Model: 8274-4
The 8274-4 is the only grinder on the market offering 3 HP at 115 volts while operating at a 230-volt level. With variable speed and a soft start to control its amperage draw, the 8274-4 adjusts to the needs of small or large jobs. This machine is well suited for removal of thin-set, coatings, adhesive, prepping concrete for overlays or coatings, and polishing.
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Standard | Metric |
---|---|---|
Width | 20" | 51 cm |
Disc Size | 18.5" | 47 cm |
Max. Height | 52" | 132 cm |
Min. Height | 27.5" | 70 cm |
Max. Length | 75" | 191 cm |
Weight | 388 lb | 176 kg |
Motor RPM | 1740 | |
Voltage | 115 | |
Frequency | 60 Hz | |
HP | 3 | 2.24 kW |
Amps | 15 or 20 - controller can switch between both settings | |
Drum RPM | 133.8 | |
Motor Phase | Single |
Part # | Name | Standard | Metric | Description | Fits | ||
---|---|---|---|---|---|---|---|
9555 | 9555 2-UP PCD- MICRO | Designed for aggressive concrete stock removal as well as coatings, glues, mastics, and other floor covering adhesives. PCDs and carbides can be used with all National planetary grinder machines. Remove heavy stock, adhesive, thin set, and epoxies |
HELIX, 8274-4 | ||||
9556 | 9556 2-UP PCD- 1/2 ROUND | Designed for aggressive concrete stock removal as well as coatings, glues, mastics, and other floor covering adhesives. PCDs and carbides can be used with all National planetary grinder machines. Removes heavy stock, adhesive,thin set, and epoxies |
HELIX, 8274-4 | ||||
9557 | 9557 4-UP PCD- MICRO | Designed for aggressive concrete stock removal as well as coatings, glues, mastics, and other floor covering adhesives. PCDs and carbides can be used with all National planetary grinder machines. Removes heavy stock, adhesive, thin set, and epoxies |
HELIX, 8274-4 | ||||
7268-2 | 7268-2 CARBIDES | Designed for aggressive concrete stock removal as well as coatings, glues, mastics, and other floor covering adhesives. PCDs and carbides can be used with all National planetary grinder machines. Removes coatings, glues, thin set, and thin mastics |
HELIX, 8274-4 |
Part # | Name | Standard | Metric | Description | Fits | ||
---|---|---|---|---|---|---|---|
9522-50 | 9522-50 BRAZED TRAPEZOID DIAMOND | 50 Grit: Prep concrete for reapplication and polishing. Used primarily in light industrial and residential applications for concrete grinding and profiling as well as sealer and top coat removal. Provide excellent surface profiles for new coatings, epoxies, or stains. Also create exceptional profiles for concrete preparation and restoration prior to polishing concrete. Brazed trapezoids can be used with all National planetary grinders. |
HELIX, 8274-4 | ||||
9507-30 | 9507-30 METAL BOND DIAMOND - HALF BAR | 30 Grit: Remove sealers and preps concrete for polishing. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9235-50 | 9235-50 5-INCH BRAZED DIAMOND | 50 Grit: Create a "broom finish" on soft concrete surfaces; first stage to polishing concrete. Used primarily in industrial applications for medium to aggressive concrete grinding and profiling as well as sealer and top coat removal. Perfect for concrete preparation and restoration prior to concrete polishing. In addition, brazed diamonds effortlessly remove stains and imperfections from exterior wood decking while simultaneously profiling wood for receiving new stains and/or sealers. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9508-30SB | 9508-30SB METAL BOND DIAMOND - FULL BAR | 30 Grit: Remove various coatings, and profiles on HARD concrete only. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9235-100 | 9235-100 5-INCH BRAZED DIAMOND | 100 Grit: Create a "broom finish" on soft concrete surfaces; first stage to polishing concrete. Used primarily in industrial applications for medium to aggressive concrete grinding and profiling as well as sealer and top coat removal. Perfect for concrete preparation and restoration prior to concrete polishing. In addition, brazed diamonds effortlessly remove stains and imperfections from exterior wood decking while simultaneously profiling wood for receiving new stains and/or sealers. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9522-16 | 9522-16 BRAZED TRAPEZOID DIAMOND | 16 Grit: Remove paint, stain, and sealers; preps concrete for reapplication. Used primarily in light industrial and residential applications for concrete grinding and profiling as well as sealer and top coat removal. Provide excellent surface profiles for new coatings, epoxies, or stains. Also create exceptional profiles for concrete preparation and restoration prior to polishing concrete. Brazed trapezoids can be used with all National planetary grinders. |
