Micro Tube Brush

A micro tube brush is a twisted-in-wire cleaning tool built for small internal passages. A fine wire stem holds short, fine filaments in a continuous helical pattern, creating a brush that is narrow enough to enter a small bore but flexible enough to contact the wall. The stem may be a single length of wire, a doubled loop, or a custom-ended shaft; the fill may be synthetic polymer or metal wire depending on the deposit.

In use, the operator inserts the brush into the bore and works it with a combination of push, pull, and rotating strokes. The helical filaments sweep the circumference of the hole, flex into threads and cross-drilled intersections, and capture loose debris between the filament tips. The brush is pulled back through the passage, carrying material out with it. For straight-shank versions, low-speed rotary operation is possible, but most cleaning is done by hand to preserve feel and avoid over-scoring.

The product is not a bore honing tool or a substitute for flushing. It removes attached debris and works it free; the process fluid or a cleanup flush still has to carry the loosened material out of the passage. It is also not intended for large-diameter pipe cleaning or open surface scrubbing; those jobs need a brush with a larger working face.

Dimensions below are a reference range; each brush is normally matched to a specific bore diameter, passage length, and residue. Not all combinations apply to every project.

All values in the table are typical reference ranges. For a specific project, we will set brush diameter, fill material, filament size, and stem configuration from your bore drawing or sample part.

• Hydraulic and pneumatic valve bodies — spool bores, pilot orifices, cross-drilled galleries, and seat areas after machining, deburring, or lapping; removes chips, honing compound, and assembly debris.
• Fuel system components — injector bodies, carburetor passages, nozzle tips, and metering ports; polymer fills lift varnish and carbon; wire fills cut hardened fuel deposits where surface permits.
• Precision machined parts — blind tapped holes, small sensor ports, dowel pin bores, and cooling channels in molds and tooling; removes chips before final assembly or coating.
• Medical and laboratory devices — reusable instrument channels, cannula, needle hubs, and fluid path bores; PP or nylon fills selected for low shedding and chemical compatibility with cleaning agents.
• Small engine and small arms — gas ports, firing pin channels, carburetor jets, and lube passages; long reach versions clean without complete disassembly.
• Additive manufacturing and microfluidics — support material residues in internal channels, manifolds, and small manifold bores; near-size polymer fill protects as-printed surface roughness.

Start with the bore, not the part name

Measure minimum internal diameter, bore depth, and any cross holes, undercuts, tapers, or blind ends. Brush OD is selected against the smallest accessible diameter; oversize is based on nominal bore ID, not core diameter. Use pin gages to confirm.

Match the filament to the residue and the finish requirement

• Polymer fill (nylon, PBT, PP): light films, oils, coolants, powder, soft varnish; preserves fine machine finishes; use near-size or 5–20% oversize.
• Brass fill: soft metal deposits, light scale, carbon; good for aluminum or brass bores without deep scoring; use lower interference.
• Stainless steel fill: hard deposits, rust, carbon, polymer contamination; use when bore material is steel and scratching is acceptable.
• Carbon steel fill: maximum aggression on ferrous parts; avoid stainless or aluminum unless a secondary finish is acceptable.
• Abrasive nylon: surface preparation or stubborn coating removal; test on a scrap part first.

Choose stem and end style for access

Single stem for straight push-pull; double stem for better torque and durable gripping; loop or ring for hanging or lanyard retention; threaded ferrule for attaching to a rod or machine; flexible extension for curved access into manifolds. Ensure overall length leaves enough grip outside the part.

Consider hand vs. rotary operation

Hand strokes give feedback and are preferred for precision bores. For rotary cleaning, choose a straight-shank version with balanced fill, low speed, and confirm the fill will not flare. Wire fill at high speed can score the bore or throw broken wire strands.

When a micro tube brush is the wrong tool

If the passage ID is under 1 mm or the entry is very small, use a pipe-cleaner swab, chemical flush, or ultrasonic cleaning. If the bore has a precision finish that cannot tolerate any contact, use non-contact cleaning. If the job is large internal surfaces or pipe scale, select a larger tube brush with heavier fill. If the residue is welded or baked-on and the substrate is soft, hot solvent or chemical cleaning may be safer than aggressive wire brushing.

Micro tube brushes are made to the bore, not sold as a fixed one-size product. Provide the bore ID and length, cross hole locations and sizes, surface finish target, residue type, cleaning chemical, temperature, and preferred interface. A drawing, CAD file, or sample part shortens the process.

• Brush geometry: diameter, section length, overall length, trim shape (straight cylinder, taper, stepped, end tuft, or contoured profile).
• Fill system: filament material (nylon, PBT, PP, wire metals, abrasive nylon), filament diameter, density, helical pitch, and oversize amount.
• Stem and end style: single or double stem, loop, ring, threaded ferrule, flexible extension; material (304 stainless steel, brass, or coated); stiffness and length.
• Handle/interface: molded grip, extended handle, hex shank or straight shank for rotary, marking or ID color.
• Packaging and marking: bulk, individually bagged, color-coded lots, customer part number printing on packaging.
• Project support: material declarations, inspection reports, third-party testing, or project-specific documentation can be supported during the customization process.