Blade Descriptions - Blade Depot

The following is a list of blade types with their description.  Photos of all blades are found in the Blade Depot Section of Norstone’s website.

Note that almost all blades can be coated with alumina, tungsten carbide, polyurethane and glass.  Some can be made entirely from PTFE, polyethylene, polypropylene, polyamide or polyurethane.

TYPE 1: ANGLED TOOTH BLADE/COWLES AS WELL AS TYPE 6: SQUARE TOOTH BLADE/F STYLE:

Popular blade for dispersion work. Primarily a high shear blade. There are many designs that are efficient and have proven to be an excellent blade for shearing. There are newer technologies that provide more pumping with shear. Stock sizes from 1″ and larger. We recommend sizes of 1.5″ and larger. The variations on the tooth do not appear to make a significant difference but the number of teeth can.

• Keeps air entrainment to a minimum
• Gets very sharp with use
• Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
• Requires Stiffening Plates
• Can be hard coated for longer life
• Only goes in 1 direction
• 5000-5500 fpm tip speed

TYPE 1S: SERRATED TEETH ANGLED TOOTH BLADE

This is similar to a Type 1 or 6 with serrated edges at the top of the teeth. Many customers like this blade but Norstone testing indicates that if the material is not low viscosity, it can entrain air and/or create foam.

• Gets very sharp with use
• Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
• Requires Stiffening Plates
• Can be hard coated for longer life
• Only goes in 1 direction
• 5000-5500 fpm tip speed

TYPE 2/TYPE 2G: HIGH VANE BLADE/G STYLE

High pumping low shear action. This blade is for mixing on a high speed disperser with minimal shear and heat build-up. This blade is popular in the mixing and let down of coatings but also to assist high speed shear blades processing high viscosity materials.  It is available in sizes from 2″ and up.

• Gets very sharp with use
• Draws more amps than Type 1 or Type 6
• Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
• Requires Stiffening Plates
• Can be hard coated for longer life
• Only goes in 1 direction
• 4500-5500 fpm tip speed

TYPE 3: COMBINATION BLADE/E STYLE

This blade offers a combination of high shear along with excellent batch movement and cutting in fibrous or higher viscosity materials. It is excellent for high solids as well. Popular when dispersing nitrocellulose. Available in sizes from 2″ and up.

• Shears, Pumps and Cuts
• Gets very sharp with use
• Excellent for chips, fibers, cellulose, resins, high viscosity & high solids
• Draws more ampts than Type 1 or Type 6
• Requires Stiffening Plates
• Can be hard coated for longer life
• Only goes in 1 direction
• 5000-5500 fpm tip speed

TYPE 4: AGGRESSIVE SHEAR BLADE

This blade works well on materials difficult to de-agglomerate but draws higher amps and surges. It is available in sizes from 2″ and up.

• High Shear Blade with larger teeth for more aggressive action;
• Better at pumping than standard high shear blades;
• Not very popular due to its strong surging and power draw
• Gets very sharp with use.
• Requires Stiffening Plates
• Only goes in 1 direction
• 5000-5200 fpm tip speed

TYPE 5: PICK BLADE

This blade is perfect for cutting in or shredding rubber, waxes and other soft materials that tend to gum up on standard impellers. Unique design features a knife (or pick) extending out from the blade, alternating with vertical teeth. This blade is available in sizes from 2″ and up.

• Gets very sharp with use
• Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
• Requires Stiffening Plates
• Only goes in 1 direction
• 5000-5500 fpm tip speed

TYPE 6: SQUARE TOOTH BLADE/F STYLE AS WELL AS TYPE 1: ANGLED TOOTH BLADE/COWLES:

Popular blade for dispersion work. Primarily a high shear blade. There are many designs that are efficient and have proven to be an excellent blade for shearing. There are newer technologies that provide more pumping with shear. Stock sizes from 1″ and larger. We recommend sizes of 1.5″ and larger. The variations on the tooth do not appear to make a significant difference but the number of teeth can.

