![Diamond blade very macro](https://upload.wikimedia.org/wikipedia/commons/a/a3/Diamond_blade_very_macro.jpg)
A diamond blade is a
saw
A saw is a tool consisting of a tough blade, wire, or chain with a hard toothed edge. It is used to cut through material, very often wood, though sometimes metal or stone. The cut is made by placing the toothed edge against the material and mov ...
blade which has
diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of car ...
s fixed on its edge for cutting hard or
abrasive
An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away by friction. While finishing a material often means polishing it to gain a smooth, reflec ...
materials. There are many types of diamond blade, and they have many uses, including cutting stone, concrete, asphalt, bricks,
coal ball
A coal ball is a type of concretion, varying in shape from an imperfect sphere to a flat-lying, irregular slab. Coal balls were formed in Carboniferous Period swamps and mires, when peat was prevented from being turned into coal by the high am ...
s, glass, and ceramics in the
construction industry; cutting
semiconductor
A semiconductor is a material which has an electrical resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glas ...
materials in the
semiconductor industry
The semiconductor industry is the aggregate of companies engaged in the design and fabrication of semiconductors and semiconductor devices, such as transistors and integrated circuits. It formed around 1960, once the fabrication of semiconduct ...
; and cutting
gemstone
A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, ...
s, including diamonds, in the gem industry.
Types
Diamond blades are available in different shapes:
* ''
Circular
Circular may refer to:
* The shape of a circle
* ''Circular'' (album), a 2006 album by Spanish singer Vega
* Circular letter (disambiguation)
** Flyer (pamphlet), a form of advertisement
* Circular reasoning, a type of logical fallacy
* Circula ...
diamond saw blades'' are the most widely used type of diamond blade.
* A ''diamond
gang saw blade'' is a long steel plate with
diamond segment Diamond segment are the functional parts of a metal-bonded diamond tool. The metal-bonded diamond tool can be a metal-bonded diamond blade, a diamond grinding cup wheel, a diamond core drill bit, a diamond gang saw blade, etc. The diamonds of a me ...
s welded onto it. Normally, tens or hundreds of diamond gang saw blades are used together to saw raw stone blocks.
* A ''diamond
band saw
A bandsaw (also written band saw) is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and l ...
blade'' is a flexible closed steel band with diamonds fixed (often by
electroplating
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ...
) on one edge of the band.
Diamond blades designed for specific uses include marble, granite, concrete, asphalt, masonry, and gem-cutting blades. General purpose blades are also available.
Manufacturing methods
Electroplating
Blades using diamonds embedded in a metal coating, typically of
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
electroplated
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be ...
onto a steel blade base, can be made to be very thin—blades can be tens of
micrometres
The micrometre (American and British English spelling differences#-re, -er, international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American and British English spelling differences# ...
thick, for use in precise cuttings.
Vacuum brazing
Vacuum brazed diamond saw blades are manufactured by brazing
synthetic diamond
Lab-grown diamond (LGD; also called laboratory-grown, laboratory-created, man-made, artisan-created, artificial, synthetic, or cultured diamond) is diamond that is produced in a controlled technological process (in contrast to naturally formed ...
particles to the outside edge of the circular saw blade in a
vacuum brazing furnace. All of the diamond particles are fully exposed and fastened on the exterior cutting edge of the blade instead of being embedded within a metal-diamond mixture. Depending on the manufacturer's recommended blade application, vacuum brazed blades will cut a wide variety of material including
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
,
masonry
Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building ...
,
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
, various
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
s,
plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...
,
tile
Tiles are usually thin, square or rectangular coverings manufactured from hard-wearing material such as ceramic, stone, metal, baked clay, or even glass. They are generally fixed in place in an array to cover roofs, floors, walls, edges, or o ...
,
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...
and
glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...
.
Finer synthetic diamond grits will reduce the chipping of tile and burring of steel and provide a smoother finish. Larger diamond grits will provide a higher cutting speed, but will be more likely to cause chipping, burring, or cracking. Fire departments sometimes use vacuum brazed saw blades and require blades to be made with a very large diamond grit, to tear through material quickly. An intermediate grit size is used by the production industry.
Sintering
Sintered metal-bonded diamond blades are the most common type of blade. These blades consist of a
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
core (the base is steel plate, unlike that of the wires used in
diamond wire saws) and ''
diamond segment Diamond segment are the functional parts of a metal-bonded diamond tool. The metal-bonded diamond tool can be a metal-bonded diamond blade, a diamond grinding cup wheel, a diamond core drill bit, a diamond gang saw blade, etc. The diamonds of a me ...
s'', which are made by combining synthetic diamond crystals with metal powder and then
sintering
Clinker nodules produced by sintering
Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction.
