Bonded Abrasives
Coated Abrasives
Rice Polishing
Investment Casting
High Abrasion Resistance Coating
Micro-Porous Insulation
Thermal Spray
Brake Lining
Dental Blasting
Wire Sawing

Bonded Abrasives

Bonded Abrasives

Bonded abrasives is a matrix of closed size abrasive grains pressed or moulded together with the help of vitrified, resinoid or rubber bonding material into a variety of shapes, like grinding wheel, honing stone etc. The matrix is fired at high temperature to provide a high strength bonding between the abrasive grains.

CUMI specialize in manufacturing of a complete line of closed sized abrasive grains in various shapes, sizes and densities, etc. to perfectly fit any grinding application and working condition.

CUMI Sharp grains are blocky sharp edges with low iron and silica content. Its high toughness & hardness (Mohs Hardness 9), excellent abrasion resistance, high corrosion resistance properties combined with cooler cutting characteristics, appropriate friability, multi-fracturing properties exposing sharp edges and self sharpening characteristics makes it an ideal raw material for the manufacturing of bonded abrasive for all applications.

Typical Applications

Range of Products
  • Ball grinding & ball lapping wheel
  • Rice polishing wheel
  • Gear grinding wheel
  • Cam grinding wheel
  • Crankshaft grinding wheel
  • Valve components grinding
  • Internal grinding wheel
  • Thin wheel
  • Tool room grinding wheel
  • Roll grinding wheel
  • Mounted pins
  • Centreless grinding wheel
  • Razor blade
  • Flute grinding
  • Bearing grinding wheel

Coated Abrasives

Coated Abrasives

Coated abrasives is a three component system consisting of abrasive grains adhering to the semi-flex backing like paper, cloth, fibre, plastic film etc with the help of resin or glue bond.

Coated Abrasive is manufactured as rolls which is then converted into different foams like belts, disc, flap disc, flap wheel & spindle mop, sheet & non- woven products.

CUMI specialize in manufacturing of a complete line of closed sized abrasive grains in various shapes, sizes and densities, etc. to perfectly fit any coated abrasive application and working condition.

Sharp Grains for Coated Abrasives

CUMI Sharp Grains for coated abrasives are angular, sharp edged with high capillarity for instant adhesion to resin or glue bonds and electrostatic characteristics carefully monitored to provide consistent and reliable grain projection. The High hardness (mohs hardness 9) and toughness of the CUMI Sharp grains combined with the multi-fracturing property , self sharpening characteristics and cooler cutting characteristics of the grains makes it an ideal raw material for the manufacturing of coated abrasives for any application.

Typical Applications

Coated abrasives are used by hand or on machines, applications are extremely varied, at home and in industry for:

Fine finishes: hand sanding or polishing of wooden cabinets, car bodies primers, metals.

Coated Abrasive Applications

High precision operations: Optical lens polishing, magnetic head super-finishing.

Medium stock removal with portable or fixed machines: Floor sanding, disc grinding of metal, endless belts grinding of wood, metal, glass.

Heavy stock removal with wide (up to 3 m) belts on high power machines to grind stainless steel sheets or coils or to calibrate plywood or chipboard panels.


Super Refractories

A Refractory is a material which can withstand high temperature and at the same time retains its structure and are physically & chemically stable. Fused minerals due to their ability to withstand high temperature along with high resistance to corrosion, abrasion & impact , is used for the manufacturing of Refractories material (fired & monolithic) owing to the fact that Refractories materials are in continuous exposure to the combination of heat, corrosion, abrasion and impact under working condition.

Heat Fused Minerals

Cumi Heat fused minerals grains possesses high purity with uniform composition and are chemically & physically stable at high temperature. Also its high resistance to corrosion and chemical attack, low thermal expansion, high strength to withstand aggressive abrasion & impact, high thermal shock resistance and adequate thermal conductivity makes it an ideal raw material for the manufacturing of refractories (fired & monolithic).

Typical Applications

  • Lining of Furnace, Kiln, Incinerators, Reactors for metal, ceramic, cement and chemical & petrochemical, glass, carbon black industries.
  • Manufacture of crucibles
  • Kiln furniture
  • Ceramic Filter for metal purification
  • Tap hole mass
  • Ramming mass


Metallurgical Industries uses Silicon Carbide

Iron & Steel melting and casting industries usually referred as metallurgical industries uses Silicon carbide in the form of briquette or pellets or granule as a alloying agent for silicon & carbon or as reducing agent for the removal of excess oxygen.

