Material Utilization and Cost

Predict first: can the same 1,000 mm stock still supply ten 98 mm blanks if separating kerf increases from 2 to 3 mm? What happens to stock cost per blank when the stock price stays $48?

This one-dimensional lab reserves a full separating kerf after every blank, including the last. Left and right excluded trim lengths already include their own cut losses. The layout does not use the far stock edge as a finished blank edge; it is a count under this policy, not a claim of globally maximum yield.

Usable interval U = stock length L − left excluded trim − right excluded trim
Blank count n = floor[U / (blank length b + separating kerf k)]. Round down to a whole number. There are n separating cuts, plus any preparation already accounted for in excluded trim.

Each outlined block is an actual 98 mm blank; the narrow filled band after each is its full 2 mm kerf. Ten blanks plus ten kerfs fill this stock exactly. On narrow screens, scroll sideways to inspect the full bar.

Material balance: 1,000 mm = 0 excluded trim + 980 acceptable blanks + 20 separating kerfs + 0 offcut. Utilization = 980 / 1,000 × 100 = 98.0%.

Change the kerf to 3 mm: ten blanks would need 10 × (98 + 3) = 1,010 mm, so only nine fit. The new balance is 1,000 = 0 + 882 + 27 + 91 mm. The 91 mm offcut is 10 mm short of another 101 mm blank-and-kerf interval.

Allocate the whole stock charge: $48 / 10 = $4.80 per acceptable blank in the original layout; $48 / 9 ≈ $5.33 after the kerf change. All equal-cross-section blanks are assumed acceptable. No remnant credit or processing cost is included. If zero blanks fit, cost per blank is undefined.

Another threshold: at 2 mm kerf, 999.99 mm stock fits nine blanks, while 1,000.00 mm fits ten. This lab uses hundredths of a millimeter and currency cents; its bounded illustrative values are not machine settings. It is not a two-dimensional nesting tool.