Bronze bushings for agricultural machinery
Farm equipment shares a set of bearing conditions: shock and vibration, dust and fertiliser, months of standing still followed by weeks of continuous work, and greasing in the field when someone remembers. Cast bronze bushes suit that: they embed the dust, resist the corrosion, take grease again after a season and are cheap to replace. Machined to the OEM drawing or to the dimensions of the worn bush.
Are bronze bushings strong enough for farm machinery? A cast bronze bush carries 25 N/mm² of dynamic bearing pressure and 45 N/mm² static – more than the pivots on any tractor or implement see – and unlike a steel or plastic bush it keeps working on residual grease with grit in the joint. The default alloy is C93200 / SAE 660; gunmetal LG2 for wet and fertiliser-exposed positions; C86300 or aluminium bronze for the heavy pivots of large tillage tools.
- Tractor front axle pivots, three-point linkage, steering: C93200 sleeves and flanged bushes Ø20 – 80 mm
- Harvester header pivots, reel and auger bearings: C93200 / LG2, often flanged
- Baler plunger guides and knotter shafts: CuSn12 or C93200 with oil grooves
- Disc harrow hubs, plough turnover pivots, subsoiler shanks: C86300 / C95400 thick-wall
- Trailer steering axles and tipper cylinder eyes: C93200, greased
Where bronze bushings are used, by implement
| Implement · position | Movement | Load | Contamination | Alloy | Form and grooves |
|---|---|---|---|---|---|
| Tractor front axle pivot, steering knuckles, three-point linkage | oscillating | high, shock | dust, water | C93200 · C95400 | sleeve / flanged, G2, grease nipple |
| Combine header pivots, reel arms, auger and elevator shafts | oscillating / slow rotating | medium | dust, chaff | C93200 · LG2 | flanged, G1 / G2 |
| Baler plunger guides, knotter and needle shafts | reciprocating / oscillating fast | medium, vibration | dust, twine | CuSn12 · C93200 | sleeve, G2 / G4, oil lubricated guides |
| Disc harrow and disc plough hubs, coulter arms | slow rotating / oscillating | high, shock | soil, fertiliser | C86300 · C93200 | thick-wall sleeve, G2, sealed |
| Plough turnover, subsoiler and cultivator shank pivots | oscillating | very high, shock | soil | C86300 · C95400 | thick-wall, G8 pockets |
| Seed drill and spreader linkages, agitator drives | oscillating / rotating | low – medium | fertiliser, seed dressing | LG2 · C93200 | sleeve, G1 / G2 |
| Feed mixer and manure spreader augers | rotating slow | medium | wet, corrosive | LG2 · aluminium bronze | flanged, G3 |
| Trailer steering axles, tipper and lift cylinder eyes | oscillating | high | road salt, water | C93200 | sleeve, G2 / G4 |
Which alloy for farm equipment
C93200 / SAE 660 is the default: lowest cost of the bearing bronzes, best embeddability for dust, runs on unhardened pins and shafts, easy to replace. LG2 / C83600 gunmetal where fertiliser, manure or wash-down water attack the joint at moderate load – its zinc and tin give it better resistance to those than 660. C86300 or aluminium bronze for the heavy, shock-loaded pivots of large tillage tools and high-horsepower tractors, on hardened pins. Steel bushes on the same positions gall as soon as the grease is gone; plastic bushes crush under edge loading – which is why replacing them with bronze is routine.
Seasonal use: storage, corrosion and relubrication
A pivot that stands for six months collects moisture under the old grease; fertiliser residues (urea, ammonium nitrate, chlorides) and manure are aggressive to copper alloys and to steel pins alike. Grease every bronze bush before parking the machine so that the joint is full and the water is kept out; after washing, grease again to purge the water; at the start of the season move each joint and grease until clean grease shows. Bronze does not rust to the pin, so a bush that stood a season will move; a steel bush often will not. For spreaders and seed dressings prefer LG2 and seal the housing.
Replacement bushings in small batches
Most farm bushes are Ø15 – 100 mm and are ordered a few at a time for a dealer's shelf or a workshop job. Measure the old bush – bore at the unworn end, outside diameter, length, flange – or the housing and pin, send the numbers with a photo, and the replacement is machined to them in the right alloy with the ISO press-fit and clearance. Metric and inch, no minimum order, samples in 3 – 5 days; a drawing is welcome but not required.
For implement manufacturers
For series production the shop runs under ISO 9001 and IATF 16949 with PPAP level 3 documentation on request, machines to your drawing and tolerance classes, and delivers with a raw-material certificate and CMM report per batch when specified. Annual volumes are scheduled in batches ahead of the season; alloy stock for C93200 is kept for the common bores.
Alloy by condition
| Alloy | Choose for | Shaft / pin | Notes |
|---|---|---|---|
| C93200 / SAE 660 | general pivots, linkages, dust | plain steel | default; lowest cost |
| LG2 / C83600 | fertiliser, manure, wash-down, low – medium load | plain or stainless | corrosion resistance in those media |
| C86300 / SAE 430B | heavy tillage pivots, disc hubs, shock | hardened | highest strength |
| C95400 | heavy load with water and mud | hardened | seawater and heat resistant |
| CuSn12 | baler guides, oil-lubricated fast oscillation | hardened | wear resistant, lead-free |
Parts we machine for this sector
Typical parts, not customer cases:
- Front axle and three-point linkage bushes Ø25 – 80 mm, C93200, flanged and plain
- Header and reel arm flanged bushes for combines, C93200 / LG2
- Baler plunger guide bushes with grooves, CuSn12
- Disc harrow hub bushes and thrust washers, C86300 / C93200
- Trailer axle and cylinder eye bushes, C93200, metric and inch
What to send for a quote
Old part or drawing – either works:
- Bore (at the unworn end) or pin diameter, outside diameter or housing bore, length; flange if any
- Alloy or the conditions: load, fertiliser / water, greasing habits
- Quantity and whether a sample is wanted first
- Photo of the worn bush or the OEM drawing
Frequently asked questions
Bronze or steel bushing for a harrow pivot?
Bronze – C93200 for normal duty, C86300 for heavy shock. A steel bush on a steel pin galls as soon as the grease is gone, which in tillage is often; bronze embeds the soil and keeps moving, and protects the pin.
Can I get bushings in John Deere or Case sizes?
We machine bushes to the dimensions you measure or the drawing you send, for any make; we do not sell by OEM part number. Give bore, outside diameter and length and we quote.
Do farm machinery bushings need grease?
Cast bronze bushes do – before parking, after washing, and at the interval in the manual. They forgive a missed interval better than steel or plastic but cannot run dry for long.
What is the minimum order?
None. One replacement bush or a season's batch; samples in 3 – 5 days.
Replacement bushings for the season
Send the three dimensions and a photo – no minimum order, samples in 3 – 5 days, quote in 12 hours.