Marking Metal Parts Before Drilling or Bending: A Pencil Workflow
By eitech Metallbaukasten | Published: 2026-10-31
Category: How-to Guides
Learn how to mark drill points and bend lines on eitech metal parts with a yellow plastic pencil, including layout, checking, and re-marking steps.
Quick answer
Use a yellow plastic pencil to mark each drill point and bend line directly on the metal, then check the marks against your plan before you drill or bend. Make light marks first, confirm the position, and only then commit to a deeper mark or center punch.
Why a pencil beats a permanent marker for layout
A pencil line sits on the surface without flooding the area, so you can still see the edge of a flat bar or the center of a hole. Permanent marker can smear when you handle oily metal and may need solvent to remove, which is a problem on plated or painted eitech parts.
The trade-off is that pencil lines are faint and can rub off during handling. That is why the steps below include a check pass and a re-mark before any drilling.
When to skip the pencil and use a center punch
For a drill point that must be exact, such as a hole that aligns with an existing socket or flat bar, a pencil mark alone can let the bit wander. After marking with the pencil, add a light center-punch dimple at the intersection. The pencil stays useful for labeling the part and marking bend lines, but the punch takes over for the drill point itself.
Step-by-step marking workflow
- Clean and dry the part: Wipe the metal with a dry cloth to remove oil and dust before you mark. Pencil graphite does not bond well to a slick or dirty surface. If the cloth picks up grease, clean again; a mark on oil will smear and mislead you.
- Lay out reference lines first: Use a ruler or the mating part to draw a light baseline along the edge or centerline. Mark from that baseline rather than guessing each hole position separately. Check that the baseline follows the actual edge, not a bent or burred corner.
- Mark drill points with a small cross: Draw a short cross at each hole center instead of a filled dot. The intersection of the cross is easier to align with a drill bit or center punch. Keep the cross small; a large mark hides the true center.
- Mark bend lines on the visible side: Draw the bend line on the side that will stay visible after bending, and add an arrow showing the bend direction. This prevents bending the part the wrong way. If the bend line will be hidden, add a small label on the back side too.
- Check marks against the plan before drilling: Hold the part next to its mating part or lay it on the plan. Confirm hole spacing and bend direction before any metal is removed. A pencil mark is easy to erase now and impossible to undo after drilling.
- Re-mark any faint lines: Go over lines that faded during handling with the same pencil. Do not switch to a marker at this stage; a fresh pencil line keeps the layout consistent. If a line keeps rubbing off, the surface is still oily; clean it again before re-marking.
Product facts
- Pencil, yellow (plastic): Yellow plastic pencil, SKU 01613 GELB, under the eitech brand. The yellow color stands out on bare metal and dark plated parts, so your layout marks are easier to see while you work.
Pencil, yellow (plastic)
