KEVOS® MAKEOS · Fabrication
Angle Ring Cut Plan (Cut Length, Bars, Joints, Waste, Mass)
How long do I cut angle or flat bar to roll into rings for this shell, how many stock bars and joints do I need, and how much is wasted?
Cutting plan for rolled stiffening or flange rings of angle or bar fitted inside or outside a shell: cut length from the shell diameter corrected to the section’s neutral axis (as the length of angle bent to a ring tool), joints per ring when one ring needs more than one stock length, stock bars for the quantity with saw kerf, waste, mass of each ring and the material cost, with the waste checked against your limit.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Correction from | choice | Whether the correction uses the neutral-axis distance or a length constant (as the ring length tool). |
| Section is | choice | Whether the ring sits inside or outside the shell. |
| Shell diameter at the back of the section | mm | Shell diameter at the back of the angle or bar. |
| Back of section to neutral axis | mm | Distance from the back of the section to its neutral axis. |
| Length constant | mm | Length constant from your section data. |
| Stock and cost | ||
| Rings needed | Number of rings. | |
| Stock bar length | m | Length of the stock bars. |
| Saw kerf and end trim per cut | mm | Material lost per cut, including end trim. |
| Section area | mm² | Cross-section area of the angle or bar. |
| Density | kg/m³ | Density of the material. |
| Material price | $/kg | Price of the material. |
| Largest waste | % | Largest share of bought length you accept as waste. |
Method and formulas
- Cut length = π D ∓ 2π x (or ∓ the length constant), minus for a ring inside the shell (as the length of angle bent to a ring tool).
- Joints per ring = 1 if one bar covers it, otherwise ⌈length ÷ stock⌉; total length = rings × (length + joints × kerf); bars = ⌈total ÷ stock⌉.
- Waste = 1 − rings × length ÷ (bars × stock); mass = length × area × density.
- Example: cut 19,010 mm per ring with 4 joint(s); 13 bars of 6 m, 2.514% waste; each ring 134.3 kg.
Limitations
- Cut length to the neutral axis; rolling springback and joint preparation need trial allowances.
- Waste assumes offcuts are not reused.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Order angle for tank or duct stiffening rings
- Cut blanks for rolled flanges
- Estimate joints and waste for a ring job
Who it is for
- Boilermakers
- Fabrication supervisors
- Estimators
What you get
- Cut length and neutral diameter
- Joints per ring, stock bars and waste
- Ring mass and cost
Interpreting the result
- Longer stock bars cut the number of joints; check what lengths the mill supplies.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 2593. 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 Angle Ring Cut Plan (Cut Length, Bars, Joints, Waste, Mass) calculator
