Flexovit Abrasives Training

1-800-689-FLEX flexovitabrasives.com

Flexovit Overview


Topics

1. Introduction to Flexovit

2. Abrasives Overview, with Focus on Reinforced Resin Bonded

3. Introduction to Flexovit Product Tiers

4. Grinding and Cutoff Wheel Safety


Corporate Offices & Manufacturing Facility

Located in

Angola, New York

• 100,000 Square

Foot manufacturing

facility.

• Most technologically-advanced grinding wheel manufacturer

in North America.


Manufacturing Facility

• Flexovit manufactures the entire bonded abrasive wheel including the die-cast spin-on hubs, and fiberglass reinforcements.


• On-Site R&D Lab

Completed at our factory...

• On-Site Testing Lab

• ISO 9001:2008 Certified

Product Testing


2. Abrasives Overview- with Focus on Reinforced Resin Bonded




Topics


Abrasives Overview- with Focus on Reinforced Resin Bonded

The four main abrasive systems are:

Bonded Abrasives

Coated Abrasives

Non Woven Abrasives

Superabrasives


Bonded Abrasive Wheels

The resin bond is tough and resilient. Resin bond wheels may also be reinforced with fiberglass mesh for added strength. Because of their strength they are recommended for thin cutoff wheels, and for grinding wheels that are subjected to severe lateral pressure or shock, including wheels used on portable power tools.

Resin Bond

Vitrified BondIs a rigid bond, somewhat fragile, used primarily for precision grinding and finishing operations. It is not recommended for surface speeds over 6,500 feet per minute. Vitrified wheels are typically used on stationary machines.

Rubber BondComposed of synthetic or natural rubber. It is used extensively on thin cutoff wheels for burr-free cuts, as well as regulating wheels on centerless grinders. These wheels are relatively fragile, and therefore used on stationary machines with a fixed cutting plane and securely clamped workpiece.


WheelLabel

ResinBonds

FiberglassReinforcing

AbrasiveGrains

ArborRing

Spin-onHub

Resin Bonded Abrasive Wheels - How a Grinding Wheel is Made: Components


• Tough, blocky, wedge

shaped grain.

• Performs well on carbon

steel, stainless steel and

aluminum.

• Extremely hard and sharp, but fractures more easily than aluminum oxide.

• Performs well on Cast Iron, Nonferrous Metals (Aluminum) and Non-Metallic materials including Concrete, brick, marble and glass.

• Very tough, sharp, and dense.

• Lends itself to higher temperatures and heavier pressures present in high-stock removal applications

The four main types of abrasive grains used in Resin Bonded wheels are:

AluminumOxide

SiliconCarbide Zirconia

Alumina Ceramic

Resin Bonded Abrasive Wheels - How a Grinding Wheel is Made: Grains

• Sharp microcrystalline grain-cuts aggressively under light to moderate pressure.

• Its quick cutting capability makes it suitable for grinding stainless steel, titanium, and high-nickel alloys.


Abrasive grains are sized by passing them over screens having a certain number of openings per linear inch. The number of openings per linear inch in the screen through which the particles just pass determines the grit size. Resin bonded wheels typically use relatively coarse grits such as 24 and 36.

Determining Grit Size:

Coarse Grit Size (30 Grit) Fine Grit Size (108 Grit)

Resin Bonded Abrasive Wheels - How a Grinding Wheel is Made: Grains


7 x 1/4 x 5/8-11 Triple-Layered fiberglass-Reinforced, Depressed-Center Grinding Wheel, Product Code A5356H

Grinding Matrix

Backing Matrix

High tensile fiberglass mesh is incorporated in the wheel for more durability.

Resin Bonded Abrasive Wheels - How a Grinding Wheel is Made: Fiberglass Reinforcing


A30Sex.

1.) Abrasive Grain

AA = Aluminum Oxide

C = Silicon Carbide

ZA = Zirconia Alumina

CG = Ceramic

2.) Grit Size

3016 Coarse

30

60

Medium

120 Very Fine

Fine

3.) Grade/Hardness*

SM Soft

R Harder

Z Hardest

T HarderS

*Each grain of abrasives is joined to other grains by a bond material. The strength with which this bond hold the grains is known as the grade or 'hardness' of the wheel. Grade or hardness is expressed by a letter of the alphabet, with 'A' being the softest and 'Z' indicating the hardest bond.

