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Bespoke Tool Service

Diamond core drill uk


Choosing a diamond blade

For the best performance and life, choose a blade which has been designed for the type of material to be cut. The chart below gives an indication of the optimum cutting range for each Encore blade. Larger blades can be re-tipped with the correct segments. If in doubt, contact us.

Choosing a diamond core
Dry diamond cores are suitable for drilling holes in brick and block walls, with minimum mess. For drilling granite or reinforced concrete, wet diamond cores are available in a range of sizes, or can be made to customers' specifications: bespoke tools. Cores can be re-tipped if barrels are in good condition, contact us.

Diamond tools for stone
Cutting, shaping and polishing stone can be a simple task or a large undertaking. We stock a wide range for both natural and synthetic stone and can also design to order, as we did for the Princess Diana Memorial Fountain. We are happy to advise you: contact us.

Blade Safety

  1. DO clean the flanges before mounting the blade and check both plates are same diameter.
  2. DO ensure that the blade is correct for the material being cut.
  3. DO ensure that the arrow on the blade corresponds with the direction of rotation of the machine spindle.
  4. DO ensure that the blade is in balance and running true. A blade which is out of balance means increased wear and possible destruction of the saw. Ensure that the blade is concentric to within 0.15mm
  5. DO ensure that the machine bearings and spindle are not worn, or blade life will be reduced.
  6. DO avoid tilting the blade when cutting.
  7. DO only use machines which have an approved safety guard.
  8. DO remove the blade from the machine during transit to prevent accidental damage.
  9. DO inspect blade frequently to detect cracks or undercutting to steel centre.
  10. DO observe the Abrasive Wheels Regulations 1970.
  11. DO ensure that the machine is not dropped on the blade.
  12. DO always wear appropriate protective equipment including head, ear and eye protection plus gloves and safety footwear.
  13. DON'T use your blade on metals or other unsuitable materials. If you have any doubt call our office.
  14. DON'T apply pressure and force your diamond blade through the cut. The weight of the machine will suffice. increased pressure means increased wear.
  15. DON'T let excessive heat be generated at the cutting edge of the blade.

Wet Cutting

  1. DO ensure adequate water supply to both sides of the blade.
  2. DO ensure that the blade cuts parallel to the wheel axis.
  3. DO follow the manufacturer's recommended pulley sizes and operating speeds for specific blade diameters.
  4. DO tighten drive belts to ensure full available power.
  5. DO use drive pin fitted to the machine.
  6. DON'T force blade on blade shaft or mount blade on undersized spindle.
  7. DON'T use paper washers to pack out the clamp plates.
  8. DON'T force the machine so that the blade rides up out of the cut.
  9. DON'T operate machine with damaged or open blade guard.

Water Flow Required for Wet Blades
Blade Dia mm Litres per minute
250 6
300 - 550 15
600 - 900 30
1000 -1200 50

Safe Operating Speeds
Dia mm Operating rpm Maximum rpm
230 4000 6800
300 3000 5100
350 2600 4400
400 2300 3850
450 2000 3400
500 1800 3050
600 1500 2550
650 1400 2350
700 1300 2190
750 1200 2050
800 1135 1910
900 1000 1700
1000 900 1530
1200 750 1275

Core Safety


The dry diamond core drill is designed to give rapid, clean service entries in brick and internal wall materials with virtually no making good. It is ideally suited for plumbers, heating and ventiliating engineers, electricians, kitchen fitters and general builders.

Using the standard 1000W, variable speed electric drill with clutch, the coring action is totally rotary enabling the operating noise and vibration to be reduced to the minimum. We recommend using the pilot hole method but if a tungsten pilot drill is used it must be knocked out after the core drill enters.

Adaptor pack consists of a drive adaptor, pilot spigot and ejector drift, required for sizes 32mm to 152mm. The 22mm and 28mm fit directly into a standard drill chuck without adaptor. Extension rods are available upon request for increasing depthwithout loss of performance.


  1. Pilot drill the wall first with 13mm masonry drill.
  2. Follow through with the diamond core drill.
  3. Use 900 watt rotary drill minimum, fitted with clutch for safety and variable speed if possible.
  4. DON'T use hammer action when drilling with diamond core drills.
  5. Use machine at between 900-1300 rpm. The harder the brick the larger the diameter of the core drill, the slower the rpm. Faster rotational speed does not necessarily mean better penetration.
  6. Make sure the chuck is tight.
  7. Make sure the material is cleared at regular intervals. A build up will cause over-heating and extensive clutch wear, together with a possible loss of segments.
  8. Rotate core drill when entering and exiting hole.
  9. Try to ensure constant level of machine.
  10. DON'T force the core drill, let it do the work. This will prolong life and reduce breakage.
  11. If core drill starts to vibrate reduce pressure.
  12. If core drill slows down dramatically we suggest drilling very abrasive material to open up the segment.
  13. Treat your core drill with. DON'T put a wrench on it. Replace in box after use. Remember, it is a DIAMOND product.

Problem Diagnosis

Rapid Wear

Blade spcification is too soft for the materials being cut causing the diamond to become over-exposed. Use a blade with a harder bond system. Loose drive belts causing intermittent revolutions. Inadequate water supply caused by blocked or damaged water inlets.


The effect of premature wear of a steel blank is a particular problem in highly abrasive materials such as asphalt and green concrete. The steel blank wears to a knife-edge just below the segment and may result in segment loss.

Ensure the blade has undercut protection on steel centre to assist in the removal of slurry from the cut and protect the steel centre. Ensure that the blade is not cutting bleow the asphalt into the sub-base below, as this constant rubbing in the loose material results in premature wear and can be dangerous. Check water supply, as increased water flow will help wash slurry from the cutting area and reduce undercutting.

