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Northrock Ceiling Grinder Parts
About Northrock Ceiling Grinder Parts
Every replacement part for the Northrock PRO 1200 overhead concrete grinder, in both the Electric and Gas configurations. Grinding heads, flexible shafts, power units, masts, and dust-control vacuums, shipped from an authorized Northrock supply channel.
The Northrock PRO 1200 is the industry standard tool for removing form marks, seams, and surface imperfections from poured concrete ceilings, with the operator working entirely from the floor. A heavy-duty winch raises and lowers the mast to fit ceiling heights ranging from 7 to 12 feet, while a multi-axis pivot on the grinding head self-contours to the surface to prevent gouging. The PRO 1200 is offered in two power configurations, the PRO-1200 Electric for indoor sites with a 115V or 220V outlet, and the PRO-1200G Gas for outdoor or unwired sites with a 4 HP Honda engine. The PRO-1200V dust-control configuration adds a vacuum guard with brush seals and pairs with a HEPA cart for OSHA silica-dust compliance.
DanseUSA is an authorized Northrock dealer stocking the full PRO 1200 OEM parts catalog, from the complete grinding head assembly (25AM1) and electric power unit (555B3) or gas engine assembly (555C3) down to individual ball bearings, brush guards, and hardware. Every part number on this page matches the official Northrock PRO 1200 / PRO 1200V instruction manual.
Looking for variant-specific parts? Browse PRO-1200 Electric Ceiling Grinder Parts or PRO-1200G Gas Ceiling Grinder Parts. For the full Northrock equipment catalog, see our Northrock Parts hub.
| Specification | Detail |
|---|---|
| Electric Power Unit | 1.5 HP Baldor motor, 115V or 220V (P/N 555B1, complete assembly 555B3) |
| Gas Power Unit | 4 HP Honda gas engine (P/N 555C1, complete assembly 555C3) |
| Ceiling Reach | 7 ft to 12 ft, adjustable via manual winch |
| Grinding Head Thread | 5/8"-11 R.H. spindle, accepts standard concrete grinding stones |
| Drive System | 7 ft flexible shaft with rubber-coated steel braid casing (P/N 30AK7) |
| Pressure System | Spring-loaded cam-lock tension handle for constant, even ceiling contact |
| Head Design | Multi-axis pivot bearing, self-contours to ceiling surface |
| Mobility | Solid rubber tires with rear swivel caster |
| Dust Control Option | PRO-1200V configuration adds vacuum guard with brush seals, paired with single vacuum or dual-vacuum HEPA cart for OSHA silica compliance |
The PRO 1200 is documented as 12 sub-assemblies in the Northrock service manual. The grinding head, guard, flexible shaft, frame, mast, and vacuum sub-assemblies are shared between Electric and Gas configurations. The power unit and motor hanger are variant-specific.
Grinding Head Assembly
Shared. Spindle (155BS1), three ball bearings (140C003), inner and outer housing shells (105BG1, 105BH1), compression spring (465C1), wiper dust seal (680A1), complete head assembly (25AM1).
Guard Assembly
Shared. Vacuum guards (270E2, 270F2, 270F1, 270E3 complete), brush guards (670A1, 670B1), brush holders (495B1, 495C1), wiper dust seal (680A1), washer guard (370G1).
Electric Power Unit
Electric only. 1.5 HP Baldor motor (555B1), casing adapter (150HK2), core adapter (160ED2), power cord (505A1), electric switch (425D1), electric cord (505E1), complete assembly (555B3).
Electric Motor Hanger
Electric only. Motor plate (440M1), motor hanger (440L1), hinge pin (180D1), cotter pin (180E2), end cap (400M1).
Gas Engine Power Unit
Gas only. 4 HP Honda gas engine (555C1), core adapter (160EE2), casing adapter (150HR2), casing adapter plate (215BE1), complete assembly (555C3).
Gas Engine Hanger
Gas only. Gas engine plate (440X1), gas engine hanger (440W1), end caps (400M1), complete hanger assembly (440AH1).
Flexible Shaft Assembly
Shared. 7 ft outer casing (275Y7), 7 ft inner core (250T7), complete 7 ft shaft assembly (30AK7).
Base Frame Assembly
Shared. Base frame (440F1), swivel caster (590B1), solid rubber tires (590A1), cotter pin (180E1), end caps (400M1).
Main Frame Assembly
Shared. Main frame (440H1), handle (165D1), grips (165C1), pulley (590C1), locking knob (365B1), cable assembly (315B2), winch (595A1), tension handle (165E1), chain lug (280A222).
Mast and Cross Beam Frame
Shared. Mast (440K1), cross beam (440J2), plate with grommet (215AX2), grommet (130B1), tension spring (465B1), chain (315C1), eye bolts (570A1), hinge pin (180C1), hitch pins (180E3).
Vacuum Assembly
PRO-1200V option. Vacuum frame (440Y1), vacuum unit (645A1), guard assembly (270E3), vacuum hose (640A1), hose clamp (695A1), wiper dust seal (680A1), complete vacuum assembly (645B1).
Dual Vacuum Cart Assembly
PRO-1200V option. Cart frame (440AN1), handle (440AP1), two standard vacuums (645A1) or HEPA pair (645A2), Y hose adapter kit (640B1), four swivel casters, complete cart (645B3, HEPA 645B3H).
