The introduction of carbide cutter inserts in metal working, definitely reduced the cost of machining and increased the productivity. The carbide cutters with inserts can produce work pieces similar to the ones which are produced using solid carbide cutters. But a carbide cutter insert is much inexpensive compared to solid carbide cutters. Example compared to a solid carbide end mill, a carbide insert milling cutter is cheaper. In case of carbide cutter insert it is much easy and less time consuming to replace the insert with another carbide cutter insert when the cutting edges are blunt and thus increase in productivity.
Types of Carbide Cutter Insert
Carbide cutter inserts are used in a variety of metal cutting operations. The application of carbide cutter inserts in turning tools and milling cutters are the most common ones. Carbide inserts are also used in drilling and in special cutters used in machining centers etc. Since we are discussing about metal cutting operations, I must also mention that carbide inserts are widely used Tool & Die industry especially for stamping dies manufacturing.
Depending on the design we can broadly classify these cutters as, brazed carbide insert tools and indexable carbide cutters.
Brazed Carbide Inserts
These are tools were the carbide inserts are brazed on to a steel tool holder. Brazing is a high temperature process by which the brazing alloy along with flux is melted and allowed to solidify to form a joint between steel and carbide insert. These type of cutting tools are mainly used for drilling and turning.
Pros: Brazed carbide tips are often stronger. They can withstand higher cutting force. Another advantage is that they can be used on smaller sized tools. For example masonry drill bits with carbide tips are brazed and then machined to size.
Cons: The number one disadvantage of brazed carbide tool is it’s inability to replace cutting tips. Removing the damaged cutting tip is a time consuming process. Also, when you replace with a new tool, you will often lose the tool setting time on the machine.
Indexable Carbide Cutters
Here the carbide inserts are fastened to the tool holder with screws. Compared to the brazed tools, it is very easy to replace the cutting tips in an indexable carbide cutter. The tool holder is generally made out of hardened steel and the insert seating area is machined accurately.
Pros: First of all, indexable carbide insert cutters are cost effective. You buy the tool holder once and replace the cutter insert. Often you can reverse the cutting insert, thus doubling the life of the carbide insert. Moreover you will save the setting time since in most cases you don’t have to reset the tool on the machine.
Cons: The major disadvantage is that replaceable insert design is not often possible for smaller sized tools. In such cases solid end mills or even brazed carbide insert tools are the way to go.