HELIX, 8274-4 | ||||
9507-30HB | 9507-30HB METAL BOND DIAMOND - HALF BAR | 30 Grit: Remove various coatings, and profiles on SOFT concrete only. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9522-30 | 9522-30 BRAZED TRAPEZOID DIAMOND | 30 Grit: Prep concrete for reapplication and polishing. Used primarily in light industrial and residential applications for concrete grinding and profiling as well as sealer and top coat removal. Provide excellent surface profiles for new coatings, epoxies, or stains. Also create exceptional profiles for concrete preparation and restoration prior to polishing concrete. Brazed trapezoids can be used with all National planetary grinders. |
HELIX, 8274-4 | ||||
9507-6 | 9507-6 METAL BOND DIAMOND - HALF BAR | 3 Grit: Remove thin epoxy, paint, adhesives and sealers. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9510-30 | 9510-30 METAL BOND DIAMOND - PROFILING DIAMOND | 30 Grit: Prep high-/moderate-density concrete for reapplication. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9508-16 | 9508-16 METAL BOND DIAMOND - FULL BAR | 16 Grit: Remove epoxy as well as heavy and light sealers. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9522-100 | 9522-100 BRAZED TRAPEZOID DIAMOND | 100 Grit: Prep concrete for polishing. Used primarily in light industrial and residential applications for concrete grinding and profiling as well as sealer and top coat removal. Provide excellent surface profiles for new coatings, epoxies, or stains. Also create exceptional profiles for concrete preparation and restoration prior to polishing concrete. Brazed trapezoids can be used with all National planetary grinders. |
HELIX, 8274-4 | ||||
9508-16SB | 9508-16SB METAL BOND DIAMOND - FULL BAR | 16 Grit: Remove various coatings, and profiles on HARD concrete only. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9510-50 | 9510-50 METAL BOND DIAMOND - PROFILING DIAMOND | 50 Grit: Prep concrete for polishing. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9507-12 | 9507-12 METAL BOND DIAMOND - HALF BAR | 12 Grit: Remove thin epoxy, paint, adhesives and sealers. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9508-30 | 9508-30 METAL BOND DIAMOND - FULL BAR | 30 Grit: Remove light sealers. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9235-16 | 9235-16 5-INCH BRAZED DIAMOND | 16 Grit: Remove thin epoxy, paint, stain, adhesives, and heavy sealers. Used primarily in industrial applications for medium to aggressive concrete grinding and profiling as well as sealer and top coat removal. Perfect for concrete preparation and restoration prior to concrete polishing. In addition, brazed diamonds effortlessly remove stains and imperfections from exterior wood decking while simultaneously profiling wood for receiving new stains and/or sealers. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9507-16 | 9507-16 METAL BOND DIAMOND - HALF BAR | 16 Grit: Remove thin epoxy, paint, adhesives and sealers. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9235-30 | 9235-30 5-INCH BRAZED DIAMOND | 30 Grit: Remove adhesives, heavy and light sealers. Used primarily in industrial applications for medium to aggressive concrete grinding and profiling as well as sealer and top coat removal. Perfect for concrete preparation and restoration prior to concrete polishing. In addition, brazed diamonds effortlessly remove stains and imperfections from exterior wood decking while simultaneously profiling wood for receiving new stains and/or sealers. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9510-120 | 9510-120 METAL BOND DIAMOND - PROFILING DIAMOND | 120 Grit: Prep concrete for polishing. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9504-25 | 9504-25 METAL BOND DIAMOND - SUPER SOFT, SINGLE BAR DIAMOND INSERT | 25 Grit: Extremely aggressive coating removal with supersoft matrix for hard concrete or heavy cure and seal treatments, perfect for breaking surface tension. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 | ||||
