Fastening, Torque & Joint Assembly worked example

Fastener Cost Per Unit at 118% usage, scrap, or overage factor: a worked example

What does the result look like when usage, scrap, or overage factor reaches 118%? The full calculation is worked below with real intermediate numbers. Use it when comparing screws, bolts, nuts, washers, rivets, inserts, or special coated fasteners in an assembly cost model.

The inputs for this scenario

  • Fasteners used in assembly scope: 36 pieces (unchanged)
  • Purchased fastener price: 0.18 $ / piece (unchanged)
  • Usage, scrap, or overage factor: 118 % (raised for this scenario; the documented default is 103)
  • Fixed sourcing or handling cost: 12 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Variable fastener cost = fasteners used × purchased fastener price × usage factor) to the inputs above produces each figure below.
  • At this operating point the engine returns 19.68 $ for total fastener cost for scope, the number this scenario is built around.
  • At this operating point the engine returns 0.55 $ / piece for average cost per entered fastener.
  • At this operating point the engine returns 7.68 $ for variable purchased fastener cost.
  • At this operating point the engine returns 12 $ for fixed sourcing/handling cost.

How this compares with the baseline

  • Against the tool's baseline example, where usage, scrap, or overage factor sits at 103% and the headline result is 18.67 $, this scenario comes in 5.36% above the baseline at 19.68 $.
  • A figure at this level is achievable when usage, scrap, or overage factor is genuinely sustained, not just peaked for a shift. It uses a single average price and one usage factor, so a mixed bag of fastener types or sizes needs to be costed separately or blended carefully into the inputs.

Results at a glance

  • Total fastener cost for scope: 19.68 $ (headline result)
  • Average cost per entered fastener: 0.55 $ / piece
  • Variable purchased fastener cost: 7.68 $
  • Fixed sourcing/handling cost: 12 $

Run it with your numbers

  • Every input above is editable in the live Fastener Cost Per Unit calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.