20mm P320 AO Tube Brush

A 20mm P320 AO Tube Brush is a cylindrical abrasive brush designed for internal cleaning and surface conditioning of tubes, ports, and machined bores. “AO” stands for aluminum oxide, the abrasive mineral loaded into the nylon filaments. “P320” is the grit size, a fine grade that removes thin films and light deposits without aggressive stock removal.

In use, the brush is inserted into the opening and either manually stroked or driven at low speed. The abrasive-loaded nylon filaments conform to the tube wall and scrub away scale, rust, carbon, powder, and process residues. The stainless steel core provides axial stiffness so you can apply pressure without the head folding over, while the threaded end allows extension or mechanical drive.

This is not a heavy descaling tool. Use low RPM if powered, and avoid temperatures above 150 °C (302 °F) to prevent nylon softening. The brush follows gentle curves, but tight elbows may require a more flexible core configuration.

The 20 mm diameter is the nominal outside diameter of the brush. In use, the abrasive nylon filaments compress slightly to create an interference fit inside a tube whose ID is close to 20 mm. If your actual bore is significantly different, we can adjust trim length, filament stiffness, or overall diameter. The threaded connection can be specified to match your extension rod or rotary drive.

• Heat exchanger tube internal cleaning: removes light scale, rust, and process film from tube IDs before inspection, hydrotesting, or retubing.
• Hydraulic and pneumatic ports: cleans internal walls, threads, and cross holes without leaving loose metal particles.
• Machined bores and blind holes: reaches the bottom of a 20 mm bore to remove chips, coolant residue, and light oxidation after machining.
• Threaded fittings and adapters: cleans thread roots without damaging the thread profile, which matters for sealing surfaces.
• Surface preparation for coating, plating, or adhesive: P320 grit creates a uniform surface texture that improves bond strength.

This 20 mm P320 AO tube brush fits a specific set of jobs. Check these points before ordering:

1. Measure the tube ID. The brush works best in bores with an internal diameter between approximately 19 and 22 mm, depending on filament flexibility and the interference fit you want. A smaller bore will not allow entry; a larger bore will give only partial contact. For other diameters, ask for a different OD or trim length.
2. Evaluate the deposit. P320 is fine grit, designed for light scale, surface rust, carbon films, and process residues. If you are dealing with heavy mill scale, thick rust, or baked-on carbon, use a coarser grit (P80–P180) or a stainless or carbon steel wire brush. P320 will polish rather than remove heavy deposits.
3. Check the reach. The head is 100 mm long and the handle adds 200 mm. If you need to clean a tube deeper than about 300 mm, use a threaded extension or specify a longer handle. For very deep or highly curved tubes, consider a twisted wire core brush or a flexible shaft tool.
4. Decide on motion. For manual use, the 9 mm grip diameter gives comfortable hand control. For powered use, the threaded connection allows mounting in a low-speed drill or rotary tool; keep speed below 600 RPM and avoid continuous heat build-up. Abrasive nylon softens near 150 °C.
5. Consider the environment. The 304 stainless handle handles water, coolants, and mild chemicals. For strong acids, chlorides, or high-humidity environments, we can quote a 316 stainless or coated handle.

When to choose a different brush: Use a wire brush for hard scale or weld spatter, a smaller diameter for bores under 19 mm, a larger diameter for bores over 22 mm, a brass or steel brush for temperatures above 150 °C, or a flexible spiral brush for tight bends. This abrasive nylon tube brush is for fine surface conditioning and light deposit removal, not heavy stock removal.

Every tube cleaning job has a specific bore, deposit, and access condition. We can adjust this brush to match your project. Common changes include:

• Brush diameter: from 15 to 30 mm or custom OD, with trim length adjusted for the right interference fit.
• Brush head length: shorter or longer than 100 mm to match the tube section you need to clean.
• Handle length and grip diameter: standard 200 mm x 9 mm, or custom dimensions for deeper reach or ergonomic needs.
• Thread size and type on connection: M6, M8, 1/4-20, or your specified thread for extension rods or rotary tools.
• Bristle material and grit: P320 is standard; other grits such as P80, P120, P180, P240, P400, or P600 are available. Silicon carbide or ceramic abrasive nylon can be specified for harder surfaces.
• Handle material: 304 stainless is standard; 316 stainless, coated steel, or non-metallic options for specific chemical environments.
• Filament density and stiffness: adjust fill density, filament diameter, and trim length to control cleaning pressure and conformability.
• Color coding and marking: custom color, laser marking, or pad printing for identification in multi-brush operations.
• Packaging: bulk, individually bagged, or project-specific packing.

To define the custom configuration, provide tube ID and tolerance, tube length, deposit type and thickness, wet or dry use, chemical exposure, manual or powered drive, and any spindle or extension interface. A drawing or sample tube speeds up the specification. If your project requires material certifications, inspection reports, or third-party testing, we can coordinate those during the specification phase.