What are the different types of abrasive grain?
THE 3 MOST COMMON GRAINS
- Ceramic Alumina – Ceramic abrasives provide the longest life & fastest cut rate of all coated abrasives. They are the newest grain innovation and represent the ultimate in performance, providing an aggressive, consistent cut under moderate to high pressure. Ceramic is usually red or orange in color. Used primarily on metal applications. Ceramic is available in grits 24-120.
- Zirconia Alumina– Zirconia Alumina is commonly referred to as Zirc or Zirconium. Zirc is ideal for coarse to medium grit applications on metal (best choice for abusive applications). Zirc is usually green or blue in color. Works best under high pressure (which is required for the grain to fracture exposing new sharp edges). It has large fracture planes and it self-sharpens as it cuts. Zirc is available in grits 24-180.
- Aluminum Oxide– Aluminum Oxide is the most common & least expensive. Good starting point for most metal and wood applications. Aluminum Oxide is usually brown or reddish in color, but can be blue, green or yellow (which usually indicates the presence of a grinding aid/lubricant). It is durable with tough cutting edges, but it dulls during use. Aluminum Oxide is available in grits 24-600.
LESS COMMON GRAINS
- Silicon Carbide– Silicon Carbide is good for grinding glass, plastic, rubber, paint, wood products, titanium alloys and cast iron. Silicon Carbide is black in color. It is a sharp, hard synthetic abrasive. Its friable grains fracture to continually expose new cutting edges and permit fast stock removal.
- Crocus– Crocus is reddish brown in color. It is a soft material made from iron oxide. It is the finest natural grain produced. Its applications include cleaning and extremely fine polishing of soft materials such as gold.
- Emery– Emery is a dark gray round-shaped natural grain. It is better used as a polishing grain than a cutting grain. It is used for cleaning and polishing metals.
- Garnet– Garnet is a reddish brown natural grain. It is relatively sharp and has a medium hardness. Its durability cannot be compared to that of synthetic abrasives (aluminum oxide) and thus is not used much any longer. It is used for finishing applications in soft woods such as fir or pine.
Silicon Carbide vs. Aluminum Oxide
- Both grains have advantages on certain materials.
- S/C has a long sharp needle-like grain structure which permits fast stock removal, but generally has a short life. Aluminum oxide has a “blocky’ grain structure. This durable grain generally will last longer than S/C.
- S/C is generally the best choice for glass, plastic and rubber. It is also non-contaminating which makes it popular in aerospace applications – especially on titanium.
- S/C is available in grits 16 – 600.
- A/O is a tough durable grain that works reasonably well on most materials. It is the most common & least expensive. It’s “blocky” shape does not allow it to fracture easily, so it does not stay sharp through it’s usable life.
- AO is a good starting point for most metal and wood applications. (Note: Zirc and Ceramic are better choices on most metal applications.)
- AO is available in grits 24 – 800
Zirc vs. Ceramic
- Both grains are considered “Hi-Performance”. Both will remove metal faster and last longer than all aluminum oxide or silicon carbide products. These Hi-Performance grains have the ability to constantly resharpen as they wear, providing fast cutting action through their usable life. Used primarily on metal applications
- Z/A – commonly referred to as Zirc or Zirconium. They are ideal for coarse to medium grit applications on metal (best choice for abusive applications).
- Works best under high pressure (which is required for the grain to fracture exposing new sharp edges).
- Zirc was the first innovation in self-sharpening grain technology. Zirc grain has “large fracture planes”, which means a large portion of the grains flakes away as they resharpen, limiting the number of times the grain can resharpen itself.
- Zirc is available in grits 24 -180.
- C/A – ceramic abrasives are the newest innovation in grain technology. They provide the longest life & fastest cut rate of all coated abrasives.
- They represent the ultimate in performance, providing an aggressive, consistent cut under moderate to high pressure. Ceramic grains feature very small fracture planes which allow each granule to constantly resharpen and provide extremely consistent stock removal through its usable life.
- Ceramic is available in grits 24-220.
What are the different types of backings used in coated abrasives?
- Cloth backings come in various weights, from Stiffest to the most Flexible – (Y, X, J, J-Flex)
- “Y” Weight – This extremely heavy duty cloth is used for tough applications. It is usually made of Polyester for added strength & tear resistance.
- “X” Weight – This heavy cloth, also called drills, is recommended for all ordinary machine sanding operations. Considered general purpose.
- “J” Weight – This flexible, lightweight cloth, also called jeans, is used where more flexibility is needed, such as with contour sanding.
- “J-Flex” Weight – This highly flexible, lightweight jeans cloth is used when extreme flexibility is desired.
- Paper – Paper backings come in different paper weights, designated by letters, are available for different applications.
- “A” Weight – This light touch 40# paper is primarily used in finishing operations where fine grits are required.
- “C” Weight – This medium light 70# paper is used when some pliability and strength are required. It can be used in folded or flat areas and is ideal for cabinetwork. This backing is available in fine to medium grits.
- “D” Weight – This medium heavy 90# paper is available in medium and coarse grits.
- “E” Weight – This strong 130# paper is used for belts, discs, rolls and very coarse sheets.
- “F” Weight – This 165# paper is used for narrow and wide belts, metal and crankshaft polishing rolls, and cabinet and furniture industries.
- Fiber – Fiber is a hard, durable material with great mechanical strength. It is used exclusively to make resin fiber discs.
- Film – Used most often for DA sanding discs for orbital sanders. The film backing is more durable than paper & can be used wet or dry.
What is the best way to store coated abrasives?
