Welcome to our technical information section!
Download our "How to cut green concrete" as a zipped PDF or view it in a new window
Check out "Saw cutting joints in slabs"
Read the "PDF Diamond drilling short curved utility holes in hard rock" (PDF File)
Download our "Drilling Straight Holes" as a zipped PDF or view it in a new window
Download our "Drilling Speed Table" as a zipped PDF or view it in a new window
Download our "Safety Tips" as a zipped PDF or view it in a new window
Download our "What is the price for?" as a zipped PDF or view it in a new window
What is the price for?
Diamond saw blades cannot be easily compared by price alone.
Although price has always been an indicator of quality it may not have alot
to do with performance on the job.
The numerous interactions between material, machine, conditions, operator
and blade need to be translated into a value for budget solution, not a
price. Literally dozens of diamond specifications can be utilised by the
tool designer, and just about every metal alloy ever conceived used as a
bonding agent for them. This alone would result in a bewildering number of
possible combinations available to the tool manufacturer. Having chosen the
diamond and bond, a manufacturing method will need to be decided upon. There
are many. In the manufacturing process tolerances will have to be set;
density, porosity, and hardness values amongst others decided. Segment size,
number, and diamond weights, as well as mounting technology and steel
quality, all have their role to play. Is it any surprise that choosing a
diamond blade specification is more complicated than simply by price? The
applications engineer must consider local conditions, budgetry restrictions,
operator preference, machine condition, intended use, especially in
materials of a differing nature.
When blades are purchased by price comparison one assumes all other factors
are equal. This is simply most unlikely! Blades are about as similar as
tyres these days. Tyres are usually black. Blades are usually round. That is
where the similarity ends.
How then does a buyer decide if he is getting value for money with this
complex tool ? Perhaps this is where market place experience, reputation,
service, after sales support, technical training, support literature all
play a part. One thing is for sure if you compare only blade price and
diameter you will take the risk that the blade chosen will not carry out the
task at the envisaged cost. it may fail altogether.
Remember diamonds are available from many sources:- natural diamond and
synthetic diamond is available. It varies in price per carat according to
size, purity, toughness and quality consistency standards such as ISO 9001.
Bonding metals are available from many sources also. Metals which perform
well usually cost more to produce and supply than poor performers. Bonding
metals may need to mechanically and chemically hold the diamonds.
Diamond blades can be laser welded together, brazed, sintered or laser
formed. Laser welding plant is more costly than brazing equipment and
produces a stronger joint which is not affected by dry cutting temperatures.
Diamond blades use special steel cores. These steel cores are required to
resist stress and wear in the cutting process. Better steels hold their
tension better and support the diamond segments longer and more safely. Yes,
it is complex.
Applying diamond blades to the job is clearly an art, not a science. Try to
find the artist.
o
Download our "Blade Construction FAQ" as a zipped PDF or view it in a new window
Diamond Blademan blade construction methods and types
Q.What is a laser welded diamond blade?
A. A Diamond Blademan laser welded diamond blade is
a segmented diamond blade constructed by laser welding diamond segments to a
steel blade core.
Q.What is a brazed diamond blade?
A. Brazed or silver soldered diamond blades are segmented diamond blades
constructed by brazing diamond segments to a steel blade cores using high
silver content, low melting point brazing materials.
Q.What is a sintered diamond blade?
A. A sintered diamond blade is a diamond blade constructed by mould
furnacing diamond segments with a steel blade core to produce a one piece
unit. In effect the segments are produced as they are bonded to the steel
core of the blade.
Q.What is a lazer grown diamond blade?
A proprietory laser manufacturing technique sometimes used to create a
diamond segment at the same time as
joining it to a steel blade core.
Q.What is an electroplated diamond blade?
A. A Diamond Blademan electroplated diamond blade is
a diamond blade constructed by electroplating diamonds to a steel blade
core using nickel.
Download "Diamond Blades and Concrete Curing" as a zipped PDF or view it in a new window
Diamond Blades and Concrete Curing
Diamond blade bonds, sometimes known as matrices, are central to the diamond
blade¹s ability to self sharpen, as the diamonds wear out during cutting.
When cutting concrete, it is necessary to understand the curing process.
This assists in choosing a bond which will allow self sharpening of the
diamond blade to take place. Chosen correctly the blade will self sharpen
at the same rate as the diamond is wearing out and allow free cutting and
long life of the tool. Abrasion of the diamond blade core will be
controlled.
