Why Use An Annular Cutter?

An annular cutter is a specialized bit for drilling through steel. Like a hole saw for wood, an annular cutter only cuts the outside edge of a hole.

It produces accurate burr-free holes to close tolerances without pre-drilling or step drilling. It can drill a much larger hole and requires less force and time than a standard twist drill bit. As it turns, the cutter produces chips from the outside cutting edges and after cutting the hole a ‘slug’ (round chunk of steel from the center of the cutter) falls out.

Why use an annular cutter?

Annular Cutters offer superior holemaking capabilities. They cut faster, last longer, produce a better hole finish, a true round hole with very tight tolerances, can be re-sharpened and drills holes with less power and torque.

 TCT Annular Cutters

What is diamter and depth?

When determining cutter size, they are measured by depth and diameter. If you look at an actual cutter the depth is actually longer than what it is rated, (a 1" cutter is really 1-1/4") because this ensures the tool can drill all the way through the hole and allows extra length for resharpening.

What causes dull or broken cutters?

The primary cause of broken or prematurely dull cutters is a feed rate that is too slow. Slow feed rates will reduce the life of your cutter. Using a firm, steady feed pressure throughout the cut will maximize performance and extend tool life. You want to hear the drill motor working & the cutter producing long stringy chips that are being pulled from the hole. Look for a bird’s nest around the cutter.

HSS Annular Cutters

Blue Chips = Big Problem

(Something obstructing the coolant system or you’re pushing too hard)

Make sure you have the correct cutter for the material. Stack-Cut for multiple layers.

The second reason why cutters break is movement of the drill or work piece. The cutter wall can easily be snapped if the drill and material is not held rigid.

Why does my slug stick?

Using lubricant or cutting fluid helps the slug to eject at the end of the cut. But when

slug ejection becomes unreliable or the steel resists cutting, it probably means the

cutter’s cutting edges are becoming dull. Re-sharpen or replace your cutter. Also make sure there are no chips inside your cutter which can hold up a slug. Also periodically

check your ejection springs to maintain proper spring life.

Why not use quick change cutters?

Quick change cutters are nice and convenient if you need to change sizes every hole or two. But using a mag drill with the two set screws to hold the cutter in place offers a couple of advantages:

• Holds the cutter more rigid and less opportunity for it to move and break

• Will give up to 2x the tool life

Is a carbide cutter better than a HSS cutter?

Not necessarily. Carbide cutters are great tools and work good in most types of materials. But where they really shine is when they are used in hard or abrasive materials. They can be used in mild and structural steel but to get the best performance, carbide tooling needs to be turned at a much higher RPM than HSS cutters.