Guides / Process

Reverse Engineering a Replacement Part: The Full Process

November 1, 2026

Reverse engineering a part means creating the drawing that should have existed, then making the part from it. Done well, you end up with a replacement that fits and a drawing you can use again.

1. Collect what you have

The worn part is the best starting point. Add anything else you have: photos of where it fits, the machine make and model, catalog pages, partial drawings and a note on what failed. Every piece of context removes guesswork.

2. Measure

Simple features are measured with calipers and micrometers. Bores, positions and flatness on precise parts go on a coordinate measuring machine. Freeform shapes and castings are 3D scanned.

Worn parts need judgment. We measure the unworn areas, check the mating parts and use standard fits where wear has removed the original size. Each of those choices is written on the drawing.

3. Identify the material

Check	What it tells you
Spectrometer	Alloy grade
Hardness test	Whether it was heat treated
Visual and fracture	How it failed

If the original failed by wear or fatigue, this is the moment to choose a better material or treatment.

4. Draw and approve

The result is a 2D drawing with tolerances and a 3D model. You check it before anything is made. Questions at this stage are cheap. Questions after machining are not.

5. Make and inspect

The part is made to the approved drawing and measured against it. You get the part, the inspection report, the drawing and your original sample back.

What to send for an accurate quote

1. Photos of every face with a ruler in the picture
2. The key sizes you can measure yourself
3. Machine make, model and year
4. Quantity now and per year
5. How fast you need it

That is usually enough to give you the route, the price and the lead time before you ship anything.

Frequently asked questions