Newly laid concrete cures in three stages. It can be very abrasive during
the curing stages due to the inability of weak, green, and semi cured
concrete, to hold on to the sand and small pieces of aggregate whilst being
cut. The sand is pulled out of the concrete during cutting, creating an
abrasive environment. Sand with sharp edges will be most abrasive.
During stage one, somewhere in the region of 7-10 hours after pouring
depending on weather and other conditions, the concrete is considered
³green². During this early stage the concrete has not set up completely and
is often highly abrasive. The sharper the sand and aggregate the more
abrasive it is.
Stage two, approximately 10-24 hours atfer pouring , the concrete has set
up, the sand and small bits of aggregate are held more firmly and the
conditions are less abrasive.
After 24-72 hours, when the concrete is semi cured, the sand and aggregate
are quite firmly held and the abrasiveness is further reduced.
Over 72 hours, depending on the pour and weather conditions, the concrete is
considered to be cured. Abrasiveness is much less of a factor now being
replaced in importance by aggregate hardness, size, reinforcements etc.
Dimond blade bond choice is for wear resistant harder types in stage 1 and 2
concretes, usually accompanied by undercutting protectors for the steel
core of the blade. During stage 3 and later, a softer bond will give better
results, particularly with reinforcement and hard and or larger aggregates.
Joints in warehouse floors, driveways etc are usually cut during stage two.
Special diamond saws can cut very early on because of their ability to cut
with a minimum of disturbance to the green concrete.
Green concrete diamond blades by Diamond blademan allow for these
variations.
Download "Stay out of trouble diamond core drilling" as a zipped PDF or view it in a new window
Stay out of trouble diamond core drilling
Diamond core drilling reinforced concrete is both an art and a discipline,
requiring patience, structural appreciation, a mechanical aptitude, and
considerable fitness.
The basics for successful core drilling are having a rigidly set up drill
rig, diamond core bits with adequate clearances on the outside diameter and
inside diameters, constant water flow, and the right speed range and power
for the bit.
Lets consider some of the potential problem areas for the relatively
inexperienced.
Jamming of the diamond bit can be caused by about five different things.
Firstly a loose drilling machine which needs anchoring firmly to the
concrete (perhaps the vacuum pad is leak-ing or the anchor bolt is loose)
and realigning. It may be caused by mobile bits of stone or rein-forcing
steel in the hole which should be removed. Inadequate flushing of the core
creates friction and jamming as does a bent or damaged corebit.
A core jammed in the diamond core barrel is most likely caused by a broken
core of concrete. In this case the corebit will have to be removed from the
drill and the concrete core forced out of the barrel. Lack of water can
cause the concrete to expand through frictional heat and jam in the barrel.
Gently working the core free without force is a good remedy. A concrete
core which is almost identical in size to the barrel inner diameter can
cause a problem, solved only by the use of a diamond bit with adequate
internal diameter clearance.
Rapid wear of the diamond bit occurs when an unstable drilling machine is
used particularly if the drilll spindle bearings are worn and insufficient
speed is used. Drilling at a faster speed will often result in better
penetration rates and longer bit life. Try it. Excessive feed pres-sure,
insufficient water, or very abrasive material, can also reduce bit life, as
will heavy concentrations of steel reinforcement. Generally the harder the
job the bit has to do, the shorter the bit life.
Segments come off bits through being ripped off by loose material jamming
the bit in the hole, insufficient water to cool the segment fixtures,(they
melt off) vibration, hammering from a poor set up, and excessive pressure on
the bit.
Slow core drilling can be caused by a blunt bit with few exposed diamonds
(sharpen by drilling highly abrasive mate-rial, until bit is sharp, ie
diamonds feel agressive again), insufficient bit pressure, slow bit speed,
very heavy steel reinforcement, or the wrong diamond bit specification for
the material.
Download our Diamond Blade Pricing document as a zipped PDF or view it in a new window
Diamond Blade price
An increasing number of diamond blade suppliers in the world today sell
blades on price. One is led to believe that any 14²(350mm) blade for
concrete is the same as any other blade for concrete and that the only value
determinant is price. Let¹s examine this.
Diamond blades have critical components ie. Diamond, metal bonding, steel
core, segment moulding system, protective segments, assembly techniques,
design objectives and intended tool consistency.