CUMI-met is a special grade of metallurgical silicon carbide with 88% purity with very low sulphur & nitrogen content in the form of pellets is a prime source of silicon and carbon to the melt. It also improves the inoculating action thereby refining the distribution of graphite flakes or spheroidal graphite in the micro-structure offering more number of nucleation site. Apart from that, it removes the excess oxygen in the melt thereby reducing the pin hole porosity of the casting, improving the life of the furnace wall and by the exothermic nature of the oxidation reaction provides extra fluidity to the melt. These characteristics of CUMI-met makes it an ideal alloying agent and reducing agent for metallurgical operation.


Typical Applications

  • Automotive, pump & other industrial components made of S.G. Iron or gray iron.
  • As reducing agent in steel plants.


Abrasive blasting is an mechanical operation of cleaning or preparing a surface by forcibly propelling a stream of abrasive material on the surface using a compressed gas (typically air) or pressurized liquid (typically water) as a propellant. Abrasive grains used for the blasting operation ranges from coarse grits to micron sized particle depending upon the operation and desired results.

CUMI specialize in manufacturing of a complete line of closed sized abrasive grains in various shapes, sizes and densities, etc. to perfectly fit any blasting operation and working condition.

CUMI Sharp range of abrasive grains due to it high hardness, toughness and strength combined with sharp edged grains, self sharpening characteristics and high resistant to mechanical wear and tear increases the mechanical effciency to surface cleaning and surface preparation and increases the recyclability of the grains thereby reducing the dust generation during dry blasting to minimal. These characteristics of the CUMI sharp grains along with its excellent chemical inertness makes it an ideal blasting media for all blasting operations.

Typical Application

  • Valves casing cleaning
  • Foundry industry for cleaning of casting.
  • Textile industry for machine part finishing before plasma coating
  • Cleansing of instrumental coating.
  • Surface preparation before electroplating
  • Cleaning of automotive part before painting
  • Etching surface before metal spraying
  • Production of opaque glasses
  • Pressure blasting of granites and marble for engraving purpose.
  • Turbine blade blasting
  • Nonstick cookware blasting prior to teflon coating
  • For Heat treatment casting.

Rice Polishing

Rice Polishing

Production of white rice involves the milling of the rice seed to remove the chaff which produces brown rice, followed by further finishing to remove the bran i.e. the rest of husk, thereby producing white rice. The milling is done is a roller machine which consists of revolving cylindrical stone coated with a paste of abrasive mineral and sorel cement (Mg(OH)2 and MgCl2) in a proportionate amount of water.

The brown rice is polished by the rubbing action between the abrasive roller and the leather pad. The finished rice can be recycled into the process depending upon the desired quality of the rice.

Sharp Grains
Production of White rice

CUMI Sharp grains are possesses high purity, which do not contaminate the rice, along with the high strength, high hardness and excellent wear resistance which provides uniform polishing of the rice,lower cycle time/ processing time and better life to the paste on the rolling stone.

Investment Casting

Investment casting or lost-wax casting process is used for the manufacturing of net shape metal alloy components. Highly complex and critical components are manufactured to net shape by this process. The metal alloys may be ferrous, non-ferrous or super-alloys depending upon the criticality of the component application. The manufacturing process of the net shape components through investment casting involves the following steps.

Wax Injection Wax Tree Ceramic Shell Building Dewaxing Pouring
Wax Injection Wax Tree Ceramic Shell Building Dewaxing Pouringg 
Knoskoutg Cut-off Finishing    
Knockoutg Cut-off Finishing    

CUMI Sharp White fused alumina grains are used in the shell building and the metal finishing part of the investment cast process.

The high temperature withstanding capability under load of CUMI sharp white fused alumina combined with a very low thermal expansion co-efficient, excellent thermal shock resistant, high chemical inertness, high slag resistant, and non-wettability characteristic of white fused alumina to metal alloys makes it an ideal material for shell building for investment casting.