Resin Bonded Abrasive Wheels - Understanding the Specification (Spec)


The Cutting Tool Principle:

WheelBond

AbrasiveGrains Workpiece

• Abrasive grain begins to cut chips from the workpiece’s surface. As it does, the grain begins to wear down. It fractures, presenting a new sharp edge.

• Before the edges of the abrasive grain become too dull, they are torn away from the wheel bond, allowing other abrasive grains to come into play.

• Other abrasive grains are revealed as the wheel bond wears from contact with the workpiece.

Resin Bonded Abrasive Wheels - How a Grinding Wheel Works


Flexovit’s Hardbak wheel design boosts productivity and safety on the shop floor by eliminating premature shedding and shearing of grain from the leading edge of the grinding face.

Hardbak is incorporated in the design of all Flexovit 7” and 9” depressed center grinding wheels as well as in all premium (Flexon) and semi-premium (Metalhog) depressed center grinding wheels.

Flexovit Wheel with Hardbak

Competitor Wheelwithout Hardbak

The Hardbak design incorporates a thin layer of relatively fine abrasive grain and hard bond sandwiched between two full diameters of fiberglass. The remainder of the wheel is comprised of two thick layers of coarse grit and bond. These are separated by a third full diameter of fiberglass reinforcing. The leading edge of the grinding face is now resistant to grain shedding or chipping, allowing the coarser grain to fully do its work and eliminate the hazard of flying chunks of abrasive.

Resin Bonded Abrasive Wheels - Wheel Construction: Hardbak


Type 28: Saucer Shaped WheelsThis wheel operates at a wider contact area than the Type 27, resulting sometimes in a better finish, but it also offers more aggressive stock removal. It can be used at shallower angles, 10 to 15 degrees from workpiece.

Type 29: Flared Up (Found in Zircotex/ZircoMax Flap Discs & Flexcel Wheels) Fiberglass reinforced depressed center product, featuring a flared profile with a convex surface on one side. This shape allows a wide contact area, and can be used at a greater variety of angles, anywhere from 10 to 30 degrees.

Type 1: FlatA round, flat wheel with a hole in the middle. These wheels are designed for grinding or cutting on the periphery, or edge, of the wheel only. They may or may not be fiberglass reinforced.

Depressed-Center WheelsGrinding wheels are designed to be used at a 30 degree angle from the workpiece. Cutoff wheels are designed to be used at a 90 degree angle to the workpiece and may be used for flush cutting.

Type 27:

Resin Bonded Abrasive Wheels Wheel Types - Reinforced


Type 11: Flaring Cup Wheels

Plugs & ConesThese are designed for difficult to reach places, such as odd-shaped castings. Good for internal grinding as well.

Type 16,1718 & 18R:

- Also called: ‘Cup Rocks’ or ‘Cupstones’Resin bonded cup wheels are used for heavy stock removal applications. Unlike depressed center wheels, these wheels are not fiberglass reinforced.

Type 1: Flat - Bench Grinder WheelsA round, flat wheel with a hole in the middle. These wheels are designed for grinding or cutting on the periphery, or edge, of the wheel only.

Resin Bonded Abrasive Wheels Wheel Types - Non Reinforced


Topics






Depressed Center Wheels, Circular Saw Wheels, & Stationary Saw Wheels

Depressed Center Grinding, Cutoff and Combination Wheels, Cup Wheels, Die Grinder Wheels, Cutoff Wheels & Resin Fiber Sanding Discs.

Thin Cutoff Wheels & Depressed Center Thin Cutoff Wheels

Semi-Flexible Grinding / Blending / Finishing Discs

Super Flap Discs High Density Super Flap Discs

Depressed Center Wheels, Cup Wheels, Plugs & Cones, Bench Grinder Wheels, Mounted Points, Die Grinder Wheels, Cutoff Wheels, Coated Abrasive Products, Non-Woven Abrasive Products, Carbide Burs, & Wire Brushes.

