Deep drawing
How do I calculate the blank size for a deep drawn cup?
Answer
How To Calculate Blank Size For A Deep Drawn Cup? Blank size for a deep drawn cup: the classical D = sqrt(d2 + 4dh) formula, the accurate surface-area method, a worked 50 mm example and the trim allowance. The blank diameter is the first number that decides whether a deep drawn cup is cheap or expensive, because it sets how much sheet metal goes into the press and how much of it ends up on the floor as trimmed rim. It is also the number most often copied from a similar part instead of calculated.
Sources
- How To Calculate Blank Size For A Deep Drawn Cup?How To Calculate Blank Size For A Deep Drawn Cup? Blank size for a deep drawn cup: the classical D = sqrt(d2 + 4dh) formula, the accurate surface-area method, a worked 50 mm example and the trim allowance. The blank diameter is the first number that decides whether a deep drawn cup is cheap or expen...
- How To Calculate Blank Size For A Deep Drawn Cup?Home › Blog › Deep Draw Metal Stamping Deep Drawing · Blank Development · DC04 & 304 How To Calculate Blank Size For A Deep Drawn Cup? Published September 26, 2026 · Balford Technical Team The blank diameter is the first number that decides whether a deep drawn cup is cheap or expen...
- Deep Drawing Calculation: A Worked Example | BalfordDeep drawing calculation: a worked example A 40 mm diameter, 30 mm deep cup in 1.0 mm DC04 — the blank, the draw ratio, the draw force, the press and the die clearance, all the way through, with every assumption written down so you can check it. What this is for. The point is not the numbers for thi...
- Drawn Sheet Metal & Deep Drawing: Complete Guide | BalfordTry it: deep draw force calculator — put in the blank diameter, the punch diameter, the sheet thickness and the tensile strength, and it returns the draw force, the draw ratio and a press tonnage you can quote against. Terminology: deep drawing terminology — drawing vs deep drawing, redrawing,...
- What Is Deep Drawing? A Clear Definition | BalfordWorked example: deep drawing calculation, step by step — a 40 mm × 30 mm cup worked all the way through: blank diameter, draw ratio, draw force, press and die clearance, with every assumption written down....
- How Many Draws Does A Deep Drawn Part Need?Take a 40 mm outside diameter, 30 mm high cup in 1.0 mm DC04. The blank works out at 80 mm, so the overall ratio is 2.0. That is right at the edge of the DC04 first-draw limit, so the part is planned as two draws rather than gambling on a single operation. Stage Diameter Ratio for that stage Within ...
What an engineer still needs from you
- material and material condition (grade, temper)
- material thickness, plus the key diameter, height and wall thickness
- tolerances, burr direction and the visual acceptance standard
- annual volume - it decides whether tooling is single-hit, progressive or transfer
- surface finish, and any secondary machining, annealing or plating
Need a DFM feasibility assessment for your project?
Send the engineering drawing (STEP or PDF) with the material grade, thickness and annual volume. Balford engineers then check it against the process window - draw ratio, wall thickness, tolerances, blank and tooling route - and come back with what is feasible and what is not. An answer on this page cannot replace that review.
Upload a drawing for DFM reviewHow the DFM review worksRelated questions
- What is deep drawing?
- Deep drawing vs progressive die stamping: which process fits my part?
- What is the maximum deep draw diameter and press capacity?
- What draw ratio is possible in one deep drawing stage?
- How can I reduce cracking when deep drawing stainless steel?
- What are the common deep drawing defects and their causes?
This page is an engineering answer, not a quotation and not a dimensional acceptance. It is generated from Balford's published material and held to the verified company fact sheet.