Safety Instructions for the use of Diamond Saw Blades
CAUTION: Comply with ANSI B7.1, ANSI B7.5 and OSHA regulations

Definitions
General Safety Information
Blade Safety Information
Machine Safety Information
Blade Saftey Analysis

Definitions

Warning - A safety instruction that indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

Caution - A safety instruction that indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.

Caution - General Safety Information
Responsibilities of owners and operators.

It is the responsibility:

• Before operating a saw machine the owner must provide to the operator who must fully read and understand the safety instructional materials, such as the operator's manual and SMI Rx safety booklets.
• Of the owner to provide proper training and instruction to the operator.
• Of the operator to be knowledgeable with all aspects of blade and saw machine operations.
• Of the owner to provide the operator a diamond saw blade that is in safe operating condition, as described in the Blade Safety Analysis section of this brochure.
• Of the machine owner to provide the operator a saw machine that is in safe operating condition: all guards in place and secure, all fasteners tight, all controls in proper working order and that the saw machine is in the proper configuration for the application.
• Of the operator NOT to operate a saw blade that is unsafe.
• Of the machine owner to provide the operator with information as to the correct RPM at which the blade is to be operated a proper device to measure bladeshaft RPM (tachometer), the machine components and assistance to achieve the proper bladeshaft RPM.
• Of the machine operator to make sure that the proper bladeshaft RPM is used for the size of blade. Refer to Blade Safety Information section.

Caution - When operating a diamond saw blade, wear safety glasses, safety boots, work gloves, respiratory protection (where required), hearing protection and head protection. When dry-cutting, the concrete dust can contain silicate particles which can cause silicosis, a serious lung disease, so it is extremely important to wear proper respiratory protection - contact NIOSH or OSHA for further details. When wet-cutting, avoid skin contact with concrete/asphalt slurry, which can cause serious skin irritation.

Warning - Never allow anyone to operate a diamond saw blade while under the adverse influence of drugs, alcohol, while taking medications that impair the senses or reactions, or when excessively tired or under stress.

Caution - Always operate the saw blade with someone in the area in case of an accident or injury.

Warning - It is the operator's responsibility to keep other people (workers, pedestrians, bystanders, etc.) away during sawing operations. Block off the work area in all directions with barricades, roping, safety netting, etc. for a safe distance. Failure to do so may result in others being injured by flying cuttings or debris or exposing them to harmful dust or noise.

Warning - Do not operate gasoline or diesel-powered saw machines inside of a building or other enclosed area. Exhaust contains carbon monoxide, an invisible gas which, if breathed, causes serious personal injury or possible death.

Warning - Do not operate saw blades in areas where there are combustible materials or fumes. Sparks may be caused while sawing and may cause an explosion or fire.

Caution - Do not wear loose fitting clothing. Keep hands and clothing away from all moving saw blades at all times as they may become entangled in them.

Follow all local, state and federal safety instructions or codes for operation of machinery. Follow ANSI B7.1, B7.5 and OSHA regulations.

Blade Safety Information

Make sure the diamond saw blade is of proper specification and size for the application. Diamond blades may in some cases be used with or without water. "Wet-Cutting" diamond blades MUST be used with water or other liquid as a coolant. "Dry-Cutting" diamond blades can be used with or without water. When operated dry, they are generally used on low horsepower saw machines and are operated intermittently to allow for cooling to take place. Check with the blade manufacturer as to the application/specification of the blade.

Warning - Always check the bladeshaft RPM of the saw machine before mounting the blade. Make sure the bladeshaft RPM does not exceed the maximum allowable RPM's marked on the blade you are using. Do not use a blade unless it is marked with the proper or maximum safe RPM. Failure to follow this guideline may lead to serious injury or death.

Warning - Never use a damaged blade, (i.e. excessively worn core, cracked core, segments missing, chunks out of blade, blade arbor worn or core showing signs of having been overheated). Handle all blades with care.

Warning - When using wet-cutting diamond blades it is necessary to cool with water continuously to avoid heat buildup which will cause segment loss, blade warpage and possible core failure.

Warning - Saw blades should be inspected at least twice daily for any of the symptoms described in the Blade Safety analysis section of this brochure. Blades which exhibit this wear or damage may, depending on degree or type of wear or damage, may be required to be removed from service (see Blade Safety Analysis). Contact blade manufacturer or supplier if these conditions continue to exist.

