It is important to understand the relationship between tools and abrasives. We will cover common types of handheld tools as well as separate grinding and polishing machines. This section will also address common grinding problems associated with specific tools.

 

Operation

Cubic Feet Per Minute is a measure of how much air is required to run a air tool or series of air tools. The compressor must be able to generate enough air volume to keep the tool spinning at the correct RPM and horsepower requirements. This is a very common mistake by operators, as the PSI may be correct but after a few moments of operation the tool slows and horsepower becomes diminished. This is caused by the compressor failing to generate enough air for the tool. This will ultimately effect the performance of the abrasive as the SFPM is incorrect.

Pounds Per Square Inch is a measure of the force of the air itself. 90 is a common air pressure that is required by most air operated tools. Any more than 90 PSI usually causes seal and bearing problems with the tools. Any less usually causes a drop in RPM and horsepower of the tool.

Horsepower is a simple measurement of power. As mentioned above, the horsepower of an air tool is determined by the CFPM and PSI. Single phase electric tools have rather stable horsepower but will pull more amps under load that will cause overheating and lead to failure. Three phase tools have the ability to pull more amps in a small range without overheating and keep horsepower constant, even under a reasonable load.

 

Handheld Tools

Electric Tools are usually single phase, ranging from right angle to straight die and specialty grinders. Electric tools have a favorable weight to power ratio that can be used in the shop and on the job site. Some electric tools have variable speed features that allow speed adjustment at the same horsepower. This is a value in which multiple jobs are required. Electric tools have one major downfall - Most single phase motors are not sealed. This will allow dust and debris to enter the motor. Over time, this debris will collect on the coil of the motor and lead to failure due to overheating. Certain environments, such as foundries, generate large amounts of dust and debris and an unsealed electric motor would fail quickly because of this.

Electric	RPM		Horsepower		Accessories		Common Abrasives
Right Angle	10,000 5/8-11 Thread		1 to 1.5		Backing Pads Locking Nuts Wrenches		4-1/2, 5" RFD 4-1/2, 5" Flap Disc 5/8-11" Flap, Combination Wheels 4-1/2, 5" Type 27 Bonded Wheels 4-1/2, 5" Wire Brushes
	6,000 5/8-11 Thread		1.5 to 4		Backing Pads Locking Nuts Wrenches		7, 9" RFD 7, 9" Flap Disc 5/8-11" Flap, Combination Wheels 7, 9" Type 27 Bonded Wheels 7, 9" Wire Brushes
	2,000 to 5,000		1 to 2		Collets 1/8 to 1/2" Wrenches		Solid & Pneumatic drums for Coated Nonwoven Belts 4 to 8" Unmounted Flap Wheel Combination Wheels
Straight	10,000 to 20,000		1		Same		3" or Larger Mounted Flap/Combination Wheels 3" or Larger Square/Cross Pads Mounted Stones, Points and Burrs
	20,000 to 30,000		.5 to 1		Same		2" or Smaller Mounted Flap/Combination Wheels 2" or Smaller Square/Cross Pads No Lap Bands Cartridge Rolls Cone Points
Specialty	Belt/Dynafile 10,000		.5 to 1		Contact Arms and Wheels		Coated and Nonwoven Belts
	Drum 3,500		1 to 3		Solid and Pneumatic Drums		Coated and Nonwoven Belts Large 5/8-11" Flap and Combination Wheels

Pneumatic Tools are a well used range of tools for all types of applications. Pneumatic tools at higher horsepower have an unfavorable weight to power ratio, but do not suffer contamination problems due to a dirty environment. Air tools include a wide range of products for specific grinding applications. Unfortunately, air tools have to be maintained quite a bit to keep performance up. Keeping air lines clear of condensation and oiled is important for tool life and performance. Keeping air lines and connections free of leaks is critical for CFPM and SFPM so you can obtain peak performance from your abrasive.

