General Information on Abrasive Belts
A considerable number of issues are involved in choosing the right abrasive material for any given application. The information below will provide some good general guidelines toward ordering a product to meet your needs.

Abrasive Grains
The two abrasive grains most commonly used today are aluminum oxide and silicon carbide. Aluminum oxide is suitable to most general purpose applications and is specified for use on wood and most metals. Silicon carbide grain is sharper but more brittle than aluminum oxide grain, and should be used on applications that are either very hard (i.e. glass, stone, porcelain and ceramics) or very soft (i.e. rubber and plastics). Silicon carbide grain tends to be more aggressive, but of shorter life than aluminum oxide. Zirconia alumina (a combination of zirconia with aluminum oxide) grains are both sharp and durable, providing fast stock removal and longer life. They are used to greatest advantage in coarse grits on heavy-duty metalworking stock removal applications. More recently ceramic grains have been made available, either by themselves or in combination with aluminum oxide or zirconia grains. While more costly they often can improve grinding performance and cost-effectiveness of the product.

Backing Materials & Flexibility
The backing materials for abrasive belts are generally made from cloth or paper. While the backing paper comes in various thickness/strength (weights), ranging from A-weight to F-weight, only the heaviest of these (E & F weight) paper are suitable for belts, and paper backed belts are rarely used and found mostly in light duty applications. Cloth backing material is made either from cotton or polyester, or some combination of the two. Cotton backed materials are acceptable in most general purpose and some heavy duty applications. Polyester or cotton/polyester combination materials tend to be stronger, and as such, may yield longer life in heavy duty applications. Polyester backed materials also have the advantage of being water resistant, so can be used with water as a coolant (only oil based coolants can be used with cotton backed materials). Special coating of some backing materials make them waterproof. Their advantage is in their ability to be used fully submersed in water, in addition to being washable. The thickness and flexibility of cloth backed materials is designated by gradings of J-weight (most flexible), X-weight (standard), and Y-weight (toughest, least flexible). Once made materials may further be made more flexible by running it over rollers either straight or at 45% angles. As such within any named weight, there are variations of flexibility. For the purposes of grinding belts, there is a tradeout between flexibility and belt life, in that a more flexible material will yield a shorter production life.

Coating - Closed Coat vs. Open Coat
Coated abrasives are manufactured in either closed coat or open coat. Closed coat materials have 100% grain coverage on the backing material, while open coat has approximately 70% grain coverage. As such, closed coat materials tend to be more aggressive and provide longer life in most applications. The lower grain coverage of open coat materials, however, has a distinct advantage on applications involving soft materials (i.e. soft woods, soft aluminum) in that it prevents the material from loading up and prematurely ending the useful life of the belt.

Price versus Value
Coated abrasive materials are engineered for specific uses with related features and benefits. As such the selection of material should never be based on price alone. It shoud be made on the basis of what it does and how efficiently it does it. When buying a belt or disc or other product, what you are really buying is "finish" on your product. Keep in mind the simple equation: PRICE divided by PERFORMANCE equals VALUE.

High Performance Materials
SH - Grain: Ceramic, Coat: Closed, Weight: Y, Backing: Polyester, Applications: Deburring and grinding iron, steel and aluminum castings; heavy structural work; weld grinding on steels including stainless.
R203 - Grain: Zirconia & A/O, Coat: Closed, Weight: Y, Backing: Polyester, Applications: Deburring and grinding hard metals, alloys and stainless steel; grinding aids in super-size coat and bonding system cut heat and add life.
R205 - Grain: Zirconia & A/O, Coat: Closed, Weight: Y, Backing: Polyester, Applications: Deburring and grinding hard ferrous and non-ferrous metals, alloys and stainless steel requiring sharp cutting without heat build-up.
ZH - Grain: Zirconia & A/O, Coat: Closed, Weight: X, Backing: Polyester, Applications: Deburring and grinding iron, steel and aluminum castings; heavy structural work; weld grinding steels including stainless.
R821 - Grain: Zirconia & A/O, Coat: Closed, Weight: Y, Backing: Cotton, Applications: Original NorzonŽ Brand product for heavy stock removal from hard metals and alloys via durable grain and all-cotton backing that helps dissipate heat for longer life.
23MX - Grain: A/O & Ceramic, Coat: Closed, Weight: X, Backing: Poly/Cotton, Applications: Amended combination of grains cuts better, stays sharp, and lasts longer; grinding and cleaning welds; cleaning, smoothing and polishing ferrous and non-ferrous metals including stainless steel.
CH - Grain: Silicon Carbide, Coat: Closed, Weight: X, Backing: Polyester, Applications: Grinding glass, ceramics, plastics, fiberglass, rubber, leather and non-ferrous metals; finishing iron, bronze, brass and aluminum castings; satin finishing sheet metals.
2AH - Grain: Aluminum Oxide, Coat: Closed, Weight: X, Backing: Polyester, Applications: Deburring iron, steel and aluminum castings; grinding metal castings as well as bumps, oxidations and roughness on metals.

