What does a correctly sized tube brush do?
It touches the whole inside wall without jamming, folding over or leaving clean and dirty bands. Get the brush diameter right for the bore first. Then set the brush-section length, the stem, the tip, the fill and the drive for the shape of the passage and the deposit in it.
What sizes are tube brushes made in?
The published ranges below cover the common constructions. Sizes are given in inches, as they are published.
| Construction | Published range | Use |
|---|---|---|
| Single stem, single spiral | Brush diameter 1/8–2 in; brush section 1–5 in; overall length 6–16 in | Hand use and light internal cleaning |
| Double stem, powered | Brush diameter 1/4–2 in; brush section 1–3 in; overall length 4–5.5 in | More torsional strength and denser powered cleaning |
| Abrasive nylon tube brush | Diameter 1/4–1.75 in; grit 80–500; 600 grit in some fine constructions | Deburring, oxide removal, thread and bore finishing |
| Flue and large-pipe brush | Diameter 1–16 in, with threaded connector and extension rods | Large pipes, flues and long runs |
How much bigger than the bore should the brush be?
It depends on the job, so decide the job first. For loose dust and wiping, choose a brush close to the bore size: the tips reach the wall and bend only a little. For scrubbing, choose a brush larger than the bore so the filament bends against the wall and does the work. Long, fine polymer filament takes more oversize than short, coarse wire, which jams.
Instrument channels are a separate case. STERIS publishes a sizing rule for them: measured channel diameter plus 3 mm, and channel length plus 5 cm. That rule is written for channel brushes on medical instruments. Do not carry it over unchanged to rigid industrial bores.
How does the shape of the passage change the brush?
| Passage | What to build |
|---|---|
| Blind hole | A fan, radial or protected tip, so the bottom gets cleaned without a cut stem end scraping it |
| Cross hole or port intersection | Abrasive nylon or side tufts that reach the edge where the holes meet |
| Long straight tube | Threaded connector, extension rods, cable or a powered tube-cleaning system |
| Curved hose or several bends | Flexible stem, pull-through cable or a cleaning pig, not a rigid stem |
| Stepped or mixed diameter | Tapered, dual-diameter or staged brush section |
Which fill suits which deposit?
Fine PA612 or PBT for soft wiping and wet cleaning. Polypropylene where the chemicals vary. Stainless steel for hard cleaning where corrosion matters. Carbon steel for low-cost rust and scale removal on steel parts. Brass or phosphor bronze when the wire must be softer than the part. Abrasive nylon for controlled cutting without loose wire fragments in the bore.
What should you send for a quote?
The smallest and largest bore diameter, the passage length, any bends and steps, the shape of the bottom and the surface finish. Then the deposit, hand or powered use and speed, which end you reach from, the stem or thread you need, temperature and fluid, and the quantity. A section drawing of the passage answers most of this at once.