Pneumatic	RPM		Horsepower		Accessories		Common Abrasives
Large Right Angle	10,000 5/8-11 Thread		1		Backing Pads Locking Nuts Wrenches		4-1/2, 5" RFD 4-1/2, 5" Flap Disc 5/8-11" Flap, Combination Wheels 4-1/2, 5" Type 27 Bonded Wheels 4-1/2, 5" Wire Brushes
	6,000 5/8-11 Thread		1 to 4		Backing Pads Locking Nuts Wrenches		7, 9" RFD 7, 9" Flap Disc 5/8-11" Flap, Combination Wheels 7, 9" Type 27 Bonded Wheels 7, 9" Wire Brushes
Small Right Angle	7,000		1		Locking Nuts Wrenches		4-1/2" RFD Pistol Type
	10,000		.5 to 1		1/8 to 3/8 Collets Wrenches		3" Quick-Loks 3" and Larger Mounted Flap/Combination Wheels Mounted Stones, Points, Burrs, Brushes Square/Cross Pads Cone Points Cartridge Rolls
	20,000		.3 to .5		1/8 to 3/8 Collets Wrenches		2" and Smaller Quick-Loks 2" and Smaller Mounted Flap/Combination Wheels Mounted Stones, Points, Burrs, Brushes Square/Cross Pads Cone Points Cartridge Rolls
Straight Die/ Extended Straight Die	7,000		1 to 4		1/8 to 1/2 Collets Wrenches		Solid & Pneumatic drums for Coated Nonwoven Belts 4 to 8" Unmounted Flap Wheel Combination Wheels
	10,000 to 20,000		1		1/8 to 3/8 Collets Wrenches		3" or Larger Mounted Flap/Combination Wheels 3" or Larger Square/Cross Pads Mounted Stones, Points and Burrs
	20,000 to 30,000		.25 to 1		1/8 to 3/8 Collets Wrenches		2" or Smaller Mounted Flap/Combination Wheels 2" or Smaller Square/Cross Pads No Lap Bands Cartridge Rolls Cone Points
Specialty	10,000 Dynafile		.5 to 1		Various Arms & Contact Wheels		1/8 to 1 x 12, 18, 20-1/2, 24" Coated & Nonwoven Belts
	RA Waterfeed		1 to 4		Backing Pads Locking Nuts Wrenches		4, 5" Surface Conditioning Hook & Loop Discs Surface Conditioning RFD 4, 5" Diamond Hook & Loop Disc
	Belt		1 to 4		Drums Rollers		Coated/Nonwoven Belts
	Drum		1 to 4		Solid and Pneumatic Drums		Coated and Nonwoven Belts Large 5/8-11" Flap and Combination Wheels

Flexible Shaft Tools have a single or three phase variable speed motor connected to a hand piece by a flexible shaft. The advantage is that you get incredible power, consistent speed and horsepower with a completely sealed, air cooled motor. This allows the advantages of electric to be used in dirty environments. Another advantage of flexible shaft is using variable speeds and different hand pieces to accomplish all sorts of grinding applications with only one tool. In hard grinding applications in which much horsepower is required, flex shaft is hard to beat.

Flex Shaft	RPM		Horsepower		Accessories		Common Abrasives
Right Angle	10,000 5/8-11 Thread		1 to 4		Small to Large Attachments Backing Pads Locking Nuts		4-1/2, 5" RFD 4-1/2, 5" Flap Disc 5/8-11" Flap, Combination Wheels 4-1/2, 5" Type 27 Bonded Wheels 4-1/2, 5" Wire Brushes
	6,000 5/8-11 Thread		1 to 4		Small to Large Attachments Backing Pads Locking Nuts		7, 9" RFD 7, 9" Flap Disc 5/8-11" Flap, Combination Wheels 7, 9" Type 27 Bonded Wheels 7, 9" Wire Brushes
Straight	1,000 to 25,000		1 to 4		Small to Large Attachments 1/8 to 1/2" Collets Wrenches		3" or Larger Mounted Flap/Combination Wheels 3" or Larger Square/Cross Pads Mounted Stones, Points and Burrs
Specialty	Belt/Drum 1,000 to 25,000		1 to 4		Contact Arms and Wheels Different Diameter Wheels Solid and Pneumatic Drums		Coated and Nonwoven Belts Large 5/8-11" Flap and Combination Wheels

 

Mechanical Tools

Stroke Sanders are large belt machines that produces consistent straight line scratch patterns. Stroke sanders are used primarily for stainless and aluminum finishing. The machine operator uses a graphite block to push the belt on the material that needs to be finished and moves the part on a carriage so the belt can cover the entire part.

A Wide Belt Machine uses a conveyor belt to bring parts in contact with an enclosed belt in the machine. Wide belt machines are used primarily for deburring applications on finished parts. Wide belt machines work well but take some adjustments to get required removal ratio.

2 and 3 Wheel Mounted Grinders run common sized belts for all types of grinding applications. They can be bench or pedestal mounted.

Platen or Disc Grinders use PSA discs as the abrasive. Platen grinders have the advantage of a solid  backing plate, which can grind with more precision and offer a larger grinding area than wheel and bench grinders.

Backstand is a very common machine that has an exposed contact wheel but an enclosed belt. Used for many different types of contact wheels, parts are ground on the contact wheel for all types of grinding applications. Common sizes include 2, 3 and 4 x 132”.

A Swing Grinder is an electric motor mounted on a swing that gives the operator control up, down and side to side. Belt and solid wheel grinders can be used for a variety of applications.

Bore Polishers are electric motors mounted to a solid mandrel varying in length and diameter, depending on the diameter of the tube.  They are used with Flap Wheels to polish the inside of stainless steel tubing that is used in dairy, chemical and pharmaceutical applications.