DEMO — fictional range. Local brief only, NOT SENT. No personal data is collected or transmitted.
GUIDE
The order the questions are worth asking in.
This is the sequence a programme for a part bought in quantity follows when it goes well, and the point at which each step becomes expensive to revisit.
- 1 · The assembly
- What it threads onto or seats against
- 2 · The thread class
- Not the nominal size, and not left to the shop
- 3 · Material
- Chosen for the load, then for how it machines at speed
- 4 · Finish
- And whether the thread is gauged before or after it
- 5 · Tolerance
- Set from the first four, not copied from an earlier drawing
- 6 · The run
- One batch or several, and how far apart
- 7 · Sampling
- What is measured, how many, and against what gauge
- 8 · The batch record
- First and last piece, tool changes, and what was rejected
Why the order matters.
Each step constrains the next. Choosing a thread class before the finish is choosing a fit for a coating that has not been decided, and choosing a sampling plan before the run length is choosing how much you will not know.
Where programmes usually go wrong.
Step two, left to the shop, and step six, assumed to be a single batch. Both are cheap to settle and expensive to discover.