Rishiyanya Solutions - Advanced Foundry Formula & Calculator Library

Complete Foundry Formula + Calculator Tool — Guided Step-by-Step Mode V8

Use this as an initial engineering calculator. Every calculator now gives fresher-friendly input guidance, advisable values, high/low effects, formula meaning, step-by-step output and common risk checks. Final design must be confirmed by company standard, customer drawing, simulation/trial and senior approval.

New in this V6 version: every calculator now includes advisable/target value guidance, what happens if the result is high or low, common risks, checking points, plus previous formulas, calculation steps, alloy temperature data and formula library.

Calculator Groups

ChargeRecoveryYieldPouring TempSolidus/LiquidusGrade Temp DataChokeSprueGating RatioVelocityReynoldsModulusRiserChvorinovNeckChillsShrinkageDraftCore PrintAFSPermeabilityBinderSoakingPPMCp/Cpk

How to use every calculator now

1) Read the beginner input guide. 2) Enter values from drawing/lab/shop history. 3) Press Calculate. 4) Open/read the full step-by-step explanation below the result. 5) Compare low/high risk before using the value in production.

Symbols

W = weight, ρ = density, V = volume, A = area, M = modulus, t = time, g = 9.81 m/s², h = metallostatic head, Cd = discharge coefficient, C = mould constant, n = Chvorinov exponent.

🔥 Melting & Charge Calculators

Charge planning, alloy addition, recovery, melt loss, yield, furnace power and temperature.

1. Metal Weight from Volume

Find casting or gating weight from CAD/manual volume.

W = V × ρ × Qty

Volume

Volume unit

Density kg/m³

Quantity

2. Total Melt Required & Yield

Estimate total liquid metal and process yield.

Poured W = (Casting W×Qty + Gating/Riser W) × (1 + Loss%/100) Yield% = Good Casting W / Poured W ×100

Good casting wt / pc kg

Qty

Gating + riser kg

Melt/process loss %

3. Alloy Addition with Recovery

For FeCr, FeMn, FeSi, Ni, Mo, carburizer etc.

Addition kg = Heat W × Required Increase% / (Additive Element% × Recovery%) ×100

Heat weight kg

Required element increase %

Element in additive %

Recovery %

4. Two-Charge Material Mixing

Find kg of material A and B to hit target chemistry.

x = Total × (Target - B%) / (A% - B%) A kg = x, B kg = Total - x

Total charge kg

Target %

Material A %

Material B %

5. Pouring Temperature Estimate

Estimate tap/pour target after transfer loss.

Pour Temp = Liquidus + Superheat + Transfer Loss + Safety Margin

Liquidus °C

Required superheat °C

Ladle/transfer loss °C

Safety margin °C

6. Furnace Energy & Melting Time

Rough planning for power requirement.

Theoretical Heat = m×Cp×ΔT + m×Lf Actual kWh = Theoretical kWh / Efficiency Time hr = kWh / Furnace Power kW

Metal kg

ΔT °C

Cp kJ/kg°C

Latent heat kJ/kg

Efficiency %

Furnace power kW

🌊 Gating & Pouring Calculators

Choke, pouring time, sprue, gating ratio, velocity and flow checks.

1. Pouring Time

First estimate using weight factor.

t = K × √W

Poured weight W kg

K factor

2. Choke Area

Controls metal flow rate.

A = W / (ρ × Cd × t × √(2gh))

Poured weight kg

Density kg/m³

Pouring time sec

Effective head h m

Shape

3. Gating Ratio Split

Area split for pressurized/non-pressurized gating.

Sprue : Runner : Ingate = a : b : c Runner total = Choke × b/a, Ingate total = Choke × c/a

Choke/Sprue area cm²

Ratio S:R:I

No. runners

No. ingates

4. Sprue Taper

Avoid aspiration by tapering sprue.

A_top / A_bottom = √(h_bottom / h_top) [flow continuity approximation]

Bottom area cm²

Head at top mm

Head at bottom mm

Shape

5. Flow Velocity Through Area

Check ingate velocity.

Q = W/(ρ×t) v = Q/A

Poured weight kg

Density kg/m³

Time sec

Total area cm²

6. Reynolds Number Check

Rough flow regime check.

