NITTO KOHKI Japan make TCT and HSS cutters are available from 12mm dia upto 100mm dia and in lengths from 25mm to 75mm. These cutters are made completely in Japan. They provide the best efficiency and value for money in terms of cost per hole.
Broach Annular Cutters
An annular cutter (also called as core drill, core cutter, broach cutter, trepanning drill, hole saw, or cup-type cutter) is form of core drill used to create holes in metal. An annular cutter cuts only a groove at the periphery of the hole and leaves a solid core or slug at the center.
An annular cutter is a more expensive and more efficient alternative to spiral drill bits and standard hole saws. An annular cutter is similar to a hole saw but differs in geometry and material. The two most common types are Hi-Broach Cutters (HSS) and Jet Broach Cutters (TCT).
Like a hole saw, but unlike a spiral drill bit, an annular cutter cuts only the periphery of a hole, leaving a circular “slug” at the center.
Annular cutters are available from 12 mm (1/2’’) diameter to 200 mm (7 7/8’’) and larger. Depths of 30 mm, 55 mm, 75 and 110 mm are commonly available.
Annular cutters are best used with a drill press or magnetic drilling machine, both for their stability against high torque forces created by such a drill bit and lower RPMs compared to other types of drills.
Why are Broach Cutters so efficient?
As broach cutter cuts only on the periphery of the hole to be made, it has to remove much less material as compared to conventional drill bits which cut and remove the complete material of the hole. Annular cutters are considered to be 3 to 4 times faster than conventional drill bits. Also while using a twist drill bit or metal hole saw one has to do pre-drilling and step-drilling operations for bigger diameter holes, whereas an annular cutter requires no pre-drilling and step-drilling. It is a one-shot drilling operation.
The annular cutters have fewer teeth and less wear, therefore with an annular cutter holes can be made at higher or faster cutting speed and a faster feed rate of the drilling machine.
NITTO KOHKI HI-BROACH HSS CUTTERS
HSS core drills are made from high-speed steel material. These are most popular core drills or annular cutters in market. HSS core drills are cheaper for smaller diameter i.e. 40 mm. The biggest advantage of HSS core drill is its ability to re-sharpen. Unlike TCT core drills, HSS core drills re-sharpened and used with good efficiency until the desirable length is remaining. HSS core drills have longer service life, high heat resistance: the characteristics of HSS core drills is that drilling with these core drills can be done without the use of excessive force.
NITTO KOHKI JET-BROACH TCT CUTTERS
Tungsten carbide-tipped (TCT) drills have tungsten carbide embedded in their tip, a material that can cut faster and more efficiently through tougher materials. TCT drills are more expensive than high speed steel (HSS) drills, but are cheaper than cobalt drills for larger sizes – above 41mm.
NITTO KOHKI TCT cutters are best used with NITTO Magnetic Drilling Machines.
Some of the features of NITTO TCT cutters are :-
- Carbide tips for faster cutting
- Single pass cutting, no pilot hole required
- Annular part does all the work so small cutting resistance reduces drilling time
- Cutting of slanted, elongated and edge holes is now possible
- Fractional and metric cutter sizes to suit wide range of applications
- Produces little slag and few chips for easy disposal
- Can also be fitted to and used with previous Atra Ace models using a hexagon socket set-screw
- Improved concentricity extends cutter life! One-touch system consisting of three balls inside the arbor body produces a self-centering effect during cutting to improve cutter performance and life