What to Send When a Replacement Part Has No Current Drawing

A machine built twenty years ago may have no drawing anywhere, and the part still needs replacing. Nothing about that stops a fabrication review, provided the information sent describes the part accurately.

What actually starts a review

KorFab can fabricate from drawings, written specifications, sketches, photos with dimensions, or a physical sample. What it cannot do is measure the part in the field, reverse engineer a component or take responsibility for the design of a replacement. Those are outside what the shop offers, so the information has to come from the plant or its engineering support.

The most useful single document is a dimensioned sketch of the existing part, even a rough one, with every dimension that matters written down.

Build the record

• Outline dimensions, overall length, width and thickness.
• Hole positions, referenced to two edges rather than laid out roughly, with size and thread if any.
• Material, if it is known, or the best available identification: magnetic or not, appearance, whether it was coated, what it mates with.
• Thickness measured where it matters, not guessed from the outside.
• Any feature that the function depends on: a step, a shoulder, a slot, a machined face.
• Photos, with a rule or a known object in frame for scale.

Say what it has to do

A measured part reproduces a shape. Knowing what the part does explains why a dimension is what it is, which matters where the original has worn. A bore that has opened up from wear measures larger than it was made, and copying the worn dimension produces a part that does not fit.

So state the function: what it attaches to, what moves against it, and whether a worn dimension is suspected.

Boundaries to settle early

• Who confirms the dimensions. The shop quotes from what it is given.
• Whether an acceptable deviation exists, and who accepts it.
• Whether a replacement is allowed to differ from the original in material or thickness.
• Who fits it.

Then the usual information

Quantity, finish, the date needed and delivery destination. With those four plus a usable record, a quote is possible. Without the record, the honest answer is that the shop needs it before it can price the work.

Ordering replacement components before planned maintenance covers the scheduling side of this same situation.