Flexovit Product Tiers Product Offerings

Depressed Center Wheels, Cutoff Wheels, Resin Fiber Sanding Discs


Metalhog wheels incorporate a blend of premium, semi-premium, and standard abrasive grains with custom bond systems. This produces an extremely aggressive wheel, without sacrificing wheel life.

Offering a combination of premium Zirconia and Ceramic grains with advanced bond systems, these wheels deliver the highest productivity.

Flexovit’s Razorblade series of thin cutoff wheels for angle grinders are an indispensable tool for the metalworker in both production and maintenance applications. Choose from 5 versatile specs depending on the job requirement. Available in Type 1 as well as Type 27.

These semi-flexible wheels remove material like depressed center wheel, yet blend and finish like a resin fiber disc. Flexs to contoured surfaces delivering a smooth finish without gouging.

Extremely productive & efficient. Ideal for high production grinding, blending , deburring and finishing, it performs well on a variety of materials.

Delivers twice the removal rate as our conventional Zircotex discs. Provides extremely long life and is our most productive flap disc.

The wheels are the hardest working aluminum oxide wheels available. Precision made to ensure smooth and safe operation, these versatile products set the standard for fast material removal, and rugged reliability and long life.

Flexovit Product Tiers Descriptions

Specially designed to optimize performance on a particular material. Flexovit Specialist wheels are available for a variety of materials including; stainless steel, aluminum and concrete/masonry.


Topics






Wheel ManufacturerMachine Builder

User

Who’s responsibility is safety?


MACHINE SHOULD BE WELL MAINTAINED. Wheels can only be used on machines regularly maintained by qualified personnel including periodic check of free running spindle speed (RPM).

Machine must be adequately guarded. Wheels can only be used on machines with safety guards that meet A.N.S.I. and O.S.H.A. specifications. Generally, a safety guard should enclose one-half of the wheel.

The machine builder must make certain at the time of manufacture that the

machine is of suitable design and properly guarded for the operation.

MACHINE MUST HAVE PROPER FLANGES. Wheels can only be used between flanges mounted in accordance with A.N.S.I. specifications. Generally, flanges should be at least one-third the diameter of the wheel. Flanges should be kept in good repair and must be checked periodically for flatness, burrs or wear.

Machine Builder


The wheel manufacturer must make certain that the wheels are manufactured to meet or exceed specification and have been tested in accordance with the ANSI standard B7.1- 2000 safety requirements for the use care and protection of abrasive wheels and are marked with the maximum operating speed as well as all necessary safety information.

Wheel Manufacturer


Features of a Flexovit Wheel Label


As we covered earlier, grinding wheels are made of thousands of small abrasive grains that have been bonded together using an organic resin compound. The bond must be strong enough to hold the abrasive grains in place, yet friable enough to release dull grain and expose fresh cutting points. (Friable refers to the property that makes the abrasive

capable of breaking down during the grinding process.) An unbreakable wheel simply would not grind.

ResinBonds

AbrasiveGrains

The resin holds the wheel together. Poor qualityresins can cause quick wear or wheeldisintegration.

Fiberglass reinforcements of varying sizes and mesh, are used to strengthen the wheel. The material must first be coated with a resin to facilitate proper bonding to the abrasive matrix.

FiberglassReinforcing

Wheel Manufacturer


The user is responsible for the proper handling, storage and inspection of grinding wheels after receiving the product.

The user must maintain the equipment in safe operating condition at all times. This includes periodic speed checks of the equipment.

All operating personnel must be instructed in the safe use of their particular equipment. It is imperative they use the proper wheel for the machine and they must be sure the maximum rated machine speed DOES NOT exceed that of the wheel.

Protection of operating personnel, as well as those in adjacent areas, must be maintained at all times. It is the users responsibility to use and maintain guards and other protective devices.

User


Depressed center wheels -should be stored flat or hung on pins.

Cutoff wheels -should be stored flat. Do not stand them on their edge as they are subject to warping.

Bench and pedestal wheels -should be stored flat or standing on their edge and each should be stored in a protective corrugated sleeve.

