The K factor describes the neutral axis location relative to sheet thickness and helps calculate a flat pattern. It is a starting point for the unfolding calculation, not a universal setting that guarantees the finished flange dimensions. For production work, review it using an identified material and a measured trial fold.
SOLIDWORKS defines K factor as the neutral-axis distance from the inside face divided by material thickness. The purchasing and production question is how the chosen unfolding rule behaves with the actual material and process.
Freeze the trial conditions before changing the factor
Use a simple coupon with a known initial length. Record the material specification, measured thickness, grain orientation, intended bend and machine setup. Identify the drawing's dimension convention before comparing the trial with the model.
Choose a trial that can be measured reliably. A complex architectural profile may hide several interacting errors, making it difficult to decide whether a correction belongs in the unfolding rule, the programmed position or the bend sequence.
Read the calculation with the correct angle
For the usual circular-bend model, bend allowance is calculated from the bend angle, inside radius, thickness and K factor. The angle used is the angle through which the material bends. Do not silently substitute the finished opening angle. Autodesk's unfold reference documents the calculation.
As an illustrative calculation only, a 90-degree bend with a 1.0 mm thickness, 1.0 mm inside radius and an assumed K factor of 0.4 gives a bend allowance of about 2.20 mm. These invented inputs demonstrate arithmetic; they are not ARTITECT material settings or machine specifications.
Keep the trial record useful to the next operator
- Material identity. Suggested entry: Specification and batch reference
- Geometry. Suggested entry: Initial blank length, thickness, radius and angle convention
- Process. Suggested entry: Machine, setup and program revision
- Measurement. Suggested entry: Defined datums, instrument and measured result
- Decision. Suggested entry: Accepted rule or next controlled trial
Change one relevant variable at a time. If the measured angle is wrong, resolve that condition before assuming a blank-length correction will produce an acceptable part. Keep the first trial as well as the accepted trial so the reasoning can be reviewed.
Carry the result into a representative profile
Autodesk's calibration guidance recommends checking produced samples when establishing the factor. After the simple trial, propose a first article using a representative production profile and the intended material.
ARTITECT's machine functions describe CNC thickness adjustment and graphic sequence control. Discuss those functions against the trial profile; neither replaces verification of the blank calculation and finished dimensions.
Questions about K factor
Is 0.5 always the right value?
Do not treat a convenient default as a validated production rule. Review the actual process.
Can a correct K factor fix every dimensional error?
No. Check angle, datums, blank preparation and positioning as separate variables.
Can one accepted trial cover every material?
Define the range covered by the trial and review changes in material or process.
Should the trial use a full building profile first?
A simple coupon can make the initial calculation easier to assess. Follow it with a representative first article.
What should I send ARTITECT?
Submit your drawing and trial requirements, including material, thickness, working length and dimensional acceptance criteria. Ask for a folding setup discussion tied to that information.