3 Things Every Engineer Should Know Before Specifying a Sintered Part

You've got a part that's currently machined, cast, or forged — and someone on your team suggested sintering to cut costs. Good instinct. But before you send that drawing to a supplier, here are three things that will determine whether the project succeeds.

1. Know Your Material Standards

Sintered parts use iron-based, copper-based, or stainless steel powders. The achievable properties are solid: 20–25 HRC hardness, densities from 5.8 to 8.3 g/cm³, and tensile strengths up to 225,000 psi (1,550 MPa).

Three material standards dominate the industry:

• MPIF 35 (US) — Format: FC-0205 → 2% Cu, 0.5% C
• DIN 30910 (Germany) — Format: Sint-C11 → 1–5% Cu, 0.4–1.5% C
• JIS Z2550 (Japan) — Format: SMF-4050 → 1–5% Cu, 0.2–1.0% C

If your existing drawings reference any of these, the quoting process goes much faster. If not, a good supplier can help you select the right grade.

2. Design for the Process

Sintering uses vertical compaction molds. That creates specific design constraints:

• Horizontal holes can't be formed in the mold — they require secondary drilling, adding cost
• Minimum wall thickness: 1.5–2 mm for thin sections
• Draft angles: 5–15° on vertical faces to enable clean demolding

Equipment check: Every cm² of cross-section needs 4–7 tons of pressing force. If your supplier doesn't have a press large enough for your part's footprint, they're either outsourcing or overpromising.

3. Run the Cost Math

Sintering molds cost $1,000–$20,000 depending on part size. Daily output can hit 15,000 pieces per mold with excellent dimensional consistency. The key question: does the per-unit mold amortization, combined with the lower per-unit production cost, beat your current process?

For most parts above 5,000 units, the answer is yes. Below that, you need to run the numbers carefully.