Food grade bronze bushing
Food grade bronze bushing
Bronze Self-Lubricating Bearings for Food-Machinery Enclosed, Non-Food-Contact Drive Components
Self-lubricating bronze bushings and guide bushes for the enclosed, non-food-contact drive sections of food and beverage processing and packaging machinery.
Food and beverage production lines contain many moving parts that need reliable guidance and low friction, yet sit in locations where oil or grease is undesirable. This page covers bronze self-lubricating bearings used in the enclosed, non-food-contact drive sections of that equipment — gearboxes, drive shafts, linkages, cam and lever pivots, conveyor and packaging-machine guides. These parts are physically isolated from the product zone, so they reduce the risk of lubricant reaching food without being presented as food-contact components.
Where these bearings are used
In food and beverage machinery, self-lubricating bronze bearings are applied in positions that are enclosed and separated from the product:
- Gearbox and transmission internals — shafts, countershafts, and pivot points inside sealed housings.
- Drive shafts and couplings — support bearings in enclosed driveline assemblies.
- Linkages, cams, and levers — pivots on fillers, cappers, labellers, and depositors.
- Conveyor and packaging-machine guides — enclosed guide and slide surfaces away from the product path.
- Frame pivots and lift mechanisms — structural pivots on enclosures and guarding.
Why self-lubricating bronze in enclosed drive zones
- No external lubrication task. Graphite or other solid-lubricant plugs transfer a film to the shaft, so there is no scheduled greasing that could leak into the machine envelope.
- Reduced contamination risk in enclosed zones. Removing oil and grease eliminates a leakage source inside sealed drivetrains.
- Tolerance of dust, moisture, and temperature. Solid-lubricant films remain effective where liquid lubricants would wash out, carbonize, or degrade.
- Lower maintenance load. Fewer lubrication points reduce downtime on lines that run continuously.
Material selection by zone
Select the alloy against the actual duty and the customer’s material specification. The table below separates leaded alloys (where the spec permits, for enclosed non-contact parts) from lead-reduced options.
| Application zone | Recommended alloy | Lead content (typical) | Note |
|---|---|---|---|
| Enclosed, non-contact; spec permits leaded bronze | C93200 (SAE 660) bearing bronze | Pb 6.0–8.0% (ASTM B505/B271) | Label as non-food part; not for food contact |
| Enclosed, non-contact; high-lead spec where specified | C93700 / C93800 high-lead tin bronze | Pb 8–15% (per grade) | Only where the drawing or spec requires it |
| Stricter spec / lead-reduced preference | C95400 aluminum bronze | Pb ≤0.05% | Good strength and corrosion resistance |
| Stricter spec / lead-reduced preference | C86300 manganese bronze | Pb ≤0.20% | High strength, heavy-load, low-speed |
| General lead-reduced option | CW459K phosphor bronze / CuSn12 | Low lead | Wear resistance, moderate loads |
Graphite is used as the solid lubricant in plug form. Where incidental contact is a consideration, discuss food-grade solid-lubricant and surface-treatment options with the supplier and validate against your specification.
Standards and fit references
- Guide bushes:
DIN 9834/ISO 9448 - Plain bearings / bushes:
ISO 3547/DIN 1850 - Continuous-cast bronze:
ASTM B505/ASTM B271
Typical counterface: hardness ≥ HRC 50, surface roughness Ra 0.4–0.8 µm. Plug coverage is commonly around 25–30% of the running area; exact density and pattern are set by load, speed, and motion type.
Selection checklist
- Confirm the zone. Is the bearing enclosed and physically separated from food? If not, this page does not apply — specify a certified food-contact material instead.
- Define the duty. Radial/axial load, speed (PV), motion type (rotary / linear / oscillating), and environment (temperature, washdown, chemicals).
- Pick the alloy. Leaded C93200 for enclosed non-contact where permitted; lead-reduced C95400 / C86300 / phosphor bronze for stricter specs.
- Confirm dimensions and standard. Match DIN 9834 / ISO 9448 (guide bushes) or ISO 3547 / DIN 1850 (plain bushes) as required.
- Validate the counterface. Hardened shaft ≥ HRC 50, Ra 0.4–0.8 µm.
FAQ
Can these bearings be used in food contact?
No. The bearings on this page are for enclosed, non-food-contact positions. They are not presented as food grade or food safe. For any part that contacts food or its overspray, specify a validated food-contact alloy and obtain the applicable certification.
What if contact or overspray is possible?
Use a lead-reduced grade (for example C95400 or C86300), apply the required surface treatment, and select a certified food-contact alloy where the specification demands it. Confirm with the equipment manufacturer and your compliance function.
Do these contain lead?
Some grades do. C93200 contains about 6–8% lead; high-lead grades contain more. Lead-reduced grades such as C95400 (Pb ≤0.05%) and C86300 (Pb ≤0.20%) are available where the specification requires lower lead content.
self-lubricating Bronze Bushings & Bearings for Food Processing
BearingFace: self-lubricating bronze bushings Solutions for Food machinery
The bronze bearings in the food and beverage industry offer a competitive edge. Choose high-quality bearings to enhance your operations. Contact us for bronze bearing solutions, including specialized options for bakery equipment that requires frequent sanitation.