Premium Grade Materials
1AX - Grain: Aluminum Oxide, Coat: Closed, Weight: X, Backing: Cotton, Applications: Specially heat treated grain last longer, cuts faster, and improves continuity of finish. Grinding and cleaning welds; cleaning, smoothing and polishing ferrous and non-ferrous metal parts and components.
W25 - Grain: Aluminum Oxide, Coat: Open, Weight: Y, Backing: Poly/Cotton, Applications: Wide and narrow belt sanding of soft or hard wood; first belt material ever engineered for repeated washings; also good for applying brushed finishes to metals with controlled stock removal or minimal loading.
CW - Grain: Silicon Carbide, Coat: Closed, Weight: X, Backing: Cotton, Applications: Wet grinding glass or ceramics; dry grinding plastics, fiberglass, rubber, leather and non-ferrous metals; finishing iron, bronze, brass and aluminum castings; satin finishing sheet metals.
R544 - Grain: Silocon Carbide, Coat: Closed, Weight: X, Backing: Poly/Cotton, Applications: Dry grinding glass, ceramics, plastics, fiberglass, rubber, leather and non-ferrous metals; finishing iron, bronze, brass and aluminum castings; satin finishing sheet metals.
2AJ - Grain: Aluminum Oxide, Coat: Closed, Weight: J, Backing: Cotton, Applications: Cleaning and polishing contoured ferrous and non-ferrous components including final steps prior to plating processes.
KAF - Grain: Aluminum Oxide, Coat: Open, Weight: J, Backing: Cotton, Applications: Cleaning and finishing intricately contoured ferrous and non-ferrous components including cutlery and plumbing fixtures; polishing wooden panels and profiles.

Quality Materials

LAX - Grain: Aluminum Oxide, Coat: Closed, Weight: X, Backing: Cotton, Applications: Grinding and cleaning ordinary steel, nonferrous metals and their alloys. Also suitable for closed-coat applications in general woodworking.
R145 - Grain: Aluminum Oxide, Coat: Closed, Weight: X, Backing: Poly/Cotton, Applications: Grinding and finishing ferrous and non-ferrous metals as well as sanding hardwoods. Base adhesion and grain retention engineered for improved edge wear in effected sizes, products and applications.
RB317 - Grain: Aluminum Oxide, Coat: Closed, Weight: X, Backing: Cotton, Applications: Grinding and cleaning welds; cleaning, smoothing and polishing ferrous and non-ferrous metal parts and components.
AOGB - Grain: Aluminum Oxide, Coat: Open, Weight: J, Backing: Cotton, Applications: Sanding and fine finishing wood as well as ferrous metals where extra fine finish and/or flexibility are required.

General Purpose Materials
SPC - Grain: Aluminum Oxide, Coat: Closed, Weight: X, Backing: Cotton, Applications: Grinding and finishing ferrous and non-ferrous metals as well as sanding hard woods where loading is not a problem and durability is not critical.
SPO - Grain: Aluminum Oxide, Coat: Open, Weight: X, Backing: Cotton, Applications: Open-coat version of commodity-quality material suitable for ferrous and non-ferrous metal finishing and wood applications where loading is a consideration.
B317 - Grain: Aluminum Oxide, Coat: Open, Weight: F, Backing: Paper, Applications: Heavy weight paper provides sufficient tensile strength for finishing applications that do not require heavy stock removal yet do require fine finishes. Under-utilized but excellent on metals and woods.

Belt Joint Information
The following is a partial listing of belt joints available. Special applications at times require special belt joints, and if you know the type of joint you need, you can provide this information in the "Additional Notes" line for any line item you order.

TYPE 4 Overlap joint without top skive. Strongest joining method. One directional. TYPE 4R Overlap joint with top skive to reduce joint thickness at lap. One directional. Standard on most cloth belts 80 grit and coarser.
TYPE 5 Strong butt joint without top skive. Bi-directional. TYPE 5R Strong butt joint with relief skive. Developed for smooth platen passage. Standard on most cloth belts 100 grit and finer. Bi-directional.
TYPE 5Z Strong Z-lock butt joint without top skive. Bi-directional. Available on most belts over 12" wide, 100 grit and finer. TYPE 3 Thin mylar butt joint for wide (9" thru 37") paper belts 100 grit and finer.