Tank, Vessel & Pressure Equipment Fabrication worked example

Flange Bolt Count at 65% machine uptime: a worked example

This worked example runs the flange bolt count numbers for a tougher week than the baseline: 65% machine uptime instead of the typical 90%. The Flange Bolt Count capacity calculation estimates how many good flange bolt holes a drilling or machining setup can produce over a run, after uptime and first-pass yield losses are taken out.

The inputs for this scenario

  • Bolt holes drilled per cycle: 4 holes / cycle (held at the documented default)
  • Available drilling cycles: 480 cycles (held at the documented default)
  • Machine uptime: 65 % (the input this scenario stresses; the baseline uses 90)
  • First-pass hole yield: 97 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross flange bolt count capacity = units per cycle × available cycles.
  • Good output capacity works out to 1,211 units at these inputs, and this is the headline figure for the scenario.
  • Gross capacity works out to 1,920 units at these inputs.
  • Uptime loss works out to 672 units at these inputs.
  • Yield loss works out to 37.44 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where machine uptime sits at 90% and the headline result is 1,676 units, this scenario comes in 27.78% below the baseline at 1,211 units.
  • Use it when planning a flange-drilling run, sizing capacity against a due date, or diagnosing why good-hole output falls short of the machine's theoretical rate. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Good output capacity: 1,211 units (headline result)
  • Gross capacity: 1,920 units
  • Uptime loss: 672 units
  • Yield loss: 37.44 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Flange Bolt Count calculator, set machine uptime to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.