Each Cratex size and shape is made in four standard Grit Textures or compositions which differ in accordance with the mesh size of the abrasive grain used. [C] COARSE (Green) [M] MEDIUM (Dark Brown) [F] FINE [XF] EXTRA FINE (Reddish Brown) (Gray Green)
Cratex Standard Bond:
The Cratex bond common to each of the four Grit Textures is made with premium grade oil-resistant chemical rubber. In contrast to conventional grinding wheels the Cratex bond has unique cushioned action...cuts freely, smoothly and softly without gouging or digging into the work surface. It resists clogging or smearing, and is ideal for a broad range of applications where metallic or non-metallic surfaces must be smoothed and polished without loss of dimensional tolerances or control.
Cratex Hard Bond:
The Cratex Hard Bond increases the cutting action when compared to the Cratex standard bond and is designed for use only in specialized applications. The Hard Bond removes burrs on hard metals like stainless steel and can also be used for light grinding on applications where light metal removal is essential. All Cratex Flexible Abrasive Finishers, in each of the four grit textures are available in Hard Bond. Hard Bond is not available in Kits and minimum quantities are required.
Cratex Abrasive Type:
The abrasive type used in Cratex Rubberized Abrasives is premium-quality Silicon Carbide that has been washed, dried and treated to remove impurities and then carefully screened to U.S. Department of Commerce standards for size. Although silicon carbide is more expensive than other abrasive materials, it is used because it has a high level of purity and has been found to be best for the broadest range of light deburring, smoothing, cleaning and polishing applications on ferrous and non-ferrous alloys as well as many non-metallics, such as glass.
Shapes and Sizes:
The Cratex Wheels, Points, Cones, Blocks and Sticks listed in this Catalog are all available as standard products. The occasional need for non-catalog shapes or compositions can usually be solved by adapting or modifying standard shapes and compositions to meet special requirements. Several wheels can be mounted in series for added width. The abrasive action of the wheels can be softened by using lower operating speeds and lighter work pressures. Cratex Rubber Bonded Abrasives can also be dressed or shaped to special contours using conventional abrasive wheel dressing tools and methods. Contact a Customer Service Representative for further information.
All Cratex Rubberized Abrasives are made and safety inspected to the requirements of American National Standards Institute (ANSI) publication, B7.1 Safety requirements for the use, care and protection of abrasive wheels. This publication should be made available to all operators of Cratex products. Copies of this publication are available from: Grinding Wheel Institute, 30200 Detroit Road Cleveland, Ohio 44145 or American National Standards Institute, 1430 Broadway New York, New York 10018
When Ordering: Specify the part number and grit texture. (C) Coarse, (M) Medium, (F) Fine, (XF) Extra Fine. For Example: 54-C. Certain products are sold in units of 1 and others in boxes of 100. Refer to the Cratex Industrial Price List to verify the correct unit when ordering.
LIGHT DEBURRING and smoothing to relieve stress concentrations and to remove visible and microscopic burrs without impacting surrounding areas.
SMOOTHING and polishing to improve wearing qualities and to reduce the dangers of progressive fracture and fatigue failure.
CLEANING and polishing to remove undesirable surface deposits.
POLISHING and smoothing to improve performance, appearance, cleanliness and to lessen the dangers of surface contamination.
Typical Applications Include:
Breaking edges, radiusing and polishing out high spots, removing rust, cleaning threads, smoothing the edges of punched or sheared metal, deflashing, smoothing and polishing molds, dies and other production tools, sharpening and honing of cutting dies, blades and edged tools, removing corrosion, excess solder, heat marks, cleaning and polishing contact points, jacks and electrodes, removing tool marks, scratches, light burrs, and fins, blending in welded seams after rough grinding, engine turning, damaskeening, polishing engine ports, shafts, turbine blades, smoothing glass edges, jewelry finishing, gem stone sanding and many others. Cratex Rubber-bonded Abrasives are used in a widely diversified list of industries, on production and assembly lines, in finishing operations, in tool and machine shops, in the production of basic tools, instruments, component parts and for maintenance and repairs.
Cratex Rubberized Abrasives are carefully manufactured, tested and inspected. Nevertheless, as with all abrasive products, they must be used properly and in accordance with established safety codes. ANSI B7.1, as mentioned on the second page of this catalog, is mandatory reading for all grinding wheel users!
MOUNTING: The area of greatest stress in abrasive wheels is at the center hole. Wheels should therefore be mounted on spindles or arbors of correct diameter (nominal diameter plus zero minus .002 inches). Avoid forcing the wheel onto the spindle. Proper fit, neither too tight or too loose, is essential.
Cratex Wheels shall be mounted only on straight spindles (not tapered) and shall be supported by standard abrasive wheel flanges of equal size covering at least 30% of the wheel diameter. The back flange should be keyed or secured to the shaft (except when mounted on a mandrel) and the outside flange nut should be tightened only enough to keep the wheel from slipping while it is in use. Several Cratex Wheels can be mounted in series for additional width, providing the mounting spindle is large enough to support the extra weight.
PROTECTIVE GUARDS AND SHIELDS: When operating an abrasive wheel, the operator should be properly shielded. The operator as well as any other personnel in the work area should wear safety goggles and face shields.
WHEEL DRESSING: The same dressing and truing tools and methods are used on Cratex products as are used on conventional grinding wheels. Cratex Dressing Blocks are ideal as are all types of manual or mechanical dressers and diamond truing tools. Truing achieves a concentric geometry between the periphery of the wheel and the spindle on which the wheel is mounted. Dressing is a cleaning operation. It clears the wheel face and exposes fresh, sharp-cutting abrasive grains. Procedure: The dresser or turning tool should be supported on a work-rest (set not more than 1/8 inch away from the wheel face) and held at a slight (5 to 20 degree) angle to the wheel face. Light cuts should then be taken in a straight line across the high points of the wheel until the face is smooth and even. The wheel must not be run at full speed until any signs of imbalance have been removed.
After the wheel has been trued or shaped it should be permitted to turn at full speed (not to exceed maximum safe speed) for one minute or more before work is applied. During this time the operator should stand to one side, away from the wheel.