How to Choose Commercial Vehicle Brake Housings & Hubs (ADI Guide)

Table of contents

Where these parts live and what they see

Brake housings and hubs handle clamp loads, bolt preload, thermal cycles from braking, road-salt corrosion, and high-cycle bending from wheel loads. Typical risks are thermal cracking, fatigue at bolt circles, NVH complaints, and corrosion at interfaces. Getting material × process × geometry right up front avoids rework later.

Material options at a glance

Typical properties shown are indicative windows for design screening (room temperature). Final values depend on section size, process, and heat treatment.

Process window (ADI, indicative): austenitize roughly 840–900 °C, austemper roughly 250–400 °C depending on grade and target properties.

When to choose gray iron, ductile iron or ADI

Pick Gray Iron when…

• Brake NVH (noise/vibration) is critical—gray iron’s graphite flakes give high damping.
• The design has thick sections and you want predictable machinability & cost.
• Surface finish after machining must be fine on sealing or friction faces.

Pick Ductile Iron when…

• You need higher tensile & fatigue than gray at similar wall thickness.
• You have impact risks (potholes, off-road) and want more toughness.
• You want bolted hub areas to keep preload under high cycles.

Pick ADI when…

• There’s a weight reduction target or a need to shrink wall thickness.
• You need fatigue strength uplift without switching to cast steel.
• Your volume justifies controlled heat treatment and the NVH trade-off is acceptable.

Design rules that save weight and cost

• Wall thickness & uniformity: avoid sudden jumps; keep ribs to ≤ 60–70% of adjacent wall; blend with generous radii. See Wall Thickness Rules
• Radii & transitions: use fillets at bolt circles and spoke roots to kill stress concentrations. See Fillets & Radii .
• Bolt circles: add under-head pads and compressive fillets; keep edge distance to threads.
• Cooling features (drums): use consistent mass around the friction band; avoid isolated hot spots.
• Draft & stock: set machining allowance only where needed; heavy stock on large faces drives cycle time.
• Corrosion interfaces: specify coatings or conversion layers at hub-to-disc interfaces if galvanic pairs exist.

Casting processes & tolerances that fit CV parts

• Green sand for mainstream housings/drums; best cost at medium–high volume. Capability & cost curve.
• Resin sand, where geometry is complex or you need cleaner surfaces; compare with green sand .
• Shell molding for thinner-wall hubs or precision cores when volumes justify tooling.

As-cast tolerance target: call out ISO 8062 CT by size band (e.g., CT8–CT10 typical for these sizes).

Machining, surface & balancing notes

• Datum strategy: set robust cast datums away from heavy flash/parting; plan one-and-done fixturing for bores + faces. Fixturing ideas.
• Surface finish: sealing faces often target Ra 1.6–3.2 µm; external cosmetic faces can be as-cast with shot-blast.
• Balancing: for rotating hubs/drums, agree on a balance grade and correction method (spot drill vs weights).
• Coatings: powder or epoxy for cosmetics/corrosion; mask critical bores and seats.
• Cutting data: gray iron machines fastest; ADI needs tougher tooling and stable fixtures—plan cycle time accordingly. Tooling notes → /tooling-for-cast-iron.

Quality plan & acceptance checks

• PPAP/FAI as required (PPAP level, FMEA, Control Plan, full dimensional on 5 pcs). Guide.
• Metallurgy: spectrometer per heat; hardness trend; microstructure snapshots (ADI: ausferrite verification).
• Dimensional: CMM or 3D scan of bolt circles, bores, runout, overall envelope.
• Functional: pressure or leak tests if housings carry fluid; torque proof on studs/inserts.
• Coating: DFT checks and adhesion; masked areas verified clean.
• KPI targets: align PPM/DPPM/OTD before SOP. Reference.

What YBmetal delivers

YB Metal Solution produces brake housings, hubs, and related CV castings in gray/grey, ductil,e and ADI with:

• Processes: green/resin sand + shell cores; simulation-backed gating; prototype to mass production.
• Heat treatment: controlled ADI cycles with batch records.
• Inspection: OES, tensile/hardness, microstructure, CMM & 3D scan, dynamic balance checks.
• Documentation: APQP/PPAP up to Level 3, full traceability.

Upload your drawing and YBmetal will reply with a material/process choice, weight-saving ideas, and a quote.