• Keeps air entrainment to a minimum
• Gets very sharp with use
• Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
• Requires Stiffening Plates
• Can be hard coated for longer life
• Only goes in 1 direction
• 5000-5500 fpm tip speed

TYPE 7M: METAL VERSION OF THE TYPE 7 DHS POLYBLADE WITH DIAMOND TEETH AND SCOOPS

• Diamond shaped teeth in between scoops
• 6/2:  6 scoops with 2 teeth in between
• 6/3: 6 scoops with 3 teeth in between
• 9/1  9 scoops with 1 tooth in between
• Aggressive shearing with pumping to help move the fluid more efficiently
• Similar shear to Type 1 & Type 6 with the addition of pumping
• Bi-directional
• Available in Aluminum, Stainless steel, Carbon Steel
• Only use if metal is preferred over polymers
• Does NOT need stiffening plates
• Excellent for hard agglomerates and chunks like press cake
• Excellent for high temperature applications above 450F
• Can also be made available in ceramic

TYPE 7STD: ORIGINAL DESIGN, SCOOPS ONLY

• High shear with excellent pumping
• Never gets sharp eliminating a safety hazard from the plant.
• May run louder than steel blades
• Far outlast steel blades – polymers are more resistant to wear than steel
• No teeth to bend
• Bi-directional. Can be flipped over for a new blade when the initial side is worn.
• Requires plates to prevent the holes from stretching
• Available in many materials of construction but primarily in high abrasion resistant urethane and anti-static ultra high molecular polyethylene
• Runs cooler than steel blades and competitive polymer blades due to its end-to-end radius scoop
• External stiffening plates are required;
• The blade is thick but can be counterbored and drilled to fill all shaft configurations;
• All Polyblades can have hubs attached to them for mounting mid-way on shaft
• 4000-4500 fpm tip speed

URETHANE TYPE 7STD: BLADE CONFIGURATIONS: TYPE 7DH – TYPE 7STR – TYPE7STR/RP – TYPE7EP

• These designations apply to urethane blades only
• DH: Dual Hard blades that are made with an inner diameter of hard urethane for support and an outer perimeter of abrasion resistant urethane

Expensive and time consuming to make but still the most popular style. External Stiffening plates required.

• STR: Soft Tear Resistant that are made with an abrasion resistant urethane throughout. This formulation is only good for blades <12” diameter.
• STR-RP: Soft Tear Resistant made with ¼” thick internal plate. Longer life than the dual hard.

External stiffening plates required.

• EP: Soft Tear Resistant made with ½” – 5/8” thick internal plate either round or clover shaped depending on blade size. External stiffening plates are NOT required if blade has the following internal plate:
  ¼” thick plate   6” – 16” diameter blade
  3/8” thick plate  12” – 18” diameter blade
  ½” thick plate 16” – 20” diameter blade
  5/8” thick plate 20” – 32” diameter blade

TYPE 7EP: POLYBLADE WITH EMBEDDED PLATE

• Cast Polyurethane Blades can have a REINFORCED plate embedded into the blade for improved stiffness eliminating the requirement for external plates;
• The internal plates can be precision machined or dynamically balanced for safe machine operation at high speeds;
• This design eliminates all metal exposure;
• The internal plate is a one piece assembly which is especially helpful in confined space entry situations;
• Round Plates for smaller sizes and Clover Plate for larger sizes due to increased torque.