Wheels should NOT be stored/subject to (causes of bond degradation):a) Water or other solventsb) Any temperature or humidity condition that causes condensation on the wheelsc) Freezing temperatures- special attention should be taken for wheels stored in mobile storage areas.

If a grinding wheel has been or is suspected of having been damaged, DO NOT USE IT.

Suitable racks, bins drawers, pins or boxes shall be provided to store the various types of wheels.

User - Handling and Storage


USE PROPER FLANGESBoth flanges, of any type, between which a wheel is mounted, should be of the same diameter and have equal bearing surfaces. Depressed center wheels, over 7” in diameter, should have a CP50 adapter. Check all flanges for wear and deflection.

DO NOT OVER TIGHTENPlease tighten the wheel snugly! Over tightening causes several problems. It can bend the flanges by crushing them. It can also set up dangerous stresses in the wheel, which when centrifugal force is introduced, can cause the wheel to fail.

USE CORRECT MACHINE FOR WHEELAlways make sure you have the proper machine for the wheel you are using. DO NOT USE A DEPRESSED CENTER WHEEL ON A PISTOL GRIP SANDER. Always check wheel speeds before mounting!

User - Machine


INSPECT WHEELSVisually inspect all wheels before mounting. Also inspect the packaging. If the wheel or packaging show any evidence of abuse, please do not mount them. Defects such as broken wheels, chips and gouges can be detected visually. Cracks in abrasive wheels are frequently not visible to the naked eye.

To test for cracks in a vitrified wheel (bench or pedestal), administer a ring test.

For organic bonded wheels (depressed center or cutoff), use proper start up procedures. (see ANSI 9.8 pg 111)

CHECK SPEEDSAlways compare maximum wheel and machine speed. The machine speed must be the lesser of the two.

User - Mounting


USE PROPER GUARDSPlease use a guard! If breakage of abrasive wheels could be prevented, there would be no need for a guard. Conversely, if all machines could be completely guarded there would be no cause for worry about wheel breakage. However, both must be considered. Everything must be done to prevent wheel breakage and proper guards must be used. When using a grinding or cutting wheel ensure that the machine guard is positioned between the wheel and the operator.

CHECK MACHINE SPEEDAir tools should be checked every 20 hours or once per week. Electric tools should be tested monthly. All tools should be tested after repair or maintenance.

User - Mounting


SAFETY WEARProper eye and body protection not only makes good

sense, it is the law in parts of our country. Glasses,

gloves, goggles, shields and ear protection….

Whatever you can practically handle. Keep in mind,

The peripheral speed of a 7” grinding wheel equals

That of a .38 caliber bullet. Even a small piece of debris

Is extremely dangerous.

START UP When starting any grinding wheel, whether new or used, stay away from it! If it is a portable application, start the wheel with the rotation turning away from you or in a protected area. If it is a stationary application, stand off to on side when you start up.

User - Use and Operation


Grinding

Smoothing

Notching

All wheels have a particular application. Please use the wheel for what it was designed.

Use and Operation - Proper Use


Deburring or beveling on the side of a type 1 cutoff wheel. This will sheer reinforcing that will cause premature failure when the wheel is subject to heavy cutting.

Too shallow a grinding angle with type 27 depressed center wheels causing an undermining of the reinforcing. This sets up for wheel failure when aggressive grinding pressure is introduced onto the wheel.

Improperly tightened flanges on a large diameter cutoff wheel. Loose flanges spin against the wheel rather than supporting the wheel. This results in the arbor of the wheel failing.

Use and Operation - Common Misuses


1. Check all wheels for cracks or damage before use.

2. Run the wheel in a protected area for one minute before grinding.

3. Don't use wheels that have been dropped or otherwise damaged.

4. Don't apply side pressure on any Type 1 straight wheel or Type 27 thin wheel.

5. Don't use a grinding wheel with a rated speed less than that of the grinder.

Observe These Safety Tips:


For Complete Safety Information please refer to the

American National Standards Book ANSI B7.1-2000


We Hope You Found This Presentation Informative.

Thank You for Your Time.

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Flexovit Abrasives Training