Concretes vary in strength, aggregate hardness, aggregate size, sand and
fines, steel concentrations etc.
Diamond blade designers will need to allow for these concrete variables, as
well as machine parameters, such as the mechanical condition of the saw.
In the case of a very hard aggregate cured concrete, a diamond blade with
structurally unsound diamond will suffer from rapid wear. Low priced
diamond for blades is usually not as structurally tough as a similar sized
diamond which costs more.
Diamonds are available from many sources:- natural diamond and synthetic
diamond is available. It varies in price per carat according to size,
purity, toughness and other factors.
Bonding metals are available from many sources also. Metals which perform
well usually cost more to produce and supply than poor performers. Bonding
metals may need to mechanically and chemically hold the diamonds.
Diamond blades can be laser welded together, brazed, sintered or laser
formed. Laser welding plant is more costly than brazing equipment and
produces a stronger joint which is not affected by dry cutting temperatures.
Diamond blades use special steel cores. These steel cores are required to
resist stress and wear in the cutting process. Better steels hold their
tension better and support the diamond segments longer and more safely.
Attention to these details can produce a safer more productive diamond blade
which lowers cutting costs. The converse is also true.
Download our Aggregate Hardness tips as a zipped PDF or view it in a new window
DIAMOND BLADES AND CONCRETE AGGREGATE HARDNESS
The aggregate hardness in concrete has a major part to play in the choice of
the diamond blade bond. Hard aggregate requires a softer bond than soft
aggregate.
Diamonds blades wear faster when cutting hard aggregate concrete and slower
than when cutting a softer aggregate concrete. To keep the blade sharp, the
bond must allow fresh new diamonds to begin working, as the work worn
diamonds degrade in performance.
Rapid diamond wear in very hard aggregate concrete requires a softer bonded
diamond blade than a softer, more easily cut aggregate..
The Moh¹s scale of hardness is used to categorise concrete aggregate
hardness.
In 1822 Frederick Mohs, an Austrian mineralogist, published the classic
scale for hardness. Apparently he got the basic concept from scratch tests
used by miners. The scale has 10 minerals as standards, arranged in order
of increasing hardness( with a few extras). These are:
1 = Talc
2 = Gypsum
3 = Calcite, most Marbles
4 = Fluorite
5 = Apatite (Fluorapatite)
6 = Orthoclase ,Feldspar
7 = Quartz,high quartz granites
8 = Topaz
9 = Corundum
10 = Diamond
Rule of fingernail:
A fingernail has a hardness of 2.5,
....a cent has a hardness of about 3.5,
....glass and a steel nail about 5.5
Chert and flint, are 7-9
Quartzitic river gravels, some granites 5-7
Hard limestones, some softer granites, Dolomites, Schist, Traprock, marble 3-5
Soft limestone 2-3
View our Bonds and Matrices tips (PDF) or download the zip!
DIAMOND BLADE BONDS AND MATRICES
Diamond blade bonds, sometimes known as matrices, are central to the diamond
blade¹s performance. Many diamond blade performance secrets lie in this high
tech area.
Some diamond blade manufacturers develop their bonds in house, others buy
bonds from bond manufacturers, others use bonds under license, and some
combine all three.
To perform well, a bond needs to hold the diamond teeth for as long as they
are cutting efficiently, then let them go.
In wet cutting blades it may or may not be necessary for the bond to conduct
heat efficiently as water aids the cooling process, but in a dry cutting
diamond blade the bond must conduct heat very well. Some dry cutting bonds
do this better than others.
Diamond blade bonds designed for cutting hard materials are usually less
wear resistant than bonds designed for cutting softer, more abrasive
materials.
There is no perfect bond for all diamond cutting operations, as the cutting
operation has many factors that are interacting with each other. For the
diamond blade to be self sharpening, the bond needs to wear away as fast as
the diamonds are being worn out.
As a general rule a bond is doing it¹s job effectively when ³comet tails²
form behind the diamonds, these act as supports for the hard, but relatively
fragile, diamond teeth.
Fast cutting, shorter life blades usually rely on softer bonds for speed.
Longer life blades rely on harder more wear resistant bonds in the attempt
to get as much wear from each diamond as possible.
Better bond performance contributes to diamond blade efficiency and is
directly related to cost. Better bonds cost more, but save money in the long
run.