The best way to have abrasive products retain maximum performance and work life is to store them properly. The bonding and backing materials used in abrasives are sensitive to changes in temperature and humidity. Abrasives are best stored at temperature levels of 60 to 80 degrees Fahrenheit and a 35 to 50 percent relative humidity. Products should be kept in their cartons until you are ready to use them. Cartons should be kept away from heat sources, cold walls, and off of damp floors.
How much longer will Zirc or Ceramic last compared to Aluminum Oxide?
Ceramic grains are the newest technology; their micro grain structure allows for smaller pieces to break away during the grinding process which makes them last longer than Zirc.
Aluminum oxide on the other hand gets dull as it wears; the stock removal rate drops dramatically as the grains dull. As they continue to dull, more pressure is required to continue removing material, which leads to excessive heat & operator fatigue.
What is the best abrasive to use?
The answer depends on how much pressure is being used and even then, the recommendations need to be considered only as a “general guideline”:
|Sanded Material||Best||Better||GoodCarbon Steel & Cast Iron||Moderate to Heavy Pressure||Ceramic Plus||Zirc Plus / Zirc||AOLight Pressure||Zirc PC||AO||Stainless Steel & Exotic Metal||Moderate to Heavy Pressure||Ceramic Plus||Zirc Plus||AOLight Pressure||Zirc PC||AO Plus||AOAluminum**||Moderate to Heavy Pressure||Ceramic Plus||Zirc Plus||AOLight Pressure||AO Plus||AO||SC"Non-Ferrous (Titanium||Copper||Brass)"||Moderate to Heavy Pressure||Ceramic Plus||Zirc Plus / Zirc||AOLight Pressure||AO Plus||AO||SCWood||Pressure does not affect performance||Ceramic OC||AO Open Coat||AO|
** Due to the inherent clogging involved when sanding most Aluminum, we recommend either using products with Grinding Aids or using a Grease Stick to lubricate the abrasive to help prevent loading.
|Legend:||Ceramic Plus:||Ceramic Alumina with a grinding aid on a heavy Y-wt. polyester backingCeramic OC:||Ceramic Alumina Open Coat on a heavy duty backingZirc Plus:||Zirconia Alumina with a grind aid on a heavy Y-wt. polyester backingZirc:||Zirconia Alumina on a heavy Y-wt. polyester backingZirc PC:||Zirconia Alumina on a X-wt poly/cotton backingAO Plus:||Aluminum Oxide with a grinding aid (available on Y-wt. or J-Flex backing)AO:||Aluminum Oxide (available on Y, X or J-wt. backing)SC:||Silicon Carbide on a heavy Y-wt. polyester backing|
What does “PLUS” mean in your material descriptions?
- We use the term Plus on several of our materials. The term refers to the product having a Grinding Aid. Grinding Aids are an additional coating (top size coat) on top of the abrasive grains. Depending on their type, they can:
- Reduce grinding heat & prevent discoloration of the metal
- Reduce loading/clogging
Note: Abrasives with Grinding Aids should be used dry
How do you Calculate Belt Speed?
When I sand Aluminum, my belts get clogged prematurely. Is there anything I can do?
Yes, we offer a couple of options:
- Use our Firestorm Ceramic or Zirc Plus belts, both have a grinding aid that helps prevent loading.
- We sell a grease stick that acts as a lubricant. A small amount applied to the belt while running, prevents the aluminum from adhering.
- DO NOT use a belt cleaning stick, they are designed for cleaning belts that have been used on wood, they will not remove aluminum that is stuck on the belt.
Can you make special size belts?
I like the belt I’m using from another supplier, but I don’t see that material listed on your website, do you offer other materials?
What are Non-Woven Abrasives?
These products are often referred to as “Scotch Bright®” or three dimensional abrasives. Abrasive grains are bonded to flexible nylon fibers, which provide a controlled, consistent finish. The “open weave” construction provides a continuous supply of new grain when fiber and old grain wear away. The flexible “spring-like” design reduces the chance of undercutting or gouging the work piece.
Nonwoven abrasives can be divided into six categories:
- Flex-N-Finish– Non-Woven clean & finish products are generally hand-operated. They are not as strong in nature as other non-woven products because less grain, fiber and resin are used in their production. Clean & finish products generally include hand pads, sheets and rolls.
- Heavy Duty & Hi-Strength Flex-N-Finish– HD & HS Non-Woven clean & finish products are designed for machine use and can handle higher RPM’s. They are made with stronger nylon fibers and additional resin. They are not as strong as surface conditioning products, but they can be ganged together is disc form to remove burs, particularly on threaded parts. They are also great for applying a consistent satin finish on irregular shaped parts. The finish will be consistent on part-after-part.
- Surface Conditioning– Surface conditioning refers to the changing of a product’s surface, without removing or damaging the base material. These products are used in mechanical operations and include discs and belts.
- Flex-N-Strip Products – Extra coarse silicon carbide grain is bonded to stiff extruded nylon fibers with a flexible resin. They are excellent for removing coatings from wood, metal and plastic. Also effective at paint & rust removal.
- Convolute Wheels – Formed by wrapping and bonding web material impregnated with abrasive grain and resin around a center core. Because they are “wrapped”, they must be run in the direction of the arrow printed on them. Very effective on a variety of deburring & polishing applications.
- Unitized Wheels – Formed by pressing web material impregnated with abrasive grain and resin into a slab. Wheels are then cut from the slab. These products can be run in either direction, so they do not have directional arrows printed on them like convolute wheels.
What materials can non-woven abrasives be used on?
- Stainless Steel
- Chrome Plate
In what applications are non-woven abrasives used?
- Decorative finishing
- Defuzzing of wood
- Flash removal from plastic parts
- Removing oxides and rusts