Strip Yield

Improving Strip Layout Yield in Progressive Dies

In a progressive die the strip layout fixes material cost for the life of the tool. Here is the yield math, the benchmark ranges, and the design and floor levers that recover points.

A progressive die freezes its material cost the day the strip layout is approved, and it keeps charging that price for 5 to 10 years. Yield equals part area divided by pitch times strip width. Worked example: a bracket with 2,150 square millimeters of part area on a 62 mm pitch and 55 mm wide strip consumes 3,410 square millimeters per part, a 63.1 percent yield. Run 2 million parts a year in 1.5 mm steel at $950 per ton and the strip consumes about 80 tons; each yield point recovered is worth roughly $1,200 per die per year, and most captive shops run 30 to 60 progressive dies.

Measure engineered and actual separately. Engineered yield comes off the strip drawing. Actual yield equals good part weight shipped divided by coil weight consumed, and it always runs lower because of coil ends, threading scrap, setup hits, and rejects. Worked check: the 40 gram part above at 63.1 percent engineered should consume 63.4 grams of strip; if coil receipts show 68 grams per good part, actual yield is 58.8 and the 4.3 point gap is execution loss. The Strip Layout Yield calculator turns pitch, width, and part area into the engineered number in seconds; weigh scrap hoppers weekly to get the actual one.

Benchmark ranges by part class. Simple flat washers and links in single out layouts run 65 to 80 percent. Typical brackets with one carrier land 55 to 70. Parts with big cutouts, deep forms, or double carriers sink to 40 to 55. Two out and four out layouts usually add 3 to 8 points over single out on the same part because carriers and end scrap amortize across more pieces. If a new layout comes in more than 5 points under the class range, send it back with questions before a single die section is machined, because after tryout the answer is always no.

The design levers: shrink pitch and web to the safe minimum, typically web width of 1.5 times material thickness or 1.5 mm, whichever is larger, and carrier width of 2 to 3 times thickness. Cutting pitch from 62 to 59 mm on the example part lifts yield 4.8 percent by itself. Rotate or mirror the part; a 15 degree rotation sometimes drops strip width 6 to 8 percent. Move from double carrier to single side or center carrier where strip stability allows. And question every pilot hole punched in fresh material when an existing part feature could pilot the strip instead.

Multi out layouts deserve their own math. A two out die costs 40 to 60 percent more to build but doubles parts per stroke and typically adds 3 to 8 yield points. On a 3 million part annual volume, if two out saves 5 points on an 80 ton material bill and halves press hours at $250 per hour, the extra $45,000 in tooling often pays back inside 12 to 18 months. Run the same analysis on width: two parts nested head to head across the strip can beat two out along the strip. Layout reviews should always price at least three alternatives.

Floor execution protects the engineered number. Hold coil width tolerance; ordering strip at plus or minus 0.5 mm instead of plus or minus 1.5 lets you cut the design margin 2 mm on a 55 mm strip, nearly 4 points. Keep coil end loss under 3 meters per end with a stagger sequence or joining welds. Standardize setups so first piece approval takes 15 hits, not 60. Track scrapped strip per coil change: at 8 changes a day and 5 meters saved per change, a 55 mm by 1.5 mm steel strip saves about 26 kilograms daily, over 6 tons a year on one line.

Failure modes worth scars. Shaving web below 1.5 times thickness cracks die sections and causes strip wander misfeeds, and one crash can cost $15,000 to $40,000 in die repair plus a week of delivery pain, wiping out years of the 2 percent material saving that caused it. Yield reported on part count instead of weight hides trim changes. Nobody recalculates yield after an engineering change adds a hole, so the standard drifts optimistic. And purchasing substituting a wider stock coil to save $15 a ton can burn $40 a ton in yield; the two spreadsheets never meet unless you force them into one review.

Cadence and the finish line. Daily: coil consumed versus parts produced on the top five dies, flag anything 2 points under standard. Weekly: scrap weight Pareto by die, one corrective action with an owner. At every new die kickoff: a strip layout review that scores at least three options for yield, die cost, and SPM, signed by tooling, quality, and purchasing. World class means actual within 1.5 points of engineered plant wide, engineered yield in the top third of the class range for every new tool, and a die room that treats a 1 point yield idea with the same respect as a 1 SPM speed idea, because over a tool's life it is usually worth more.

Published 2026-07-02.