120 Grit 9-in. Sanding Disc

9-in. Aluminum Oxide Pressure Sensitive Adhesive Sanding Disc - QTY:5

Production Shops Take Note - No cheap materials used here!

Our PSA (pressure sensitive adhesive) discs are made of full resin-bonded aluminum oxide, heavy cloth-backed material, along with an adhesive that holds fast yet does not gum up your backing pad. Ideal for production situations that require discs to hold fast at high speeds and for repetitious, single-grit sanding of flat surfaces. Our competitors often use inferior materials or scrap in the manufacture of their discs. KLINGSPOR provides only high-quality industrial products. The broader grit range allows you to achieve the perfect finish every time. Each pre-glued disc attaches in seconds; peel off the backing paper, stick it on, and sand.

These discs are manufactured from our premium Aluminum Oxide material for wood sanding operations where clogging or loading is a problem. Also great for sanding of soft metals such as brass or bronze.

Specifications:

• Grit-120
• Diameter 9-in.
• Material Aluminum Oxide
• Attachment PSA Adhesive

Applications

• Wood sanding
• Metal finishing
• Paint removal

Aluminum Oxide (AO)

AO is formed by combining bauxite and other materials by firing them in an electric furnace. The resultant mass is then crushed, and the pieces sifted through successively finer screens to assign a grit size (CAMI grading). When crushed, the resulting pieces are naturally pyramidal in shape. Due to the shape and the strength of the materials used in its making, AO is a very durable grain. The grain is worn down during use, sanding finer the longer it's used.

AO is very tough and durable, as stated above, and is used on bare wood, most metals (especially the steels), leather, and a wide variety of other materials. It is a great general-purpose grain and probably the most common grain seen today.

Silicon Carbide (SC)

SC is made by combining pure white silica sand and coke, a by-product of coal production. Again, these materials are combined by melting in an electric furnace, crushing the results, and sifting the particles through screens to get grit grading. SC grains are shaped like icicles with extremely sharp points and narrow grain bodies. It is second only to diamond in hardness; however, it is very brittle due to the narrow grain body. Therefore, when pressure is applied to the tip of this grain, it fractures. This characteristic is referred to as "friability". The benefit of friability is that a sharp edge is always against your workpiece, providing extremely consistent finishing ability. Because of the lack of grain body strength, which allows this grain to fracture with hand pressure only, the life span is shorter compared to AO or the other grains. Therefore, when you see SC, it's normally in finishing type operations where the pressure required for working is lower than it would be in removal grits. Examples of materials normally sanded or ground with SC would include glass, plastic, rubber, paint, varnish, lacquer & sealers. It may occasionally be seen in sanding on extremely soft woods like Ponderosa Pine, but we would recommend open coat AO instead, as the life would be much better.

Cloth Backing

There are 3 basic weights of cloth backings: J, X, and Y. J and X are cotton materials. The J has a slight degree of conformability to it and should be used where a small degree of conformability to the workpiece is needed in belts or sheets. The X is a heavier-weight cotton and is an all-purpose/general-purpose backing used in a wide variety of belting applications, including portable belts, intermediate belts, and wide belts. Y backings are 100% polyester (or in some cases a 60/40 poly/cotton split) and are used for flat, heavy-duty dimensioning or other high-heat or rough applications. The J and X weight backings have flexed versions available that are referred to as J-Flex (JF) and X-Flex (XF). These would be suitable for applications where the X or J is not quite flexible enough. The most common uses for JF backings are as pump sleeves and for mold sanding belts. The XF backings are used mainly for slack in belt operations. The Y backings are not flexed but come in a lightweight poly (YX) and a heavyweight poly (Y or YY). Normally, 24-50 or 60 grits will be the heavier poly backing, and the 80-120 will be the lighter poly backing.

Semi Open / Open Coat

The terms semi-open and open coat mean that, to different degrees, the amount of abrasive grain on the backing of your belt, sheet, or disc has been modified (lessened). Semi-open coat usually refers to a 30% reduction in the amount of grain on the backing, while open coat usually means 50% has been withheld. Thinking about these statements logically, two things can be deduced from them:

  1.) semi-open and open coat products will cut less aggressively

  2.) semi-open and open coat products will finish coarser per grit than closed coat products.

Semi-open and Open coat products have less grain on the backing, which results in less cutting power per grit designation.

Semi-open and Open coat products have gaps in their grain coverage, so the finishes they provide will not be as even and will fall to the coarse end of the designated grit's finishing parameters.