Using diamond blades in a general purpose fashion puts great demands on bond
and diamond selection by the diamond blade designer. In spite of best
endeavours, general purpose use will always result in varying performances
according to the many factors involved in the cutting process.
How is diamond size measured? Find out HERE!
Check out THE KNOLLS, where man-made diamonds were first produced!
DIAMOND BLADES AND THE BASICS
Download diamondblades.pdf
Diamond blades are rapidly growing in popularity with tradesmen and
hobbyists all over the world. They are a sensational tool and simply can¹t
be beaten for many tasks such as cutting concrete, asphalt, stone, tile,
glass, fibreglass, reinforced concrete, fibrecement board, cast iron pipe
and many other construction materials.
Not only do diamond blades come in all diameters for virtually any saw
imaginable, diamond blades also come in different types to achieve different
cutting rates, thicknesses of cut, etc.
The most popular type of diamond saw blade these days is the segmented
diamond blade.This tool is constructed using a steel core with slots cut in
it and diamond impregnated metal segments. The diamond blade is either known
as a brazed segmented diamond blade or laser welded segmented diamond blade.
Gaining in popularity with users of small hand tools such as circular saws,
power cut off saws, tile saws, brick saws, drop saws grinders etc is the
turbo or serrated diamond saw blade.
There are other types of diamond blades with continuous cutting rims, either
electroplated with diamond or impregnated with diamond.
Hybrids of these basic types are also available for example the serrated
segmented
diamond blade which is a kind of combination of two popular blades and is
popular
on small saws.
Usually one of the first questions you will be asked when buying a diamond
blade is-
³what do you want to cut?² It is important to specify a suitable type of
blade for the material in question because the bond that retains the diamond
cutting teeth is matched to the cutting operation. It is very important.
Knowing what the diamond blade has to cut is one thing, but the engineer
also needs a clear idea about the entire operation. The reason for this is
that the diamond blade is usually a self sharpening tool and must therefore
closely match the sawing task or it will become blunt or wear too quickly.
A hard to cut material usually requires a softer bond than an easy to cut
material. This is because diamond wear will be higher per linear metre cut
in hard materials due to the tougher work the diamond teeth have to do. The
bond is made softer to allow the tool to self sharpen quicker.
Diamond blades vary in price too. Diamond teeth are actually carefully
engineered factory manufactured synthetic diamonds. They can be large,
medium, small, or very small; super tough, tough, medium tough, etc. The
bigger and tougher the diamond, the higher the price. General Electric is a
world leader in this technology.
Prior to laser welding, and the invention of the dry cutting turbo blade,
diamond blades were usually segmented and brazed together with silver solder
at about 700 degrees centigrade. This temperature could not be exceeded or
the blade would self destruct.
For this reason diamond blades were usually cooled with water.
Laser welded diamond saw blades allowed much higher temperatures to be
reached
without the segment joints being compromised, and so offerred an opportunity
to cut dry
when heat conducting low friction bonds were used.They are usually tougher
blades.
Although diamond blades can be used without water, air has a limited
capacity to cool and this must be considered by the operator. Cutting within
the blade¹s capacity to dissipate heat is achieved by keeping the blade
sharp and not allowing it to build up heat. Practically, this is done by
cutting at no more than about 75% of the blade¹s maximum rate of cut.
Frequent cooling off periods may also be made part of the operation to
reduce the temperature.
Like most wearing parts, and diamond blades are no different, they will last
longer when kept cool. Using water as a coolant, whenever possible, will
return lower costs. It is a little known fact that many dry cutting diamond
bladees cut about 10% faster than their water cooled cousins.
Having discussed the proposed diamond sawing job with the engineer it will
also be necessary to consider how clean the cut will need to be. The best
cut finish is usually achieved with continuous rim diamond blades and these
are particularly popular with glazed tiles and other easily chipped
materials.
Remember the choice of diamond blade depends on many factors;- price and
performance needs, durability and safety considerations, machine condition,
materials to be cut,
and operator experience. When these factors are understood, a wise
satisfying choice is likely to be made.
Diamond blades are here to stay and represent amazing value for money. It is
difficult to imagine how we got along without them. Probably there was a
lot more noise and dust.
Download Andrew's Speed Chart (PDF format)
Sawing brick with diamond blades
Sawing bricks with diamond saw blades is accurate, productive, and provides
a quality job. Customers like the results . These days it is common to cut
with diamond blades rather than bolster or cut with fragile unsafe abrasive
cut/off discs.