Warning - When changing blade diameter, refer to the saw machine instruction manual or contact the saw manufacturer for correct procedures. When blade diameter is changed, the blade guard, bladeshaft drive and/or engine/motor RPM MUST also be changed to maintain proper blade speed. When changing blade diameter, refer to the saw machine instruction manual or contact saw manufacturer for correct procedures.

Caution - Never twist or turn a blade in the cut as this can cause blade breakage. Use care when lowering blade into existing cut, make sure the blade is aligned with the cut. Never cut or grind with the side of the blade.

Caution - Blade Mounting
To prevent the saw from starting when mounting a blade:

• With electric start saws, make sure the ignition switch is in the off position.
• With manual or pull start saws, disconnect and isolate the spark plug wire(s) or make sure the ignition switch is in the off position.
• With air, electric or hydraulic saws, disconnect the power supply.
• Always use a bladeshaft locking-pin or a backup wrench. In other words, use proper tools as described in the operator's manual.

Caution - Inspect Blade Guard
Make sure the water tubes are clear when wet-cutting. Make sure the blade does not rub on coolant tubes and guard. Always use proper size blade guard with a splash flap.

Caution - Blade Section
Make sure you are using the proper blade specification and size for the application. If in doubt, contact the blade manufacturer or supplier.

Caution - When mounting the saw blade:

• Remove nut/bolt and outer flange.
• Inspect flanges and bladeshaft for damage.
• Make sure blade is clean and smooth under the flanges.
• Flanges should be clean and free of nicks and burrs. Inner flange should be tight on shaft.
• Shaft should be free of gouges and nicks.
• Slide blade onto shaft, do not force blade on shaft or alter the arbor hole. Make sure arrow is pointing in direction of rotation of bladeshaft.
• Flanges must be of same diameter, do not use flanges of two different diameters.
• Make sure drive pin (if provided) is properly inserted through the blade and into the opposite flange.
• The drive pin is not to be used to drive the diamond blade. The nut/bolt must be tightened sufficiently so that the driving force is through the flanges.
  (NOTE: Following flange diameter requirements are specified by ANSI B7.1)
• All steel-centered diamond blades that are less than 20" in diameter must use flanges that are at least 1/4 the diameter of the blade.
• On all saw machines other than track-mounted wall saws, all steel-centered diamond blades that are 20" and larger must use flanges that are at least 1/6 of the blade diameter.
• On track-mounted wall saws, all steel-centered diamond blades must use flanges that are at least 5" in diameter and the sawing operation must follow a step cutting procedure as follows:

• After mounting blade, remove bladeshaft locking-pin (if so equipped).

Warning - NEVER attempt to operate saw without a blade guard in place. After mounting the saw blade, install the blade guard and check to see that it is securely mounted, not damaged and blade exposure does not exceed 180º.

Machine Safety Information

Fueling or refueling of gasoline and diesel powered saws require special care. Do not smoke or use open flames when fueling. Stop the engine and always allow it to cool before refueling. Remove fuel cap slowly as fuel may be under pressure. Fuel spray/vapor is extremely flammable. Never overfill, always leave room for fuel expansion. Make sure you replace fuel cap. Clean up any spilled fuel immediately. Before starting, move fuel can/supply away from machinery. Maintain an approved fire extinguisher.

Caution - On air-powered saws always use a safety pin or wire on all hose connections. Do not turn on air supply with hoses disconnected. Always turn off air supply before disconnecting hoses.

Warning - On electric-powered saws, when making any new connections, make sure motor rotation is correct in respect to the bladeshaft threads. Follow all applicable electrical codes when making connections.

Caution - On hydraulic-powered saws, refer to the owners manual when making any new connections, make sure hose connections are tight before starting power source and make sure hoses are of sufficient strength to handle pressures in the lines.

Warning - Always be alert to the fact that there is a rotating blade on the machine. Keep hands and feet clear of blade. This is extremely important on rope/re-coil start saws.

Caution - Never start the saw with the blade in the cut, as the blade can turn as soon as machine is started or turned on. This can cause blade damage and cause the saw to kick back.

Caution - Make sure all personnel are clear of work area and out of line of the saw blade.

