Yes, you can get a metal part made from a sketch or a photo. What makes it work isn't the drawing quality; it's whether the sketch carries real dimensions, the material and thickness, and a clear idea of which side is which.
Plenty of good parts start on the back of an envelope. A farmer needs a replacement guard, a shopfitter needs twenty brackets that match an old one, a hobbyist has a broken bracket in a plastic bag. None of them have CAD, and they don't need it. What they need is to give the estimator enough to turn the sketch into a cutting file without guessing. Here's what that looks like.
What a usable sketch needs
A sketch doesn't have to be to scale. It does have to be dimensioned. Grab graph paper if you have it, a pencil, and a tape measure or vernier.
Put these on the page:
- Overall sizes. Width, height, and every flange length.
- Every hole. Diameter, plus its position from two edges. "About here" with an arrow costs you a phone call.
- Bends. Draw the bend lines, the angle (90° is the usual), and which way it folds: up or down, towards you or away.
- Material and thickness. "2 mm mild steel" or "1.5 mm aluminium". If it's a copy of an old part and you don't know, say so.
- Quantity. One, ten, or two hundred changes how the job is planned.
- Finish. Raw, painted, or powder coated, and a colour if it matters.
Measure in millimetres. If your tape is in inches, convert before you write it down, not after.
Say which dimensions matter
On almost every part, a few sizes are critical and the rest are "roughly". Circle or star the critical ones: hole centres that must line up with an existing bracket, an inside width that has to slide over a 50 mm tube. This tells whoever draws it up where to be fussy and where a millimetre either way is fine.
How to photograph a part so it can be measured
A photo of an old part is useful, but a photo alone has no scale. A 100 mm bracket and a 300 mm bracket look identical on a phone screen.
Do this instead:
- Lay the part flat on a plain, contrasting background. A sheet of white paper under a dark part works well.
- Put a ruler or tape measure right next to it, in the same plane as the part, not propped up in front.
- Shoot straight down from directly above, not at an angle. Angled shots stretch one end and squash the other.
- Take one shot per face of a bent part, plus one at an angle that shows how the bends relate.
- Write the key dimensions on a printout or a sketch as well. The photo shows shape; the numbers make it buildable.
Worn or damaged parts need a word of warning in the notes. If a hole has been wallowed out to 14 mm but was meant to be 12 mm, tell us. Otherwise we'll copy the damage faithfully.
Sketch, photo, PDF, or CAD: what each gets you
Every format can work. They just leave different amounts of guesswork.
| What you send | Good for | What's usually missing | What to add |
|---|---|---|---|
| Hand sketch | Simple flat or once-bent parts | Exact hole positions, bend direction | Full dimensions, material, thickness |
| Photo of an old part | Copying a worn or broken part | Scale, true sizes, hidden faces | A ruler in shot, key dimensions written down |
| PDF drawing | Most parts, including bent ones | Sometimes the thickness or material | Material, thickness, quantity in the notes |
| DXF or STEP file | Production runs, complex shapes | Often nothing | Quantity and finish |
If you're weighing up whether to learn enough CAD to send a file, our guide to laser cutting file formats explains what each format does well. For a one-off bracket, a clear sketch is honestly fine.
What happens to your sketch at the shop
Someone has to turn your drawing into a clean cutting file before the laser cutting machine can touch it. For a bent part, they also have to work out the flat shape, allowing for how much the metal stretches in each bend. That's estimator time, and the clearer your sketch, the less of it there is.
Expect a question or two back if something is ambiguous. Typical ones we'd ask:
- Is this 40 mm measured to the outside of the bend or the inside?
- Should these two holes line up after folding?
- The old part looks like 3 mm. Is it, or is it 2.5 mm with paint on it?
Answering those before the sheet is cut is far cheaper than discovering them afterwards. If you're ordering something with several pieces that get welded together, a simple sketch of how they fit makes a big difference; our post on fabrication assembly drawings shows what to include without needing CAD.
Inside or outside: the dimension people get wrong
This one deserves its own section because it's the most common sketch error on bent parts.
Say you draw a U-channel as 50 mm wide. Is that across the outside faces, or the gap between the inside faces? On 3 mm steel, the difference is 6 mm. If the channel has to slip over a 50 mm square tube, getting it wrong means it won't fit at all.
Mark it plainly: "50 inside" or "50 outside", or draw the dimension arrows to the face you mean. If a part fits over or into something else, give us the size of that something too. "Must slide over 50 × 50 tube" is the most useful sentence you can write.
Same goes for hole positions on bent parts. Measure from a flat edge or from the outside of a flange, and say which.
Sending it through
Use the normal quote form. It takes DXF, DWG, STEP, PDF, or a photo, up to 10 MB per file, and one-offs go through the same form as production runs. Scanned sketches and phone photos are fine. If your photos are bigger than that, email them to ctrlcutsa@gmail.com.
In the notes, add the quantity, material, thickness, finish, and anything about fit ("replaces a bracket on a 2015 trailer", "must clear a 20 mm pipe"). Not sure what material it should be? Say so, describe where the part lives, and we'll help pick. For more on what makes a quote quick and accurate, see how to get an accurate sheet metal quote.
When you're ready, start a quote for laser cutting and attach your sketch or photos. Bending, welding, and coating can go on the same order.