Typical Applications

White Fused Alumina
  • Aerospace components
  • Complex automotive components
  • Valves and pumps parts
  • Industrial machinery components
  • Scientific components
  • Medical components


Anti -skid surfaces are used extensively in the high traffic area for industrial flooring and ship deck to provide traction and slip resistant. The anti-skid surface should be able to withstand heavy wear & stress and should be inert toward chemicals thereby reducing protecting the floor from wear & tear and chemical attack. The anti-skid surface for the industrial flooring and ship deck are usually made from a resin e.g. epoxy, PU etc mixed with a proportionate quantity of abrasive particles or filled on the concrete which provides the necessary friction to the traffic.

Anti slip surfaces in the form of tapes with abrasive particles embedded on it are also used in the house hold and highway / road to provide necessary friction to the traffic. Also anti-skid tiles are embedded with abrasive grains to provide in the necessary slid/skid in the high traffic area.

CUMI Sharp fused abrasive grains due to its high strength & toughness and high corrosion resistant provides high friction retarding slip/skid and makes it an ideal abrasive material for the manufacturing of anti-skid/anti-slip surface or tapes.

Typical Applications

  • Anti-skid tape on the stairs at home
  • Anti-skid tapes in bus
  • Anti-skid tapes on road at zebra crossing
  • Industrial Flooring
  • Ship deck
  • Anti-skid tiles for high traffic area in office or homes



Laminates made up of synthetic resin material or synthetic materials combined with natural and recycled ingredients, used for the flooring are made to look like natural products such as wood flooring or natural stone. Laminate flooring has a dense inner core and a layer glued on it. The decorative finishing to the laminate is provided by careful polishing of the outer layer by white fused alumina.

CUMI Sharp micro grains due to it high purity which do not contaminate the surface along with precise size distribution, high strength & toughness and good friability at micro level removes the stock from the surface while polishing thereby providing a laminate surface with uniform & very low surface roughness and excellent finish. These characteristics of CUMI Sharp micro white fused alumina makes it an ideal finishing material for floor laminates.

High Abrasion Resistance Coating
  • Flooring at home and work
  • Tabletops
  • Countertops

High Abrasion Resistance Coating

High abrasion resistance coating is a composite system containing a high strength resin like epoxy and high abrasion resistance ceramic particles. The high abrasion resistance coating is in the form of a thixotropic paste which could be easily applied on the surface with a brush or in the form of a putty containing upto 70% solid mass. The high abrasion resistance coating is used as a protective coating or to repair worn areas in material handling equipment or components conveying abrasive materials.

CUMI Sharp micro grains possesses high hardness (more than 9 Mohs), high toughness, excellent abrasion resistance, high resistance to chemical attack and corrosion. These characteristics of CUMI sharp grains makes it an ideal raw material for the manufacturing of High abrasion resistance coating.

Typical Applications

Abrasive Materials
  • Slurry transport Lines
  • Agitator assemblies
  • Impellors
  • Ash and slurry Pumps
  • Shafts
  • Exhaust fans
  • Ore processing tanks
  • Screw conveyors
  • Cyclones
  • Pipe elbows
  • Reducers
  • Pulverisers etc.

Micro-Porous Insulation

Micro-porous insulation is the advanced insulation technology which exhibits superior insulation characteristics. It is used in the application where the largest temperature drop is required through the thinnest possible cross-section with the lowest possible mass. The micro-porous insulation is highly porous and is mainly composed of inorganic oxide, primarily fumed silica (Approx - 75-80 %) micro sized particle and micro sized opacifier (Approx - 15-20%).

Micro-porous insulation has the thermal conductivity lower than the still air in the range of 0.02 -0.04 W/mK at 200-800 0 C. The performance of the micro-porous insulation is based on the the ability of micro-porous insulation to block the three modes of heat transfer - Conduction, Convection and Radiation.

The conduction heat transfer is reduced due to the very high porosity and low density of the micro-porous insulation. The size of the voids in the structure is smaller than the mean free path of the air molecule which reduces the convection heat transfer. And billions of micron sized opacifier particles distributed homogeneously in the silica matrix absorbs the radiant heat at high temperature and re-radiate or distributes the heat back to the system thereby reducing the heat loss due to radiation.

CUMI offers micron sized silicon carbide particles in the size range of 2-5 microns which possesses high thermal conductivity with high emissivity which produces an excellent infrared radiation absorption and re-radiation characteristics. These characteristics of our micron silicon carbide makes it an ideal opacifier.