Caution - Never leave the saw unattended while the blade motor or saw blade is running.

Blade Safety Analysis

The operator was warned above to inspect the saw blade before mounting it, and to never use a damaged saw blade. This section lists damage to look for when inspecting the saw blade and what the common causes of that damage might be.

Segment Loss

Cause: The material and/or saw was not held firmly, which caused the blade to twist or jam in the cut, and loosen the segment.

Remedy: Always hold material and saw firmly.

Cause: Not sawing in a straight line with overcorrecting, causing the blade to twist or jam in the cut and loosen the segment.

Remedy: Properly align saw to permit square cutting, avoid twisting the blade in the cut.

Cause: Overheating due to inadequate supply of coolant (water or air). This is usually accompanied by dis-colorations which appear on the core in the area of segment loss. Overheating of blades may cause cracks or segment loss.

Remedy: Wet cutting - Provide adequate water flow to both sides of the blade. Look for spray tube blockages. Look for temporary loss of water due to equipment running over water feed hoses. Always support the water feed hoses that cross traffic lanes.

Dry Cutting - Periodically allow blades to run out of the cut. The blade will cool in a few seconds so that sawing may continue.

Cause: Core worn thin as a result of undercutting by abrasive fines generated during cutting. (Core wears to a knife edge, which weakens the core and causes a segment to be separated.)

Remedy: If generated fines are highly abrasive, wear-resistant cores should be used to retard undercutting. When wet cutting, use sufficient water to flush fines out of cut.

Cause: Defective flanges which cause the blade to flutter in the cut or fail to adequately support the blade in perfect alignment.

Remedy: Clean foreign material from flange surfaces, or replace flanges if they are under manufacturer's recommended diameter or are bent or deformed.

Cause: Blade is too hard for material being cut causing excessive dullness and the segment separates due to impact or fatigue. (This can also be the cause of frictional heat, which can possible melt the brazing solder, which can cause separation of the segment from the core.)

Remedy: Use the proper blade with a specification for the type of material being cut.

Cause: Blade is cutting out of round resulting in a pounding impact.

Remedy: Replace worn parts (bearings, machine bladeshaft, etc.). Refer to the saw machine manufacturers Parts and Service Manual for proper procedures.

Cause: Improper blade operating speed which produces high pressure on the segments and subsequent failure of the brazed joint, core, or segment.

Remedy: Make sure bladeshaft RPM of the equipment is specified when ordering blades. The bladeshaft speed should be checked with a tachometer to ensure that each diameter blade does not exceed the blade manufacturer's recommended RPM.

Cracks in Segment

Cause: Blade is too hard for material being cut.

Remedy: Use blade with softer bond.

Core Warpage
If blade has been warped (dark blue color) it is damaged beyond repair. Discontinue use.

Cause: Blade core has been overheated.

Remedy: Wet Cutting - provide proper amount of water to both sides of blade. Check to make sure water supply is producing sufficient water and that no blockages occur in water lines.

Dry Cutting - Periodically allow blades to run out of the cut. The blade will cool in a few seconds so that sawing may continue.

Cause: Blade core has been overheated as result of blade spinning on spindle.

Remedy: Check spindle and arbor hole for damage. Tighten spindle nut to machine manufacturer's specified torque or tightness and make certain that the drive pin (where used) is in place.

Cause: Blade core has been overheated because of blade core rubbing side of material being cut.

Remedy: Properly align machine to permit square cutting. Avoid twisting the blade in cut. Maintain a firm grip on material and/or saw. Make certain that spindle RPM is correct so that blade operates at its recommended speed.

Cause: Unequal pressure on flanges.

Remedy: Flanges should be identical in diameter and of the recommended size.

Cause: Machine bladeshaft RPM does not match blade RPM.

Remedy: Use blade with proper RPM to match machine bladeshaft RPM.

Blade Wobbles

Cause: Blade mounted on a damaged or worn machine.

Remedy: Check for damaged or worn bearings, bent or worn blade spindle. Also check flanges to make sure they are clean, flat, and of the diameter recommended by the manufacturer.

Cause: Blade being run at improper operating speed (RPM).

Remedy: Make certain that the bladeshaft is turning at the proper RPM to match the manufacturer's recommended speed of the blade. Use a tachometer to make certain bladeshaft is set at proper operating speed.

