Technical | JR Carbide Burrs

Burr Cuts

The burr cut is the head or fluting pattern which describes the arrangement of the cutting teeth on a carbide burr, and each cut produces a different chip. The most popular cut is Double cut as it is versatile and can be used for most applications. Softer metals such as aluminium or zinc should not use double cut because the teeth become loaded. The Non-ferrous cut solves this issue with a deeper flute structure.

	Double cut is the most popular as it allows rapid stock removal on harder materials. The chisel tooth pattern minimises tool chatter and helps to eliminate loading the flutes. Excellent tool control is realised because of a reduced pulling action.
	Non-Ferrous cut allows extremely fast stock removal of softer materials such as aluminium and zinc. The deep flute structure helps to eliminate burr loading.
	Single cut or standard cut can be used on a diverse alloy range like double cut however it is better on relatively harder alloys which will not load the flutes. It has a smooth finish and produces sharp slither chips.

In our part codes the letter D refers to Double Cut and the letter N refers to Non-Ferrous. For example CE-3D is double cut and BA-3N is non-ferrous cut.

Burr Styles

Burr Style	Part Code	Usage
Ball Burrs	BA
Cone Burrs	CO
Cylinder End Cut Burrs	CE
Cylinder Flat End Burrs	CF
Cylinder Radius Burrs	CR
Flame Burrs	FL
Inverse Cone Burrs	IC
Oval Burrs	OV
Tree Radius Burrs	TR

Burr Sizes

Using carbide burrs with bent wrists increases the likelihood of carpal tunnel syndrome. The length of time and the forces the wrist is subjected to compound the chance of injury. Experienced users often move the whole arm in a smooth motion and do not apply too much force. Think of the die grinder as part of your arm.

Measurement	Description	Diagram
D1 (mm)	Diameter of the burr head
L2 (mm)	Length of the burr head
D2 (in)	Diameter of the burr shank
L1 (mm)	Length of the burr
Angle	Angle of the burr head

Burr Usage

Keep the burr moving

Beginners often mistakingly push the burr directly on to the metal surface which digs in and then spins out scoring a line in the metal. It is best to keep a smooth controlled action back and forth and if possible finish on an up stroke resulting in a better finish.

Maintain straight wrists

Experienced burr operators move the whole arm in a smooth motion. This makes it easier to keep the burr at the correct angle and pressure on the grinding surface. Think of the die grinder as an extension of your arm. The added benefit is that this reduces the chance of injury.

Avoid excessive pressure

Applying excessive force will blunt your burrs prematurely, Michael the same as using a drill bit. Apply just enough pressure to allow the burr to do the work.

Use the correct cut, shape and size

Choosing the carbide burr with the correct size, shape and cut is critical for quality and productivity. The incorrect burr for the job can make completing the job difficult or impossible. Each burr shape is suitable for a different function so choose wisely. It can be beneficial to have a carbide burr set or a range of carbide burr bits in your toolbox. Aluminium and other soft metals require a non-ferrous cut burr for working at optimal speed.

Use the correct speed

The diagram below shows that the larger the diameter of the burr head, the slower RPM required of the die grinder. Extra long burrs with 6mm shanks over 150mm long and 3mm shanks over 50mm long should be used at reduced speeds.

Speed Recommendations

Injury Prevention Tips

Maintain straight wrists

Avoid holding awkward positions

Otherwise known as static muscle loading. Holding your tool for extended periods of time at an awkward height or angle will create excessive fatigue. The tool should be used with the arm and shoulder in a natural position. The heavier the tool the quicker the fatigue. Using the correct size die grinder or Dremel suited to the task will reduce this risk.

Protect your eyes

Wear your safety glasses or full mask during all burring operations.

Protect your ears

Your brain adjusts to high volume noise so you can be unaware of the damage happening to your ears. Noise can result in permanent loss of hearing. Ear plugs or ear muffs should be worn in noisy environments.

Reduce repetition

Avoid repetition by switching between left and right hands or alternating tasks and swapping roles with other workers.

Avoid tools that concentrate stress on the hand

Pressure on the soft tissue of the hand can inhibit nerves and blood flow. A cheap tool that digs into your hand is not suitable for prolonged periods of use. Choose more ergonomic tools for larger projects. Well designed tools required very little hand force.

Use less force

Experienced deburrers do not apply much force. A smoother action gives a better finish and greatly increases the life of the carbide burr. This optimal method is also less fatiguing for the user.

Accidental injury

Respect the danger of the tool. Too often avoidable injuries occur, such as die grinder that is still running being dropped onto a worker’s leg or arm causing the carbide burr bit to remove the skin, or a person checking the temperature of a carbide burr with their fingers resulting in burns.

What are carbide burrs?

Carbide burrs, also known as rotary burrs, are a small cutting tool used to cut, grind or smooth metal. They are used extensively in workshops throughout the world. The carbide burr is characterised by a cylindrical shank with a cutting head. There are numerous head shapes and sizes designed for different applications. The head has many small cutting teeth which gives the burr a smooth finishing action. The teeth pattern is called the cut or fluting pattern. Different cuts are suited to different materials or applications.

What can carbide burrs be used on?

Carbide burrs are predominately used on metals, but are able to be used on all sorts of materials. Metals such as steel, carbon steel, cast steel, stainless steel, aluminium, brass, copper, zinc, bronze, titanium, nickel, cobalt, cast iron, gold and silver can be cut using carbide burrs. The softer metals use a different cut (head pattern) on the burr. This cut is usually referred to as non-ferrous or aluminium cut. Soft alloys include aluminium, brass, copper, zinc and gold. Other industries use burrs on materials such as plastics, wood, teeth, fibreglass and acrylic.

What are carbide burrs made of?

The two main material types of burrs are Tungsten Carbide and HSS (High Speed Steel) . Carbide is harder than HSS, and is the preferred choice in many industries because they last longer. They also handle higher temperatures than HSS allowing faster metal cutting. HSS is not suited to hard alloys but is easier to sharpen than carbide. Less common materials include tungsten vanadium and titanium-nitride coated burrs.

What is a carbide burr shank?

The shank is the shaft of the carbide burr. When referring to the shank size as 1/4″ or 6mm, this is the diameter of the shank. It is important to match the shank size with the tool you intend to use. The engineering standard shank size in Australia for carbide burrs is a 1/4″ shank. In the dental industry it is smaller. Long shank carbide burrs refer to extra long shafts. The standard length of an industrial burr is around 50mm.

Who uses carbide burrs?

There are many industries and individuals who use carbide burrs. Traditionally they are used in welding, foundries, engineering, and dentistry.

What are the two meanings for the word burr?

One meaning is the small cutting tool and the other refers to the sharp imperfections created by the machining process. Machinists need to deburr machined parts in order to remove these problematic burrs.

What is deburring?

A common problem in manufacturing is the removal of machining burrs. These burrs are imperfections caused by the machining process and cost the industry billions of dollars every year. There are four main types of burrs. The poison burr, The roll-over burr, The tear burr and the cut-off burr. These burrs can jam precision assemblies, impede the part function and injure staff. Deburring is the removal of burrs from parts. Machinists have a number of tools other than carbide burrs to remove machining burrs such as knives, files, reamers, and chamfering tools.