20 Million Thin Steel Diaphragm Discs for Disposable Medical Pumps

An IV-set maker runs a flow-through valve with a pulsating pump. Inside sits a stamped steel disc that rides against the pump; because the whole valve is thrown away at every fluid change, the part is cheap but cannot be sloppy. The drawing asked to thin a 1.0 mm blank down to a 0.5 mm outer ring while keeping a raised 12.7 mm inner circle — and to stay flat enough that the tin plating wouldn't distort it.

Thinning by grinding was out at this price point. We thinned in the die: the press pushes the inner circle below the strip line for a half-cut on the outer diameter, then coins a 0.5 mm ring from the die side before flat-forming. The plating step got one change too — protective media in the barrel stops the finished discs sticking face-to-face.

Outcome

• Sustained volume above 20,000,000 discs per year
• Flatness held at 0.01 mm after plating; no discoloration rejects on the last 24 releases
• Runs on a high-speed progressive press in the 30–45 T band, CRS 1008 stock
• PPAP-level dimensional reports per shipment; CMM sampling on a Zeiss CONTURA (0.001 mm)

Specifications

material CRS 1008 · 1.0 mm parent / 0.5 mm coined ring · MIL-spec-equivalent electro-tin 2.5–5.0 µm · MOQ 10,000