Blog · Drawings · 29 Sep 2026 · 2 min read

Can AI dimension bevels on cutting drawings? Only if it writes the side

An AI agent can place bevel dimensions on hundreds of drawings. But a bevel angle without its side is half an instruction. Where to show the bevel, how to write it, and the sign that tells the cutter which face to cut.

A plate with a bevel has two faces, and the bevel is cut from one of them. A drawing that says 25° tells the cutter the angle. It does not tell them which face. Half the time, they will guess right.

An AI agent placing bevel dimensions in batch has the same problem, multiplied: if nobody tells it how to write the side, it will write the angle alone on every drawing. These are the rules we give it.

Show the bevel where the cut edge is visible

Draw the bevel in the view where the inclined edge is seen as a line, usually one of the thin side views, or in a detail view enlarged around the edge. In the flat cutting view the bevel is often only a hidden line, and a dimension attached to a hidden line is easy to misread.

Write the angle with its size

A common form is depth x angle, for example 8x25°: a bevel 8 mm deep at 25 degrees. Written this way, the dimension carries everything needed to set up the cut, not just the angle.

Give the angle a sign

The face is the part that gets lost. We read it from the cutting view, the view the machine works from:

• the bevel's inner edge drawn as a continuous line means the bevel is on the visible face: +
• drawn as a dashed line, it is on the hidden face: -

The sign goes on the angle: 8x+25° or 8x-25°. Anyone reading the drawing, and anyone programming the machine, gets the side as well as the size.

Whatever convention you use, the rule is the same: the side of the bevel must be written, not implied. Agree on the sign with the shop once, and put the rule in the drawing notes.

Mirrored parts reverse the side

A plate and its mirror image have the bevel on opposite faces. Flip the drawing and the sign changes. This is why a mirrored plate with a bevel needs its own drawing, and why grouping identical parts must look at the 3D and not only at the outline.

Check it before the plate is cut

On every drawing with a bevel, check three things: the bevel appears in a view where its edge is visible, the dimension has both depth and angle, and the sign matches the face in the 3D model. It takes seconds per drawing, and it is the difference between a weld prep and a scrapped plate.

Do and don't

Do

• Show the bevel where its edge is a visible line.
• Write depth, angle and sign: 8x+25°.
• Give mirrored bevelled plates their own drawing.

Don't

• Don't write the angle alone.
• Don't dimension a hidden line.

Related: dimensioning holes and overall sizes with the Inventor API, left-hand parts.

Bevels are dimensioned and checked this way on every project we deliver. Send us a file to see it on your parts.