TYPE 7SP: POLYBLADE WITH TURBO PEGS

• (3) Square Turbo Pegs on the perimeter in between scoops added to both sides to increase the cutting ability of the blade;
• Option for the stiffening plate molded into the blade eliminating the need for stiffening plates (see Type 7EP)
• Bi-Directional
• Pegs improve dispersion in higher viscosities
• Pegs may cause splashing in low viscosities
• 4000-4500 fpm tip speed

TYPE 7HS: POLYBLADE WITH HIGH SHEAR TEETH & SCOOPS

The most aggressive Polyblade style available with scoops and teeth.  Never gets sharp, reversible, and long lasting.  Used for maximum dispersion with pumping. Several configurations available.  The newest style and growing quickly in popularity due to its ability to disperse quickly in all viscosities. Stiffening plates must be used. Embedded plates are available with the urethane blades.

• Newest design for maximum cutting and pumping power
• Options for 0, 3, 6 or 9 scoops to determine level of pumping
• Options for 2 or 3 teeth in between the scoops to determine grinding efficiency
• Options for Diamond, Wedge or Bowtie teeth on all blades except urethane (Diamond only)
• Options for 7HS-LF, high shear laminar flow with no scoops but additional option for teeth on the perimeter
• Doesn’t sharpen with use
• Bi-directional
• Excellent for a wide range of viscosities
• Available in a wide range of materials
• Requires stiffening plates
• 3500-5000 fpm tip speed depending on desired results
• Free 30 day trial

Available Configurations for the Type 7 HS Blade

TYPE 7DHS: DIAMOND SHAPED TEETH

• Diamond shaped teeth in between scoops
• 6/3:  6 scoops with 3 teeth in between, 4800-5300 fpm
• 9/2  9 scoops with 2 teeth in between, 4500-5000 fpm
• More aggressive than standard Polyblade
• Similar shear to Type 1 & Type 6 with more pumping
• Available in UHMW and cast urethane

Type 7EPDHS/TP: DHS DESIGN IN ABRASION RESISTANT URETHANE

• Diamond shaped teeth & Turbo Pegs in between scoops
• (3) set of 2 scoops set evenly around blade
• (3) diamond shaped teeth between each set of scoops
• (1) turbo peg in between each pair of scoops
• Internal Clover shaped stiffening plate
• External plate design also available
• Turbo Pegs can be eliminated as an option
• Not available in all sizes
• More aggressive than standard Polyblade
• More abrasion resistant than AntiStatic UHMW
• Similar shear and pumping to Type 11 but dual sided and lasts longer

TYPE 7WHS: WEDGE SHAPED TEETH

• Wedge shaped teeth in between scoops
• 6/3:  6 scoops with 3 teeth in between, 4800-5300 fpm
• 9/2  9 scoops with 2 teeth in between, 4500-5000 fpm
• Most aggressive of the Polyblades
• Maximum shear with pumping for hard to grind products and high viscosities
• Generates heat fast

TYPE 7BHS:  BOWTIE SHAPED TEETH

• Specialty blade for large agglomerates that don’t break down with shear
• Bowtie shaped teeth in between scoops
• 6/3:  6 scoops with 3 teeth in between, 4800-5300 fpm
• 9/2  9 scoops with 2 teeth in between, 4500-5000 fpm
• Maximum disruption of a batch sometimes needed in an emulsion
• Good for breaking chunks

TYPE 7LF: DIAMOND SHAPED TEETH WITH NO SCOOPS, OPTION FOR TEETH ON THE PERIMETER

• Diamond shaped teeth on top, bottom and/or perimeter
• No scoops
• 6/3:  6 spaces with 3 teeth in between, 5500-6000 fpm
• 9/2  9 spaces with 2 teeth in between, 5500-6000 fpm, less aggressive
• Use when high shear or homogenization is required and pumping is not needed or detrimental

TYPE 7OS: SINGLE SIDED POLYBLADE, ANY STYLE

• Purpose is to reduce the amount of air entrained in the batch
• Flat side up; Scoops & Teeth face down
• Reduced vortex above the blade
• Available in any size
• Available in most materials

TYPE 8: MIXED FLOW

The Mixed Flow is a very popular impeller for high speed mixing up to 200 gallons assuring that material is mixed in all directions. Available in regular and high vein with collar and set screw. This blade is more effective than a standard 3 bladed prop. The blade should be sized to be 1/3-1/2 the diameter of the tank. Sizes range from 1-7/8” – 8” diameter.

