Forging mass (cylinder or block), up to 6 round-bar diameters for purchasing, cut length with classic Math.round, upset factor 1.3 and dynamic metal loss. Engineering report and PDF for ordering stock.
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Часті запитання
What is upset ratio Y = 1.3 for forging?+
Y = 1.3 is a typical upset allowance: forging stock mass exceeds finished forging mass. The calculator applies it when sizing round bar for supply.
How is round bar chosen for forging supply?+
From billet mass and cut length the calculator suggests up to six standard round diameters convenient for purchasing.
Where do +3.5% and +6% process losses come from?+
Indicative metal loss for burn-off, trim and forging scrap. They increase purchase mass and lower UF for batch planning.
Norming parameters
Material selection for round bar, hexagon, forgings and sheet. For sheet — standard thicknesses, commercial sheet nesting and a PDF report.
Blank material
Structural steel (7.85 g/cm³)
Step 1. Forging shape and dimensions
Step 2. Cutting
Piece-by-piece on the saw for forging. Facing and saw kerf allowances are not specified — they are covered by the upsetting ratio and process losses (+3.5% for an upset disk, +6% for shafts and blocks).
Step 3. Round bar to order from the supplier
Available purchasing options (sourcing choice)
Round ∅ (mm)
Cut length (mm)
Billet mass (kg)
Process note
∅ 50
125
1.93
Standard drawing-out (large round)
∅ 60
90
2.00
Standard drawing-out (large round)
∅ 70
65
1.96
Standard drawing-out (large round)
∅ 80
50
1.97
Standard drawing-out (large round)
∅ 90
40
2.00
Standard drawing-out (large round)
Up to 5 common sizes (steps of 10 / 20 / 50 mm, L/Ø ≤ 2.5). ∅ 50–90 mm. Click a row to use it for the report and PDF.
Affects batch weight and UF.
Engineering report
Summary of material norming for the given batch
Forging envelope
Ø50 × L 120 mm
Cylindrical (shaft / disk) · mass 1.85 kg
Selected stock (sourcing)
Round ∅ 50 mm × 125 mm
1.927 kg · min. forging Ø 57.009 mm · up to ∅ 90 mm
Other purchasing options
∅60×90 mm (1.998 kg) · ∅70×65 mm (1.964 kg) · ∅80×50 mm (1.973 kg) · ∅90×40 mm (1.998 kg)
5 options available in the purchasing range
Engineering solution
To obtain the specified forging, order: Round bar ∅ 50 mm, length 125 mm. Blank weight: 1.93 kg.
Blank weight (1 pc)
1.927 kg
Upsetting Y = 1.3 · process losses +3.5% (disk) / +6% (shaft, block)
Total blank weight per batch (gross)
19.27 kg
Material purchase mass for the entire batch
Clean weight of one finished part (net)
1.85 kg
Forging mass: cylinder Ø50 × 120 mm
Chip / waste weight
0.77 kg
Batch clean weight: 18.5 kg
Utilization factor (UF)
96%
High UF — waste is within the norm.
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Calculation methodology and material consumption norming
The calculator computes the forging mass from its geometry, adds the upsetting ratio Y = 1.3 and process metal losses, then suggests round bar to order from the supplier.
What the algorithm accounts for
Upsetting and losses: Y = 1.3; +3.5% for a disk under upsetting; +6% for shafts and blocks. Separate saw allowances are not specified — these coefficients cover them.
Round bar for sourcing: up to six common diameters with the cut length (rounded to 5/10 mm) for the billet mass per batch.
Mathematical basis of the calculation
The geometric forging mass is calculated as for a disk (cylinder) or a block (cuboid). The upsetting ratio and process losses are applied to it before selecting the round bar.
m [kg] = V [mm³] × ρ [g/cm³] / 10⁶
Reference density table
Material
ρ, g/cm³
Application
Structural steel
7.85
Forging / round bar for forging
Steel (7.85 g/cm³) is used by default.
Formulas
Cylindrical forging
m_geom = (π × D² / 4) × L × ρ / 10⁶
Rectangular forging (block)
m_geom = L × W × H × ρ / 10⁶
Billet mass with upsetting and losses
m_gross ≈ m_geom × Y × k_loss
Y = 1.3; k_loss = 1.035 (disk under upsetting) or 1.06 (shaft / block).
Round bar selection
Standard round bar diameters are selected from the billet mass; cut length = mass / (cross-section area × ρ), with process rounding.
Notation: D, L, W, H — forging dimensions (mm); Y — upsetting ratio; ρ — density; m — mass (kg).
