3 Critical Factors for Sintering Part Design

When companies look to reduce manufacturing costs, sintering is often the answer. But transitioning a part from machining, casting, or forging to sintering isn't as simple as sending a drawing to a factory. There are three critical factors that determine whether your sintered part will meet spec — and budget.

1. Material Selection: Getting the Foundation Right

Sintered parts typically use iron-based, copper-based, or stainless steel-based powders. The material you choose directly affects the part's hardness, density, and tensile strength. Here's what's achievable:

• Macro hardness: 20–25 HRC
• Density range: 5.8–8.3 g/cm³
• Maximum tensile strength: 225,000 psi (1,550 MPa)

Three international standards govern sintered materials: MPIF 35 (US), DIN 30910 (Germany), and JIS Z2550 (Japan). If your existing drawings reference any of these codes, the quoting process becomes significantly faster.

2. Structural Design: Designing for the Process

Sintering uses molds with a vertical compacting direction. This means certain geometries need special attention:

• Horizontal holes require post-machining drilling — adding cost and reducing efficiency.
• Wall thickness must exceed 1.5–2 mm for thin-wall sections.
• Draft angles of 5–15° on vertical faces help with demolding and eliminate secondary machining.

A useful rule of thumb for equipment sizing: every square centimeter of part cross-section requires 4–7 tons of pressing force. If a supplier claims they can make your part but doesn't have the right tonnage press — that's a red flag.

3. Cost-Effectiveness: Running the Numbers

Mold investment for sintering typically ranges from $1,000 to $20,000, depending on part size and complexity. The upside? Sintering can deliver up to 15,000 pieces per day per mold with exceptional dimensional consistency.

The key calculation: divide the mold cost across your expected order volume. If the per-unit mold amortization makes the total cost competitive with your current process (machining, casting, forging, or stamping), sintering is likely the right move.