TYPE 9: LOUVER MIX BLADE

The Louver Mix Blade is excellent for lifting quick settling materials off the bottom of a tank in medium to high viscosity materials or blending pigments. The louvers formed in the plane of the blade provide maximum pumping action giving positive over all material movement with excellent top to bottom flow. This blade is capable of both shear and agitation. It can be used on a mixer shaft or high speed disperser. Positive material movement; good blending and shear for the more fibrous additives and fillers. Sizes range from 2” and larger.

TYPE 10: MULTI FIN PUMPING MIX BLADE

The Multi Fin Pumping Mix Blade has louvers formed in the plane of the blade provide maximum pumping action giving positive over all material movement with excellent top to bottom flow. It causes a lot of surging and air entrainment. Sizes range from 2” and larger.
Available in PTFE.

TYPE 11: DISPERSING MPELLER WITH TOP PUMPING LOUVRES

Type 11: The louvers formed in the plane of the blade provide maximum pumping action giving positive over all material movement with excellent top to bottom flow. They are excellent for lifting quick settling materials off the bottom of a tank in medium to high viscosity materials. The ITT is for high shear and agitation. High positive material movement. Recommended where high shear is required for a rapid and smooth blend or when high shear is not required but is not detrimental. This Impeller should be 1/2 – 1 full diameter of the bottom of the tank with at least twice as much above the blade or it will suck in air.

Rules for the Type 11 blade are as follows:

• 1/2 – 1 full blade diameter off bottom with 1.5 – 2 blade diameters of fluid above the blade;
• 4000-4500 fpm tip speed;
• Impeller size should be 1/3 diameter of tank for standard materials; high viscosity can take up to 50% the diameter of tank.

TYPE 11S: DISPERSING IMPELLER WITH TOP & BOTTOM PUMPING LOUVRES

Type 11S: The louvers formed in the plane of the blade provide maximum pumping action giving positive over all material movement with excellent all around flow as the louvres are flat planes piercing both above and below the blade. Excellent for lifting quick settling materials off the bottom of a tank in medium to high viscosity materials. This Impeller should be 1/2 – 1 full diameter of the bottom of the tank with at least twice as much above the blade or it will suck in air.

• Impeller size should be 1/3 diameter of tank for standard materials; high viscosity can take up to 50% the diameter of tank.
• Available with serrated teeth
• Has rectangular pumping louvres which alternate 1-up and 1-down
• A lot of edges that can get very sharp
• Great for cutting
• Works for a wide range of viscosities
• Might cause foaming
• Stiffening plates are required
• Can be difficult to clean;
• Will aerate some products;
• Excellent for chopping and cutting;
• 4000-4500 fpm tip speed

TYPE 12: PROPELLER

The Propeller blade is a boat prop commonly used as a mixing blade.  Just like a boat, it mixes the material in one direction.  It is a classic design used in many applications. However, there are many blade styles currently available which are superior to this technology. They have limited reach and get very heavy as they increase in size. They are available in both right hand and left hand, stainless or aluminum. Sizes start at 1” and larger.

TYPE 13: AXIAL FLOW TURBINE

The Axial Flow Turbine is the most common slow speed mixing blade. The arms of the blade are usually set at a 45-degree angle. Several blades can be stacked on one shaft so that this blade works well in a tall tank. The blade pushes product down or lifts up depending on the angle of the impeller creating a rolling action.  A Split Hub Design is available for easy removable or installing in a tank with limited access opening. The impeller can have bolted or welded blades/fins. The smallest size is limited by the shaft diameter as it attaches with a collar and set screw.
Available in PTFE and Urethane.