Based on the Northrock service manual and typical contractor wear patterns, these are the components that wear first on a PRO 1200 in regular use. All shared between Electric and Gas variants.
- Flexible shaft inner core (250T7) is the single highest-wear consumable on the unit. The Northrock manual specifies inspection and re-lubrication every 50 hours of operation. Replace the core when you see dry spots that reappear quickly after greasing, kinking along the length, or stiffness when flexed by hand.
- Grinding head ball bearings (140C003) sit inside the head and carry every grinding cycle. The head uses three of them. Replace when you hear grinding or rumbling from the head, feel lateral play in the spindle, or notice the head wandering off-true during a cut.
- Wiper dust seal (680A1) sits at the spindle on both the grinding head and the vacuum guard. Replace when dust visibly leaks past the seal during operation, since a failed seal kills suction on a PRO-1200V and lets concrete dust into the head bearings.
- Guard brush seals (670A1, 670B1) ride directly against the ceiling surface. Replace when bristles are flattened, broken, or missing in patches. Worn brushes are the most common reason a PRO-1200V loses dust capture efficiency.
- Tension spring (465B1) in the mast applies the cam-lock pressure that keeps the head against the ceiling. Replace if the head no longer holds firm pressure after the tension handle is locked, or if you have to manually push the cart to maintain contact.
- Electric switch (425D1) and power cord (505A1) on the Electric variant handle every start and stop, and they get pulled, crushed, and dragged across slabs every shift. Inspect the cord and box at every shift change.
Most structural parts are shared between Electric and Gas. The differences are concentrated in the power unit and the hanger assembly that mounts it to the frame. Confirm your model before ordering power-unit components.
| Component | PRO-1200 Electric | PRO-1200G Gas |
|---|---|---|
| Power Source | 1.5 HP Baldor electric motor (555B1) | 4 HP Honda gas engine (555C1) |
| Designated Use | Indoor environments, no exhaust | Outdoor or unwired sites, no extension cord |
| Outlet Required | 115V or 220V outlet | None, runs on gasoline |
| Casing Adapter | 150HK2 | 150HR2 |
| Core Adapter | 160ED2 | 160EE2 |
| Motor or Engine Plate | 440M1 | 440X1 |
| Motor or Engine Hanger | 440L1 | 440W1 (complete 440AH1) |
| Shared Components | Grinding head (25AM1), guard, 7 ft flexible shaft (30AK7), main frame, mast and cross beam, base frame, vacuum assemblies, all wear seals and bearings | |
Electric Motor (PRO-1200 Electric)
Keep the motor housing clean for proper cooling. Inspect the switch and both cord segments for cuts or strain damage at every shift change. Per the Northrock manual, the Baldor motor bearings are sealed and require no field lubrication. Replace the motor unit when bearings become noisy or rough.
Honda Gas Engine (PRO-1200G Gas)
Per the Northrock manual, see the engine manufacturer manual for service and maintenance requirements. Consult an authorized engine service center for any service or maintenance work. Always remove the spark plug wire and place the switch in the off position before assembly or accessory changes.
Flexible Shaft
Every 50 hours, remove the inner core on a clean surface free of dirt and grit. Inspect for dry sections. Wipe down and apply a 1/16" coating of high-quality lithium grease before reinstalling. Do not over-grease, as excess lubricant creates drag, heat, and premature shaft failure.
Operating Practice
Per the manual, never start the grinder with the head pressed to the ceiling. Always start the power unit first, then push the tension handle down to engage the cam-lock pressure. Always re-tighten the mast lock handle after every height change, and periodically check all bolts for snugness.
Need Help Identifying a PRO 1200 Part?
Share your model designation (PRO-1200 Electric, PRO-1200G Gas, or PRO-1200V dust-control configuration), serial number, and the part you are replacing. Our parts team verifies fitment against the official Northrock manual before every order ships.
Frequently Asked Questions
Match the Ref. # on the diagram to the row in the parts list at the right. Click a part name to see details, price, and add it to cart.
Confirm your model/series and serial number range on the product page. Many manufacturers have serial breaks, when in doubt, share your model and serial with us and we’ll verify fit.
The Ref. # points to the callout on the drawing. Qty shows how many of that item your machine uses. Parts are sold individually unless noted as a kit.
Yes, we supply genuine OEM parts for all our brands. If a part has an approved replacement, we ship the latest superseded revision
Manufacturers often supersede numbers. Our pages list the current orderable number and show older numbers in the description when available. Your old number will cross-reference to the correct part.
Yes. Some items are not pictured or are shared with other assemblies. Send us the model, serial, and a description (or photo) and we’ll locate it.
Yes. DanseUSA passes the manufacturer’s warranty to you. Coverage applies to defects in materials and workmanship under normal use for 30 days from the purchase date, in line with the manufacturer’s warranty policy. Terms can vary by brand; the product page reflects the applicable policy. If a claim is needed, we’ll help coordinate with the manufacturer.
Yes, most new, uninstalled items can be returned under our standard policy. Please see our Returns & Refunds Policy for eligibility, timeframes, and any exceptions.