This page covers contact-type lubrication brushes for chains, gears, and conveyors: flat, round, roller, and through-flow types applying oil directly to a moving part, fed from a reservoir or metering pump. It explains configuration and bristle selection, mounting, oil pressure, speed limits, and adjustment. Spray and nozzle lubrication are out of scope; the reservoir page covers oil storage and gravity feed.
Four Brush Configurations
Flat brushes, 25 – 100 mm wide, should nearly cover the chain width. Round brushes, 25 – 28 mm diameter, mount compactly from the side, aimed at the inner link plates and rollers. Roller brushes rotate continuously, motor or chain driven. Through-flow brushes have internal oil channels feeding the bristle root; 70 – 100 mm wide versions suit precise metering.
| Configuration | Size Range | Role |
|---|---|---|
| Flat | 25 – 100 mm wide | Covers the chain width |
| Round | 25 – 28 mm diameter | Compact side mounting |
| Roller | Motor or chain driven | Continuous application |
| Through-Flow | 70 – 100 mm wide | Metering at the bristle root |
Bristle Materials and Temperature Limits
Nylon PA6 and PA6.6 work to 80°C and stay flexible while holding oil. Crimped nylon covers up to 120°C and carries oil well. Brass handles 200°C in dusty, abrasive air. Stainless steel covers 300 – 350°C for kiln heat and washdown areas. Short 15 – 20 mm bristles suit fine chains; 28 – 45 mm bristles suit large-pitch chains.
| Bristle | Limit | Notes |
|---|---|---|
| Nylon PA6 / PA6.6 | 80°C | Flexible, holds oil |
| Crimped nylon | 120°C | High-speed chains |
| Brass | 200°C | Dust and abrasion |
| Stainless steel | 300 – 350°C | Kiln heat, washdown |
Mounting Position and Contact Depth
Mount on the lower inner surface of the slack (return) strand; centrifugal action helps oil enter the pin and bushing instead of being thrown off. Contact penetration should not exceed 2 mm; deeper pressure adds wear without improving lubrication. Spring-loaded mounting keeps contact pressure steady as bristles shorten.
Oil Supply and Pressure
The brush only needs steady wetting. Typical supply is 0.5 – 2 bar (7 – 30 psi) at a few drops per minute, set by a sight-feed valve or metering pump; gravity feed from an elevated reservoir is usually enough, as covered on the reservoir page. From supply point to brush, 6×1.5 mm polyamide tube is the feed line. Higher pressure only mists and wastes oil.
Chain Speed and Contamination
Standard bristles suit chain speeds up to about 1 m/s (60 m/min); above that, crimped nylon or stainless steel bristles hold oil better, or use a roller brush. In heavy contamination (mining, agriculture, sticky residue), add a cleaning brush ahead of the lubricating brush.
Installation and Adjustment
Inlet threads: M8x1, G1/4, G1/8, 1/8″ BSP, and 1/8″ NPT; state yours when ordering so the fitting matches. For #40 – #50 chains, start with a 25 mm wide brush. Tighten by hand, add 1/4 turn with a wrench, run 1 hour, then re-check adjustment.
What Is Supplied
Each set includes the brush body, a mounting bracket with an adjusting screw, an oil fitting matched to your specified thread, and installation instructions. Confirm thread, width, and bristle material when ordering.
Honest Limits
Contact brushes have real boundaries:
- They apply oil by contact; spray or nozzle lubrication belongs to a different family.
- They meter small flows, not the large volumes of circulation systems.
- Bristles wear; plan periodic inspection and replacement, not a fixed interval.
- Above 1 m/s, standard bristles lose effectiveness; use crimped or stainless bristles, or a roller brush.
Share chain size, speed, temperature, and thread, and request a quote with your chain details.
Frequently Asked Questions
How do I choose among the four configurations?
Match space and coverage: flat for full width, round for side mounting, roller for continuous rotation, through-flow for metering at the root. For the supply side, see the reservoir page.
Which bristle material fits my temperature?
Nylon PA6 or PA6.6 to 80°C, crimped nylon to 120°C, brass to 200°C in dusty abrasion, stainless steel at 300 – 350°C for kiln heat and washdown.
Where should the brush sit on the chain?
Lower inner surface of the slack (return) strand; centrifugal action helps oil enter the pin and bushing. Flat nearly covers the chain width; round aims at the inner plates and rollers.
How much oil pressure does the brush need?
0.5 – 2 bar (7 – 30 psi) at a few drops per minute, set by a sight-feed valve or metering pump; gravity feed from an elevated reservoir is often enough.
What changes on high-speed chains?
Standard bristles suit up to about 1 m/s (60 m/min). Above that, choose crimped nylon or stainless steel bristles, or a roller brush.
How do I match the inlet thread?
M8x1, G1/4, G1/8, 1/8″ BSP, and 1/8″ NPT are offered; state yours when ordering so the fitting matches.
How deep should the brush press into the chain?
No more than 2 mm; deeper pressure does not improve lubrication and accelerates wear. Spring-loaded mounting holds steady contact as bristles shorten.
How do I know when to replace the bristles?
Spring-loaded mounting compensates for gradual wear. Inspect routinely and replace when bristles no longer hold oil across the width or touch the chain evenly.
What about heavy contamination?
Add a cleaning brush ahead of the lubricating brush so oil penetrates clean metal.
Who is IsoHiTech?
IsoHiTech Lubrication Systems is a lubrication equipment supplier founded in 2023, engineering since 2006. Send your chain size, speed, temperature, and thread to inquiry@isohitech.com, or ask our team for a configuration review.
