How to Prepare Drawings for a Fabrication Quote

Guide

The single biggest cause of delay in a fabrication quote is an incomplete drawing. A fabricator cannot price what they cannot read, so an unclear file comes back as a list of questions rather than a number. Getting the drawing right the first time usually saves a week.

Send the right file format

For flat parts that will be cut, send a DXF or DWG. These are vector files, so the cutting machine reads the geometry directly. A PDF can be quoted from, but it has to be redrawn first, which costs time and introduces the risk of a transcription error.

For anything three-dimensional — a frame, a bracket assembly, a bent part — send a STEP or IGES file alongside a dimensioned PDF. The 3D model shows intent; the PDF shows what actually matters.

Clean up the geometry before you send it

• Close every contour. Open polylines and tiny gaps at line ends make the cutting path ambiguous. Most CAD packages have a join or heal command.
• Remove duplicate lines. Two lines stacked on the same path mean the machine cuts twice, which wastes time and can spoil the edge.
• Delete construction layers. Dimensions, hatching, title blocks and centrelines all read as cut geometry. Send only the profile.
• Convert text to outlines if lettering is meant to be cut. Live text depends on a font the fabricator may not have.
• Work at 1:1 in millimetres. Scaled drawings are the most common source of parts arriving the wrong size.

State the material, not just the thickness

"3 mm steel" is not a specification. Mild steel, stainless 304 and stainless 316 behave differently, cost differently and are cut differently. Give the grade, the thickness and, where it matters, the surface finish. If a part will be exposed to weather or wash-down, say so — it changes the recommendation.

Call out tolerances only where you need them

Blanket-tightening every dimension raises the price for no benefit. Identify the two or three features that must be held — a bolt hole pitch, a mating face, an overall length that fits an existing opening — and let the rest run at standard shop tolerance.

Say what happens after cutting

A quote for cutting alone is very different from a quote for a finished part. Note whether you need deburring, bending, tapping, welding, powder coating or galvanising, and whether the part needs to be delivered assembled. Bends in particular need to be declared early, because bend allowance affects the flat pattern.

The details people forget

• Quantity — the price per part changes dramatically between one and fifty.
• Grain direction on brushed stainless, if the finish is visible.
• Which face is outward on parts that are not symmetrical.
• Delivery date and whether it is fixed or flexible.
• Site access, if the piece is large enough that getting it in is part of the job.

A short checklist

Before sending: file is DXF or STEP, contours closed, duplicates removed, scale 1:1 in millimetres, material grade and thickness stated, critical tolerances marked, finishing and assembly described, quantity and date given.

Send drawings to our team and we will come back with a price rather than a question. See what we can cut and form on our laser cutting, bending and CNC machining pages.