9507-16HB | 9507-16HB METAL BOND DIAMOND - HALF BAR | 16 Grit: Remove various coatings, and profiles on SOFT concrete only. Used for light, medium, and aggressive concrete grinding and profiling as well as sealer and top coat removal. Can be used for both residential and industrial applications. Perfect for leveling concrete high spots and repairing imperfections as well as creating the perfect profile for accepting new coatings and epoxies, or preparing concrete for polishing. Metal bond diamonds can be used with all National planetary and passive planetary grinders. |
HELIX, 8274-4 |
Part # | Name | Standard | Metric | Description | Fits | ||
---|---|---|---|---|---|---|---|
9267-3000 | 9267-3000 5-INCH POLISHING PAD | 3000 Grit: Follow 9267-1500 to create a "mirror" polished concrete. Used for polishing concrete to various finishes and shines. Resin bond. Available in escalating grits. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9267-800 | 9267-800 5-INCH POLISHING PAD | 800 Grit: Follow 9267-400 to create a "shine" polished concrete. Used for polishing concrete to various finishes and shines. Resin bond. Available in escalating grits. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9245 | 9245 VELCRO ADAPTER | Mounts onto the 9241 quick-change magnetic assembly for using polishihng pads and brazed disks. Three adapters are required. |
8274-4 | ||||
9267-50 | 9267-50 5-INCH POLISHING PAD | 50 Grit: Achieve a "no reflection" polished concrete. Used for polishing concrete to various finishes and shines. Resin bond. Available in escalating grits. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9267-1500 | 9267-1500 5-INCH POLISHING PAD | 1500 Grit: Follow 9267-800 to create a "high shine" polished concrete. Used for polishing concrete to various finishes and shines. Resin bond. Available in escalating grits. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9267-100 | 9267-100 5-INCH POLISHING PAD | 100 Grit: Follow 9267-50 to create a "little reflection" polished concrete. Used for polishing concrete to various finishes and shines. Resin bond. Available in escalating grits. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9267-200 | 9267-200 5-INCH POLISHING PAD | 200 Grit: Follow 9267-100 to create a "moderate reflection" polished concrete. Used for polishing concrete to various finishes and shines. Resin bond. Available in escalating grits. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 | ||||
9267-400 | 9267-400 5-INCH POLISHING PAD | 400 Grit: Follow 9267-200 to create a "satin reflection" polished concrete. Used for polishing concrete to various finishes and shines. Resin bond. Available in escalating grits. These polishing pads are for use with all National planetary grinders. |
HELIX, 8274-4 |
Part # | Name | Standard | Metric | Description | Fits | ||
---|---|---|---|---|---|---|---|
9292 | 9292 FLOATING HEAD ASSEMBLY | Improve machine performance, reach low spots, and level high spots by following surface undulation |
8274-4 | ||||
9241 | 9241 QUICK-CHANGE MAGNETIC-MOUNT ASSEMBLY | Three assemblies and three 73250 tooling holder mounting screens are required |
8274-4 | ||||
9521 | 9521 CARBIDES & TOOLING HOLDER | Designed for aggressive concrete stock removal as well as coatings, glues, mastics, and other floor covering adhesives. PCDs and carbides can be used with all National planetary grinder machines. Use to attach the above tooling to National's grinders |
HELIX, 8274-4 | ||||
9550 | 9550 SCREW | Designed for aggressive concrete stock removal as well as coatings, glues, mastics, and other floor covering adhesives. PCDs and carbides can be used with all National planetary grinder machines. Use to attach tooling to the above holder |
HELIX, 8274-4 | ||||
6280-401B | 6280-401B 7/32 T-HANDLE WRENCH | 7/32" T-HANDLE WRENCH |
8274-4 | ||||
401882 | 401882 MORFLEX COUPLERS | 8274-4 | |||||
8270 | 8270 CONCRETE HARDNESS TESTER | Unlike other mineral hardness testing tools, the 8270 is made of metals and alloys of hardness values equal to 2 through 9 on the Mohs hardness scale, so they can be easily ground to sharp points that will not break off. Set includes 8 points, streak plate for testing color, hardness plates (3.5 and 5.5), magnet for detecting magnetic rock, grindstone to keep points sharp, hardness tables, and instructions, all in a compact wooden case. |
HELIX, 8274-4 |
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