Choice of saw
Bricks can be cut with any saw or grinder equipped with a diamond blade.
Even metal cut off saws and circular timber saws can be pressed into action
with dry cutting blades. The most common and efficient brick saw usually
comes equipped with 300 mm(12”) 350 mm (14”) diamond blades and the cutting
is done wet. There isn’t usually a great deal of heat so water is more for
dust control and lubrication than heat dissipation. Although some bricks
are extremely hard and require a little thought and attention to detail if
any number are to be cut.
Checking the saw
Diamond blades provide the ultimate in cost savings when they are operated
under appropriate conditions. As a rule of thumb the blade needs to
operate somewhere in the range of (7000sfpm-11000sfpm). Loosely a
350 mm (14”) blade needs to be tuned at somewhere around 2200-3000 rpm
range. Most bricksaws are set up for this speed range. Higher speeds for
softer bricks and lower for the tougher. The blade shaft needs to be an
accurate fit to the blade and there should ideally be no more than(.08mm)
0.003” between the blade and shaft diameter. The shaft bearings should have
no discernible wear to allow the blades diamonds to enjoy minimum “shock”
when cutting.
Maximum blade performance usually occurs with a new bricksaw and usually
gradually gets worse as the various moving components wear. Economically it
’s a good idea to replace the saw every few years.
Types of diamond
Just about any diamond blade design will cut the clay brick . Continuous
rim, segmented and turbo types can all be used . However for the diamond
blade to cut efficiently and self sharpen correctly it must have the right
kind of diamond / matrix composition for the type of saw, grinder, blade and
operating requirements such as wet cutting or dry cutting. Concrete brick
requirements differ from clay brick.
Cutting techniques
Assuming the selection of a correctly specified diamond blade (by a diamond
tool supplier), water should be kept to a low level where a fine spray of
water comes out of the brick being cut. More than this can cause sharpening
problems. The brick needs to be held securely in place against the table
ruler and rip gauge, and is best cut in a multiple step fashion rather than
a plunge cut. To achieve this it’s necessary to use a saw treadle to raise
and lower the blade whilst pushing and pulling the brick through it.
Tests show that this technique gives the best blade life and it definitely
helps the blades to stay sharp, safe and a pleasure to use.
Safety
Use safely equipment recommended for this kind of work. Hearing problems
(Grade 5), safety glasses, leather gloves, and if dry cutting use a dust
mask follow OSH guidelines.
Noise pollution is quite unnecessary with the advent of low cost laser
quietened diamond blades for brick saw use. Neighbours and co-workers
really appreciate the reduction in sound and O.SH. would definitely expect
all practicable steps be taken to keep sound in the “ unlikely to create
harm” category. There are many instances of saws being shut down because of
the proximity to the general public who are most unlikely to be wearing
hearing protectors as they go about their everyday lives!. High sound
levels from noisy blades damages hearing quite easily, particularly in the
upper frequencies.
Problems
The most likely problem for a clay brick diamond blade is getting blunt.
Either the diamond teeth no longer protrude sufficiently from the bond or
the diamonds become rounded, polished and blunt. To cut a lot of brick
successfully it is necessary for the diamonds to stick out from the bond
with visible bond tails, and be aggressive to the touch.
A higher content of sand in brick will increase wear of the blade
bond and could suggest a more wear resistant bond for longer life.
A clay brick blade used to cut concrete bricks will probably wear rather
quickly and it is often a good idea to buy a blade for this task. It will
have a harder matrix to resist the increased abrasion of sand in the
product.
Prices
At the time of cutting good 350 mm low noise blades for brick cutting can
be obtained for as little as NZ $250. 230 O.D. mm blades for grinders
typically $130-$150.
A small 110 mm dry cutting blade could be purchased for only $30.
Diamond blade operating instruction sheets are available free of charge
from Diamond Blade man < a.bignall@xtra.co.nz>
or fax 09 4430746.
About.com
An article on Diamond Synthesis
Largest Laser Shocks Diamond into Metal
An interesting article from Photonics Technology News
This is a neat selection of industry appropriate metric/imperial
converters.
http://chemistry.about.com/education/chemistry/library/weekly/aa112398.htm?rnk=r1&terms=diamond+synthesis
Great information on Diamonds
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