Typical Applications

Micro Porous Insulation
  • Vacuum Insulation panel which is used for house insulation
  • Radiant heater insulation
  • Fire protection equipment.
  • Back up insulation in high temperature furnaces - Steel, Glass, Ceramic, Aluminum.
  • Aluminum Launders
  • Transfer ladle, Torpendo ladle and Tundish insulation.
  • Chimney and pipe insulation

Thermal Spray

Thermal Spary

Thermal spray coating consists of powers (ceramic, metallic, inter metallic) of specific grain size which are heated to its melting point by means of the high temperature arc and propelled to the surface of the work piece by means of a gas thereby creating a uniform coating on the substrate.

Thermal Spray coating enhances, protects and alter the surface properties of components thereby creating thermal barriers, wear resistance, chemical resistance ,corrosion resistance or electrical enhancement coating.

CUMI offers a variety of high quality thermal spray coating based on alumina, titania and chromia for various applications.

Typical Applications

  • Textile machine parts
  • Electronic components
  • Automotive sub assemblies
  • Medical instruments
  • Jet engines etc

Brake Lining

Brake lining are mainly composed of a heat resistant and strong fiber which are relatively soft yet tough with high co-efficient of dynamic friction mounted to a solid backing using high temperature adhesive or rivet. In order to increase the dynamic co-efficient of friction and decrease the wear of the brake lining under high temperature produced during braking, ceramic grains are added to the fiber.

CUMI Sharp micro grains with stringent particle size distribution possesses high toughness & hardness, excellent abrasion and wear resistant and physical & chemical stability at high temperature which makes it an ideal additive to the brake lining for higher dynamic co-efficient of friction, longer life and hence better performance of the brake lining.

Typical Applications

  • Automotive brake
  • Rail brakes
  • Air-craft brakes
  • Friction material for industrial machineries


Lapping is a precision machining technique used to produce flatness, parallelism, thickness or surface finishing to an extremely demanding tolerance. Lapping involves a process in which two surfaces are rubbed together with a fine abrasive grains, in the loose dry form or suspended in a liquid carrier, between then to remove the stock from a surface.

Cumi-sharp micro abrasive grains due to its high hardness and good friability at micro level along with stringent particle size distribution makes it an ideal abrasive grains for the faster and uniform removal of the stock from the surface thereby providing better surface finishes during lapping.


"A" is the work. "B" is the tool

Typical Applications

  • Auto components
  • Compressor parts
  • Pump parts
  • Advanced ceramic components
  • Optical lens
  • Optical electronics devices


CUMISHEEN is biologically treated and refined  alumina product. It is used in the cosmetic industry in products such as body and facial scrub, special creames, soaps, dermabrasion, cleansing lotions,

It is pure white in colour with high alumina content (98%-99%). Free from any contamination mainly iron. Biologically and chemically inert. The microscopic structure reveals sharp edges which will help in abrading process. It is available in various sizes but most widely used sizes are 100 or 110 microns.

Dental Blasting

Dental Blasting

Odoblastae is CUMI's unique and special form of grain manufactured in our state-of-the-art technology plant. Ideal for blasting of substrates in the preparation of teeth crowns.

Features and Benefits

  • Extremely pure and inert
  • Excellent cleaning and roughening effects
  • Remarkable surface penetration and uniformity
  • Excellent durability and a blocky crystal structure, rendering it most suitable for blasting
  • Unique potential to increase surface area
  • Prevents formation of micro-cracks in ceramic coating that might lead to crown fracture.

Wire Sawing

Wire sawing is a method for slicing and cutting silicon wafers. In wire sawing, a taut steel wire is run through an abrasive slurry of silicon carbide which acts as the cutting agent between the work piece and the wire. Wire sawing is commonly used in the silicon wafer production

CUMISLICE - Premium micro grit for slicing silicon wafers is classified to narrow customized size distributions, offers the benefits of predictable performance in wafer slicing.... lot after lot.

This product is critically designed and tailored to yield :

  • Desired wafer thickness
  • Close TTV distribution
  • Superior surface quality
  • Low kerf loss

Please click the links listed on the side to know more about the various applications

Murugappa Group