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Getting Started

  1. Open the app and tap Input in the bottom navigation bar.
  2. Select a fastener type at the top: Bolt, Washer, or Nut.
  3. Pick a Metric size from the dropdown. The dimension fields fill in automatically - Except for some field!.
  4. Adjust any dimension if your fastener differs from the ISO standard.
  5. Tap the + button in the bottom-right corner to add it to the list.

Tap List in the bottom navigation bar. You’ll see:

  • Each fastener with its size, type, and calculated surface area.
  • A summary bar at the bottom showing total surface area and amps needed.

Repeat the process for each fastener in your batch. Mix and match bolts, washers, and nuts — the app totals all of them together.