Specifications
| Parameter | Specification |
|---|---|
| Material | Low-alloy steel AISI 4140 (QT); carbon steel AISI 1045 or ASTM A216 WCB on request |
| Process | Silica sol lost wax investment casting, CNC milling and drilling, deburring |
| Tolerance | As-cast ISO 8062 CT6; machined features to ISO 2768-m, critical bores and hole patterns +/- 0.05 mm |
| Surface finish | As-cast Ra 6.3 um after shot blast Sa 2.5; machined seating faces Ra 1.6-3.2 um |
| Weight range | 0.6 – 2.4 kg per piece |
| Heat treatment | Austenitize, oil quench and temper to 28-34 HRC (269-321 HBW per ISO 6506); normalize option for 1045 |
| Inspection | CMM dimensional report, magnetic particle inspection per ISO 9934, hardness mapping, gauge fit check |
Key features
- One-piece near-net-shape casting replaces three-part weldments, removing the heat affected zone that cracks at the blade root under shock loading.
- Controlled root fillet radii of R4-R8 are cast in, not machined, so the grain flow follows the load path from blade seat to mounting flange.
- Quenched and tempered AISI 4140 delivers 900-1050 MPa tensile with 12 percent minimum elongation, absorbing stone-strike impact without brittle fracture.
- Bolt hole patterns machined in a single CNC setup guarantee true position within 0.08 mm, so brackets interchange on the rotor without reaming during field service.
- Moreover, Hardened and ground blade seating face resists fretting and keeps bolt preload stable across 500 plus hours of vibration.
- Wall thickness taper from 8 mm at the flange to 5 mm at the blade ear reduces rotating mass by 15 percent versus a plate-steel bracket, cutting rotor drive torque.
- Generally, Corrosion protection options include manganese phosphate, zinc phosphate plus powder coat, or hot-dip galvanizing for paddy and wet-soil service.
Applications
- Rotary tillers and power tillers for paddy, orchard and vineyard soil preparation
- Secondary tillage rotary cultivators on 40-120 hp tractors
- Stone-burier and seedbed preparation rotors
- Rotary hoe and strip-till units
- Compact tractor and two-wheel tractor rotary attachments
- Aftermarket service kits and replacement blade holder sets
Quality & compliance
Every rotary tiller blade holder bracket is produced under an IATF 16949 certified process control system: approved foundry practice cards, controlled melt practice with spectrometer-verified chemistry, and documented heat treatment charts from calibrated furnaces. PPAP discipline (Level 1 through Level 4) is applied where requested, including process flow, control plan, PFMEA and capability studies on critical dimensions. Material certification is issued to EN and ASTM grades, with full chemical and mechanical test reports, and every production lot carries heat lot traceability from melt to finished part. Dimensional reporting is issued per part or per lot, and coating options include phosphate, powder coat, e-coat and galvanizing with documented salt spray results.
FAQ
Q1. Which material do you recommend for a rotary tiller blade holder used in stony soil?
AISI 4140 quenched and tempered to 28-34 HRC is our standard recommendation for stony or compacted ground because the tempered martensite structure combines high yield strength with impact toughness. Where the design is stiffness governed rather than impact governed, AISI 1045 normalized or ASTM A216 WCB offers a lower cost alternative with adequate service life.
Q2. Can you cast the bracket from our existing welded assembly drawing?
Yes. Send the current weldment drawing, a sample part, or a 3D model and our engineering team will redesign it as a single near-net-shape casting. We typically consolidate fasteners, add casting fillets and draft to suit the lost wax process, and return a manufacturing proposal with tooling cost, piece price and a sample lead time.
Q3. What tolerances can you hold on the blade mounting holes?
As-cast geometry meets ISO 8062 CT6, which is normally sufficient for the non-critical outer form. Bolt holes, the blade seating face and the pilot diameter are CNC machined to ISO 2768-m with true position within 0.08 mm, and we verify them on a CMM against your drawing datums.
Q4. Do you supply heat treatment records and hardness data?
Each batch ships with a heat treatment chart showing furnace load, soak temperature, quench medium and temper cycle, plus hardness readings taken per ISO 6506 on a defined sampling plan. Moreover, tensile and Charpy results are available for qualification lots.
Machining scope
Q5. What is the typical tooling and sampling lead time?
Investment casting tooling for a bracket of this size is typically completed in 25-35 days, with first article samples following 10-15 days later. Machining fixtures are designed in parallel, so pilot production can start immediately after sample approval.
Q6. How do we request a quotation?
Email your drawing (STEP, DWG or PDF), quantities and target annual volume to Wendy She at sales@cnsandcasting.com, or message WhatsApp +86-13777124360. Also, you will receive a price breakdown covering tooling, sample pieces and production pricing, normally within two working days.