Cause: Blade core is out of tension. Saw blades are tensioned by the manufacturer to rotate true when run at their design speed. Loss of tension can be caused by operating at excessive speed, damage due to impact or dropping or from overheating of the core.

Remedy: Do not use a blade that is out of tension, contact saw blade manufacturer or supplier.

Cause: Surface of blade core is not clean and smooth underneath the flanges.

Remedy: Make certain blade core is not dirty, worn or damaged underneath the flanges.

Cause: Blade bent.

Remedy: Do not use a bent saw blade, contact manufacturer or supplier.

Core Cracks

Cause: Blade wobbling due to operating at too high an RPM, due to blade loss of tension or blade core worn.

Remedy: Do NOT continue to use the blade. Replace with new blade.

Blade core Undercutting

Cause: Abrading or wearing away of the steel center faster than the diamond segment. (Highly abrasive fines are being generated during cutting.)

Remedy: If generated fines are highly abrasive, wear-retardant cores should be used.

Wet Cutting - use sufficient water to flush fines out of cut.

CAUTION: Wear-retardant cores are not always the final answer to eliminating undercutting. Blades should be inspected periodically during use.

Out of Round Blade Wear

Cause: Worn bladeshaft bearings on saw machine.

Remedy: Install new bladeshaft bearings or bladeshaft as required. Refer to manufacturer's service manual.

Cause: Engine not properly tuned on saw machine, causing "hunting" or engine surging.

Remedy: Tune engine.

Cause: Blade arbor hole damaged from previous mis-mounting.

Remedy: Discontinue use of blade.

Cause: Blade spindle worn. A groove may have been scored on the spindle as a result of pervious blade spinning on the spindle.

Remedy: Replace worn bladeshaft.

Cause: Blade slipping on spindle.

Remedy: Properly tighten spindle nut on machine. Make certain drive pin is functioning where supplied.

Cause: Bond too hard for material causing machine to "pound".

Remedy: Use proper blade specification for the application.

Arbor Hole Out-of-Round

Cause: Flanges are not properly tightened, permitting blade to either rotate or vibrate on spindle.

Remedy: Wrench-tighten spindle nut to make certain blade is adequately secured to prevent rotation on spindle.

Cause: Worn, bent, or dirty flanges which do not allow proper blade clamping.

Remedy: Clean or replace flanges, make sure that they are not worn, and tighten spindle nut properly.

Cause: Blade not properly mounted.

Remedy: Make certain blade is mounted on the proper diameter of spindle before tightening spindle nut. On concrete saws, make certain that pin hole slides over drive pin. Never depend on drive pin to actually drive blade. A drive pin is simply a safety measure to prevent the blade from spinning on the spindle, should the nut become loose.

Blade will not cut - Blade is Dull
A diamond saw blade is defined as dull when the diamond particles have lost their sharp edges, too many diamonds have been lost from the surface of the segment or the diamonds have been covered up by metal matrix material being smeared over the diamonds. When any or all of these occur, the blade will no longer cut properly and can be easily overloaded, causing other problems, such as those described in the above sections, to occur.

Cause: Blade is too hard for material being cut. (Improper blade specification.)

Remedy: Consult blade manufacturer or supplier for the proper blade specification for the material being cut.

Cause: Blade has become dull, probably as a result of being used on too hard a material.

Remedy: Dress or sharpen by cutting softer abrasive material to expose diamonds. if continual dressing is required, this would indicate that the blade specification is too hard for the material being cut.

Cause: Failure to initially break in new blade on specific material being cut.

Remedy: Allow blade to sharpen itself on the material to be cut when first placing it on the saw. This is the proper way to break in a blade. Do not force the blade into the cut as this will generally aggravate the problem.

Cause: Insufficient power to permit blade to cut properly.

Remedy: Use adequate horsepower for cutting application and/or use correct voltage at motor. Tighten belts in accordance with machine maintenance instructions.

Cause: Dry Cutting - Blades will become dull as a result of overheating and diamond rim or segments will "mushroom" or melt and deform.

Remedy: Dry Cutting - Discontinue use, contact blade manufacturer or supplier.

Complete Rx for Diamond Blades and Concrete Saws are available through AEM or DITEQ.

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