TYPE 14: HIGH EFFICIENCY AXIAL FLOW TURBINE

The High Efficiency Axial Flow Turbine is not new but a more recent version of Type 13 that both reduces the amp draw and is able to spin at higher speeds. It works well at slow and high mixing speeds in viscosities less than 1000 cps. A Split Hub Design is available, as well as various materials of construction.  The smallest size is limited by the shaft diameter as it attaches with a collar and set screw.
Available in PTFE, Nylon and Polypropylene.

TYPE 15: STRAIGHT RADIAL TURBINE

This Straight Radial Turbine blade moves product to the outside only. The fins of the blade are set at 90 degrees. This style is commonly used at the bottom of the shaft of a square shaped tank. It draws a lot of power and does not move product efficiently vertically. A Split Hub Design is available, as well as various materials of construction.  The smallest size is limited by the shaft diameter as it attaches with a collar and set screw.

TYPE 16: CURVED RADIAL TURBINE

The Curved Radial Turbine blade moves the product into the center and then pushes it out to the sides with an aggressive whipping action. It has a high amp draw and provides good mixing of particles. The blade can be expensive compared to other types but is excellent for sweeping corners of a square tank. A Split Hub Design is available, as well as various materials of construction.  The smallest size is limited by the shaft diameter as it attaches with a collar and set screw.

TYPE 17: COLLAPSIBLE

The Collapsible Blade is designed to fit through the small bung hole in a closed head drum so it is also called a Bung Hole Blade. Larger versions are available to fit through a tote opening. As the shaft spins the fins open up into the shape of an axial flow blade. It is critical that the shaft speed and horsepower torque are adequate to move the blade fast enough to cause it to open. The smallest size is limited by the shaft diameter as it attaches with a collar and set screw.

TYPE 18: BUTTERFLY BLADE

The Butterfly Blade is used for mixing very high viscosity materials. A scraper blade can be attached to the blade for scraping the side or bottom of a tank. Smallest blade is 3”.

TYPE 19: BOWTIE BLADE

The Bowtie Blade is more common than the Butterfly Blade but also used for mixing high viscosity materials. It has a flat bottom edge.  Scraper blades can be attached to this blade for scraping both the bottom and sides of a tank. Smallest blade is 2”.

TYPE 20: TRN BLADE, SLOW SPEED MIXING, REDUCES AIR ENTRAINMENT

The TRN blade is a very slow speed mixing impeller that moves fluid in a radial direction. Although it looks simple, this blade has an unexpectedly powerful ability to mix low to medium viscosity materials and not entrain air. This blade must run at low tip speeds. Two blades may be required to ensure that product at the bottom is incorporated into the batch. Blades can be purchased welded to a shaft or stand alone with collar and set screw.  Smallest blade is 4”.

TYPE 21: PLUNGER

The Plunger blade is used for mixing and scraping material off the bottom of the vessel. Material of construction is Zinc-Aluminum Alloy complete with shaft. Sizes available are 1”, 2″, 3′, 6″, 8″ and 12″. This blade is a very economical option. Largest size is made to fit 55 gallon drum quantities.

TYPE 22: PADDLE

The Paddle blade is designed for slow speed mixing.  It is a low cost blade with a very gentle action.  Most paddle blades mix in the radial direction only.

TYPE 23: RUSHTON

The Rushton impeller is designed for use with gas/gas and gas/liquid.  It provides a simple radial flow pattern that moves material from the center of the vessel outward where it flows along the outer walls of the tank. It is most commonly used in reactor tanks, two phase mixing (liquid/gas). It is not efficient for mixing liquid/liquid, liquid/powder, powder/powder. It draws a high amp per volume. Sizing is 1/3 tank diameter.

TYPE 24: JIFFY MIXING BLADE

The Jiffy blade is designed for mixing products with a paint consistency. Made from stainless steel, it can easily attach to a hand-held electric drill. It is widely used by contractors in the field.  The smallest blade is for 1-2 gallons and sizes go up to 10 gallons.

