In daily stamping production, the first thing to lock down is the process sequence—blanking, piercing, forming, flanging, and trimming are the five basic operations that define every die layout. For a typical sheet metal part, the number of stations directly drives tooling cost and cycle time. A simple flat blank with two holes might run on a single-stage die, but a deep-drawn housing with multiple flanges often requires a progressive die with 6 to 12 stations. The rule of thumb we use in quoting is that each additional station adds roughly 8–12% to the die build cost, while the press tonnage must be checked against the sum of cutting force and forming force. Cutting force is calculated as perimeter × thickness × shear strength (for mild steel, about 345 MPa), and we always add a 20–30% safety margin for press selection. Never forget the strip layout—material utilization below 65% means you are throwing money away on scrap, so rotate the part or nest it in two-up layout before finalizing the die design.
On the tooling side, the clearance between punch and die is the most overlooked variable. For 1.0 mm thick SPCC, a typical clearance of 5–8% of material thickness per side gives a clean shear edge, but going too tight causes excessive burr and punch wear, while too loose produces a large rollover and a torn edge. In production, we also watch the stripper force—a spring-loaded stripper should provide at least 15–20% of the cutting force to keep the strip flat and prevent distortion. For high-volume runs, use carbide inserts on the piercing punches and die buttons; they cost about 2.5× more than tool steel but last 4–6 times longer, which pays off above 100,000 strokes. Also, check the die shut height and press stroke—a common mistake is using a press with too short a stroke for deep drawing, causing the punch to hit the die plate. Always set the die tryout with a 0.05 mm shim under the stripper to verify the clearance before production.
When quoting a stamping job, break down the cost into four blocks: material, tooling amortization, press time, and secondary operations. Material cost is simply blank weight × coil price per kg, but do not forget the scrap credit—selling the skeleton and offal can recover 10–15% of material cost. Press time is the cycle rate (strokes per minute) divided by the number of hits per part, plus a 5% allowance for loading and unloading. Secondary operations like deburring, tapping, or welding often add 20–30% to the total part cost, so try to design them out. For a realistic quote, always run a quick simulation of the strip layout and estimate the die life—a progressive die for 0.8 mm galvanized steel should hit 500,000 strokes before major maintenance. If you need a reliable mold partner or want to compare stamping die quotes from verified suppliers, visit MoldWorld at www.moldw.com for more mold sourcing information.