide application in the automobile industry. Therefore, a large number of players are foraying into the broach manufacturing industry on a regular basis.

~ Ankur Sood