Sintering happens as part of a manufacturing ...
them. The diamond segments are also known as the "cutting teeth" of the blade.
The steel core can vary in design. Some cores have spaces (known as gullets) between segments to provide cooling and
slurry removal, while others have a single continuous rim for smoother cutting. The type of core that can be used depends on the type of materials that the diamond blade is designed to cut.
Generally, there are three types of sintered metal-bonded diamond blades according to their manufacturing methods: wholly sintered diamond blades, silver brazed diamond blades and laser welded diamond blades.
A wholly sintered diamond blade is made by putting the steel core, together with the diamonds and the metal bond materials, into a mold and then sintering it in a sintering furnace equipment. Consequently, the diameter of wholly sintered diamond blades is not very large, normally not more than . Because it is participating in the sintering process, the steel core cannot be quenched, so the hardness and strength of the core are not very high. This means that these types of diamond blade may deform in high-load and high-intensity cutting processes and can exhibit low cutting efficiency.
Silver brazed and laser welded diamond blades do not have this weakness because their diamond segments and steel core are treated separately. The steel core can be quenched and processed with other heat treatments, so its hardness and strength can be high, meaning that the blade can be used in high-load and high-intensity cutting processes with high cutting efficiency and a smaller degree of deformation.
Silver brazed diamond blades' diamond segments are brazed to the steel core using a silver solder. These blades can only be used in wet cuttings. If they are used in dry cuttings, the silver solder may melt and the segments can break from the steel core and become a serious safety hazard. A laser melts and combines the metal of the diamond segment and the steel core creating a stronger weld, which can hold the segments even in high temperatures, meaning that laser welded diamond blades can be used to cut many types of stone without water cooling. However, when cutting very hard or abrasive materials, e.g., concrete containing reinforcing rebar, laser welded diamond blades should also be used with adequate water. Otherwise, it is possible for the diamond segment itself to break or the steel core below the segment to wear and break, creating serious safety hazards.
Application of sintered metal-bonded diamond blades
A diamond blade grinds, rather than cuts, through material. Blades typically have rectangular teeth (segments) which contain diamond crystals embedded throughout the segment for
grinding
Grind is the cross-sectional shape of a blade.
Grind, grinds, or grinding may also refer to:
Grinding action
* Grinding (abrasive cutting), a method of crafting
* Grinding (dance), suggestive club dancing
* Grinding (video gaming), repetitive and ...
through very hard materials.
The ''bond'' is a term used for the softness or hardness of the powder metal being used to form the segments. The powdered metals hold the diamonds in place. The bond controls the rate at which the diamond segments wear down allowing new diamonds to become exposed at the surface to continue grinding with a "sharp" edge. An important step in choosing a blade is to match the bond to the specific material to be cut. Additional factors to consider are the type and power of the equipment to be used and the availability of water. Harder materials need a softer bonded segment to allow for continuous diamond exposure. Softer materials like
asphalt
Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term a ...
or freshly poured
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
can use a harder segment to resist the increased wear that softer, abrasive materials create. In addition, the diamonds' grit (size), toughness, and concentration should also match the nature of the material to be sawed. For example, when hard materials are cut, the diamonds should be smaller.
There are other factors that should be considered when choosing a diamond blade for a particular application. These include the type (manufacturing method) of the blade, the availability of water in the cutting process, the horsepower of the saw, and the acceptable level of noise created by the saw. For example, if the horsepower of a saw machine is large, the diamond concentration of the diamond blade should be higher, or the bond should be harder. Higher diamond concentration will decrease the impact on each single diamond in working, while a harder bond will hold the diamonds more firmly.
Cutting with or without water
Many blades are designed to operate either wet or dry. However, diamond tools and blades work better when wet, and dry cutting should be limited to situations in which water cannot or should not be used. Water will prevent the blade from overheating, greatly reduce the amount of harmful dust created by cutting, remove the slurry from the cut, and extend the life of the blade, since diamond is unable to withstand the forces involved at the elevated temperatures involved in dry cutting ceramic and abrasive materials, and will be subject to rapid tool wear and possible failure.
When water cannot be used (in, for example, electrical saws), measures should be taken to ensure that the operator does not inhale the dust created by the process, which can cause
silicosis, a serious lung disease. When dry cutting, the blade should be allowed to cool off periodically. Cooling can be increased by allowing the blade to spin freely out of the cut. The
OSHA
OSHA or Osha may refer to:
Work
* Occupational Safety and Health Administration, a federal agency of the United States that regulates workplace safety and health
* Occupational Safety and Health Act (United States) of 1970, a federal law in the Un ...
has strict regulations regarding silica dust and requires a N95 NIOSH-approved respirator in work sites where dangerous amounts of silica dust are present.
References
Sources
{{Stonemasonry
Saws