TYPE 25: D BLADE/MULTI LAYER RING STYLE

Also known as a Ring Blade, this impeller consists of three plates welded together with “cutting teeth” in between. Provides excellent shear using the Venturi principal. Requires a 5800 fpm +/- 5% tip speed. Trial sizes available.
Rules for the D blade:

• 1/2 – 1 full blade diameter off bottom with minimum of 2 blade diameters of fluid above the blade.
• Most expensive blade but provides energy close to that of a rotor stator
• Can be challenging to clean
• Can clog with large agglomerates
• Works in one direction only
• Blade size should be ¼-1/3 diameter of tank for standard materials; higher viscosities can use up to 40% the diameter of tank.
• Viscosity Range: 1,000 CPS to 10,000 CPS. It has been used up to 50,000 CPS and lower than 1,000 CPS depending upon specific gravity
• Does not require stiffening plates
• 5800 fpm-6000 +/- 5% tip speed
• Confirm the disperser can travel at tip speeds this high

TYPE 26: HELICAL BLADE, SLOW SPEED MIXING, HIGHER VISCOSITIES

The Helical blade is very effective at both mixing and moving high viscosity materials. These blades are custom made to fit the vessel and can also have scraper blades on the sizes and bottom. There are multiple designs for single, dual, triple and quadruple shafts. They are expensive but work incredibly well. This will add a lot more surface area that will need to be cleaned. Most machines built to handle this style blade can reverse direction so that the blade can pump down to feed powders and pump up to help remove air.

TYPE 27: ANCHOR

The Anchor blade can be used as shown or have additional vertical resistant bars to be made into what is called a Gate blade. This blade is excellent for moving high viscosity material in a radial direction and also good for keeping the outer areas of the batch in motion.

TYPE 28: MULTI LAYER RING STYLE

A copy cat of the D blade but more limited sizes. Also known as a Ring Blade, this impeller consists of three plates welded together with “cutting teeth” in between. Provides excellent shear using the Venturi principal. Requires a 5800 fpm +/- 5% tip speed. Trial sizes available.
Rules for the D blade:

• 1/2 – 1 full blade diameter off bottom with minimum of 2 blade diameters of fluid above the blade.
• Most expensive blade but provides energy close to that of a rotor stator
• Can be challenging to clean
• Can clog with large agglomerates
• Works in one direction only
• Blade size should be ¼-1/3 diameter of tank for standard materials; higher viscosities can use up to 40% the diameter of tank.
• Viscosity Range: 1,000 CPS to 10,000 CPS. It has been used up to 50,000 CPS and lower than 1,000 CPS depending upon specific gravity
• Does not require stiffening plates
• 5800-6000 fpm +/- 5% tip speed
• Confirm the disperser can travel at tip speeds this high

TYPE 29:  PIVOT

The Pivot impeller is designed to fit through small openings like a Type 17 but is not required to open up while rotating. It opens as soon as it moves past the narrow restriction. Initial designed to be for laboratory flasks, larger sizes are now available.

TYPE 35: LMF

The LMF impeller is a very effective mixing blade that can be used with a high speed disperser.  The movement mixes the product evenly from top to bottom and side to side lifting from the bottom and sucking back down to the bottom.  Excellent for homogenous mixing with minimal air on faster speeds.

TYPE 41: HOBART STYLE GATE

This flat beater’s cut-out design allows for more efficient, smoother mixing operation. Made of cast aluminum, this beater provides dependable constant mixing of higher viscosity materials. It is a custom built blade and available in urethane and stainless for abrasive products. It can be made for non-Hobart equipment.

TYPE 50: SHEARING DISK

• Good for shear with shear sensitive products
• Gentle; use for when product deagglomeration is required but any type of particle destruction or deformation is not tolerated
• Available in any material of construction including non-metal
• 5000-6000 fpm tip speed