Segment Loss

The material was not held firmly, causing the blade to twist or jam in the cut. Twisting or turning the machine while the blade is in the cut. Blade too hard for the material being cut, resulting in the blade hammering in the cut. Blade flanges are worn or deformed and fail to provide proper support, causing the blade to deflect in the cut. Foreign material between the flange and the blade blank causing the blade to flutter, resulting in segment loss due to impact or fatique.

Segment Cracks

Blade specification is too hard for materials being cut, causing hammering in the cut. Use a blade with a softer bond system. Peripheral speed of blade too hight. Check rotational speed of blade.

Blank Cracks

Blade is too hard for the material being cut. Excessive cutting pressure, resulting the blade blank bending and flexing. Insecure mouting, causing fluttering of the blade. Ensure blade is correctly mounted, drive pin used and clamp nut tightened.

Blade Will Not Cut

The bond is too hard for the materials being cut; check the specification is correct. Glazed blades can be opened up by cutting a soft, brasive material. Machine has insufficient horsepower for the specification being used or the machine drive belts need retensioning. Ensure correct direction or rotation.


A common cause of blade failure. Overheating can cause many other possible problems, such as loss of tension, blank cracks and segment loss. Overheating can be shown by black or blueish discolouration on the steel blank.

For wet blades - inadequate water supply can be caused by blocked or damaged feed inlets. Trcikle feed for dust suppression can cause excessive abrasion. Do not push blade too hard, allow the blade to cut freely.

Uneven Segment Wear

Wet cutting - insufficient water, generally on one side of the blade. Flush water system and ensure water is equally distributed to both sides of the blade. Blade is worn out of round due to bad bearings or worn shaft. Replace and repair bearings or shaft as required. Segments worn on one side reducing side clearance (check alignment). Check wheels and wheel alignment on floor saw and carriage alignment on masonry bench saws.

Loss Of Tension

Blade blank has been overheating. Ensure sufficient water supply for wet cut blades. The bond is too hard for the application causing the blade to deviate in the cut. Check machine is running at the correct R.P.M., that there is no wear on machine bearing sharft and that the flanges are of the correct and same size. Ensure blade is secure and not spinning on the spindle. Check that the drive pin is in place on all floor saws. Ensure that the blade cuts in straight lines only.

Out of Round

Blade shaft bearing may be worn. Fit new bearing and ensure regular lubrication. The blade is too hard for the material being cut, resulting in the blade hammering and glazing. Choose a blade with a softer bond. The machine spindle may have a groove scored in it as a result of a previous blade slipping on the spindle.

Damaged or Distorted Arbor Hole

Blades incorrectly aligned when mounting, causing the blade to hammer. Ensure blade is mounted on the proper diameter of the spindle before tightening. Ensure that pin hole slides over drive pin. Flanges are not properly tightened or cleaned allowing the blade to spin or vibrate on spindle. Saw shaft is badly worn or grooved, allowing the blade to pound.

Frequently Asked Questions (FAQs)

Diamond Blades

Diamond Cores

Grinding Wheels

Tools for Stone

Diamond Blades

Q Which blade should I choose?
A Start with the material to be cut, then choose the correct size and fitting for your machine. Each blade is designed for specific materials, and choosing the correct blade for the application will give you the best life and performance from your blade.

Q What if my bore size is non-standard?
A We stock a certain amount of non-standard bores in the most popular blades, and are happy to adjust bore size to suit customer requirements. Depending on the size of blade, sometimes a small charge may be made to cover the cost of re-sizing.

Q Do Encore make larger blades?
A Blades over 850mm are normally made to order as these are designed for specific machine requirements. We are happy to quote for any size blade.

Q Is it possible to re-tip a blade?
A Yes, providing the blank is not distorted or damaged. We will be happy to give you a quote for re-tipping.

Q What if I have a problem during cutting?
A Please get in touch with us immediately when we will recommend the best course of action to take. Our problem diagnosis section may also help.

Q Why should I choose to buy Encore blades?
A Encore design blades to a high specification which are manufactured to exacting quality standards, guaranteed against defect. Should you encounter problems with any of our products contact us immediately.

Diamond Cores

Q What type of core do I need?
A For masonry, brick and block walls, dry cores can be used for minimum mess. For granite and reinforced concrete, it is necessary to use a wet core.

Q Do I need to use a special drill?
A Dry diamond cores must only be used with a rotary action drill, fitted with a clutch for safety. See our safety guidelines for details. Wet cores are used with a pillar drill or CNC machine, depending on the application.

Q Do Encore make non-standard sizes / lengths?
A We are happy to quote for any diameter / length of core; just tell us what you require.

Q Is it possible to re-tip a core?
A Yes, providing the barrel is not distorted or damaged. We will be happy to give you a quote for re-tipping.

Q What if I have a problem during cutting?
A Please get in touch with us immediately when we will recommend the best course of action to take. Our problem diagnosis section may also help.

Q Why should I choose to buy Encore cores?
A Encore design cores to a high specification which are manufactured to exacting quality standards, guaranteed against defect. Should you encounter problems with any of our products contact us immediately.

Grinding Wheels

Q Which fittings are available?
A M14, 22.23, Snail Back, Hilti, Makita

Q What about grinding floors?
A Encore make floor grinding plates up to order, for any type of machine.

Tools for Stone

Q I need to use a blade flush mounted - do you have them?
A Encore can fit a flush cut adaptor to any blade - please ask.

Q Can I polish concrete to make a work top?
A Yes, it polishes up well, but unlike granite you do not need a full sequence of pads.

Q I have a particularly tricky job to do in stone - and can't find a tool to do it.
A Don't worry! Encore have years of experience in solving this type of problem. We can design and make a special tool very quickly if necessary. Contact us to discuss your application.

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