Quick Answer
Farm equipment castings live a brutal life: soil abrasion, rock impact, shock torque, weather — and price pressure on top. The material split that works: ductile iron (A536 65-45-12 / 80-55-06) for housings, hubs, brackets and rollers; quench-and-tempered cast steel or high-hardness irons for ground-engaging and wear parts; gray iron for counterweights and non-critical brackets. The economics are unforgiving, which is exactly why getting grade and process right per part — instead of one habit grade everywhere — is where sourcing money is made.
Part Families and Their Materials
| Part family | Typical choice | Reasoning |
|---|---|---|
| Gearbox housings, PTO parts | Ductile iron 65-45-12 | Toughness for shock torque; machinability |
| Wheel hubs, rollers, idlers | Ductile iron 65-45-12 / 80-55-06 | Fatigue plus impact from rough ground |
| Tillage points, shares, teeth | Q&T cast steel or boron steel; sometimes chilled iron | Abrasion; sacrificial wear economics |
| Brackets, links, levers | Ductile iron; cast steel when welded to frames | Iron cannot be structurally welded — steel can |
| Counterweights | Gray iron Class 20–30 | Mass at minimum cost |
| Pump/sprayer wet ends | CF8M stainless | Fertilizer and chemical corrosion |
The Three Design Realities of Ag Service
- Impact beats static strength. A rock strike loads parts in milliseconds — elongation and impact toughness (ductile iron’s 12–18%, steel’s Charpy values) matter more than tensile numbers. This is why gray iron, superb elsewhere, is banned from load paths; the family logic is in our A536 grade guide.
- Abrasion is a consumable budget. Ground-engaging parts are designed to wear and be replaced — the casting question is wear-life per dollar, solved with Q&T hardness (see quenching and tempering), hardfacing on parent castings, or deliberately cheap sacrificial iron.
- Weld-repair culture. Farmers weld. Parts that bolt to welded frames should be cast steel, not iron, so field repairs hold — a detail that separates ag-experienced foundries from generalists.
Sourcing Notes for OEM Buyers
- Seasonality: order cycles compress before planting/harvest seasons — book foundry capacity against your season, not your fiscal calendar
- Paint-ready surfaces: shot blast class and priming agreed up front; field equipment sells partly on finish
- Interchangeability with legacy parts: datum documents matter more than nominal drawings for 20-year-old equipment lines
- Cost engineering: pattern consolidation (families of sizes on shared plates) and machining-allowance discipline typically release 10–15% cost in mature ag lines
YCUMETAL supplies ag-machinery castings — hubs, housings, brackets, rollers and wear parts — in ductile iron, gray iron and steel with sand casting plus in-house machining; agricultural machinery is one of the industries listed in our factory profile.
FAQ
Ductile iron or cast steel for a shock-loaded bracket?
Ductile iron 65-45-12 if it bolts on; cast steel if it welds on or sees extreme cold (iron toughness drops below −20°C faster than LCB-class steel).
What hardness should tillage wear parts have?
Commonly 45–55 HRC via Q&T or boron steel — balanced against brittleness from rock impact. Field conditions decide; specify by soil type experience, not by maximum number.
Are castings or fabrications cheaper for ag brackets?
Below ~50 pieces, fabrication usually wins; above, casting amortizes tooling and removes weld labor. Run the crossover per part, not per catalog.