KEVOS® MAKEOS · Fabrication
Sheet-Metal Bracket: Flat Blank, Nesting, Bending Force and Cost
What flat blank, sheet yield, bending force and cost per part does this bent sheet-metal bracket have?
Cost build-up of a one- or two-bend sheet-metal part: developed flat length from outside dimensions with the bend allowance and deduction (K-factor), parts per sheet in the better orientation with spacing, material utilisation and cost per part, press brake force per bend, and labour cost from bend and blanking times with set-up spread over the batch.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Part | ||
| First flange (outside) | mm | Outside length of the first flange. |
| Web (outside) | mm | Outside length of the web between bends. |
| Second flange (outside, 0 = one bend) | mm | Outside length of the second flange (0 for an L-bracket). |
| Part width | mm | Width of the part along the bend line. |
| Thickness | mm | Material thickness. |
| Inside bend radius | mm | Inside radius of the bends. |
| K-factor | K-factor locating the neutral axis (about 0.33–0.45 for air bending). | |
| Bend angle | ° | Bend angle of each bend. |
| Sheet and material | ||
| Sheet length | mm | Length of the stock sheet. |
| Sheet width | mm | Width of the stock sheet. |
| Spacing and edge margin | mm | Spacing between blanks and at the sheet edge. |
| Density | kg/m³ | Material density. |
| Sheet price | $/kg | Price of the sheet per kilogram. |
| Tensile strength | MPa | Tensile strength of the sheet. |
| Press brake and labour | ||
| Die opening | mm | Opening of the bending die (6–12 × thickness). |
| Air-bending factor | Air-bending force factor (1.33 is common). | |
| Shop rate | $/h | Machine and labour rate. |
| Time per bend | s | Handling and bending time per bend. |
| Blanking time per part | s | Time to cut each blank. |
| Set-up time per batch | min | Set-up time for the batch. |
| Batch quantity | Parts in the batch. | |
Method and formulas
- Bend allowance BA = θ (R + k t); outside setback = (R + t) tan(θ ÷ 2); deduction = 2 × setback − BA (as the bend allowance tool).
- Flat length = sum of outside dimensions − bends × deduction.
- Parts per sheet = best of the two orientations of ⌊(L_s − gap) ÷ (blank + gap)⌋ × ⌊(W_s − gap) ÷ (width + gap)⌋.
- Bend force = k W t² UTS ÷ V; cost = sheet cost ÷ parts + rate × (bends × t_bend + t_blank) + set-up share.
- Example: the default bracket blanks at 172.8 × 100 mm, nests 161 per sheet and costs about 2.1571 each.
Limitations
- Rectangular blanks on a simple grid; true nesting software can do better.
- Holes, notches and finishing are not costed.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Quote a bent bracket or cover
- Choose sheet size for best yield
- Check press brake capacity for a part
Who it is for
- Estimators
- Fabrication supervisors
- Design engineers
What you get
- Flat blank and parts per sheet
- Bending force
- Cost per part
Interpreting the result
- Utilisation under about 75% suggests trying another sheet size or orientation.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 1346–1353. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
Open the Sheet-Metal Bracket: Flat Blank, Nesting, Bending Force and Cost calculator