Re = ρ × v × D / μ

Density kg/m³

Velocity m/s

Hydraulic dia mm

Dynamic viscosity Pa·s

🧱 Riser / Feeding / Chill Calculators

Modulus method, Chvorinov, riser geometry, neck, feeding distance and chills.

1. Casting Modulus

Basic feeding design value.

M = V / A

Volume cm³

Cooling surface area cm²

2. Required Riser Modulus

Riser should freeze after casting hot spot.

M_riser = Factor × M_casting Typical factor 1.1 to 1.4 depending alloy/feeding difficulty.

Casting hot spot modulus cm

Safety factor

3. Cylindrical Riser Size

Calculates D and H from required modulus and H/D ratio.

V = πD²H/4 A_closed = πDH + πD²/2 A_open = πDH + πD²/4 M = V/A

Required M cm

H/D ratio

Type

4. Chvorinov Solidification Time

Compare casting and riser freezing time.

t = B × Mⁿ

Mould constant B

Modulus M cm

Exponent n

Result unit

5. Riser Feed Metal Volume

Check if riser has enough liquid feed volume.

Required feed volume = Casting volume × Shrinkage% Available feed = Riser volume × Feed efficiency%

Casting volume cm³

Volumetric shrinkage %

Riser volume cm³

Riser efficiency %

6. Feeder Neck Estimate

Initial neck size based on local section.

Round neck dia ≈ Factor × local section thickness Rectangular neck area ≈ width × height

Local section thickness mm

Factor

7. Guided Feeder Neck Thickness & Width Calculator

For freshers: this tool asks the important values one by one, gives default guideline ranges, then shows complete step-by-step feeder neck calculation. Use it for side/top feeder neck, rectangular/slot neck, or sleeve-to-casting neck.

How to use:
1) First find casting hot-spot modulus from the previous Casting Modulus calculator: M = Volume/Cooling Area.
2) If you do not know modulus, enter local section thickness and press Estimate M from thickness. This is only an approximate starting value for simple plate-like sections.
3) Select neck factor based on feeding difficulty. Then choose whether you want the tool to calculate both width & thickness, or solve one from your fixed practical value.

Rectangular/slot feeder neck assumption: V = W × T × L Cooling area A = 2 × L × (W + T) [end faces connected to casting/riser not counted] Neck modulus Mₙ = V/A = (W × T) / [2 × (W + T)] Required neck modulus: Mₙ(req) = Casting hot-spot modulus × neck factor Solve by W/T ratio r: T = 2M(r+1)/r, W = rT Solve width if thickness fixed: W = 2MT / (T − 2M) Solve thickness if width fixed: T = 2MW / (W − 2M)

A. Casting / alloy information

Alloy / difficulty guideline

Local section thickness near neck mm

Casting hot-spot modulus cm (best input)

Neck modulus factor

Or direct required neck modulus cm (optional)

Neck length / feed path L mm

Input guideline: For steel casting start neck factor 0.8–1.0. For a slot neck, W/T ratio 1.5–3.0 is a practical starting band. If neck is too thin it freezes early; if too thick it becomes hard to cut and may create local hot spot.

B. What should the tool solve?

Solve method

W/T ratio r (used in beginner mode)

Fixed thickness T mm (used if selected)

Fixed width W mm (used if selected)

Density g/cm³ for neck weight

Show full step-by-step calculation and fresher explanation

8. Number of Risers by Feeding Distance

First layout estimate.

N = ceil(Length / Feeding Distance) ceil means round up to next whole number.

Length to feed mm

Feeding distance mm

Feeding type

Extra safety riser

9. Chill Contact Area

Approximate chill sizing for hot spot.

Chill contact area = Hot spot area × severity factor

Hot spot area cm²

Severity factor

📐 Pattern / Core / Mould Calculators

Shrinkage, machining allowance, draft, core print and mould box estimates.

1. Pattern Dimension

Pattern size from final drawing dimension.

Pattern dim = Final dim + Machining allowance + Shrinkage allowance Shrinkage allowance = Final dim × shrinkage mm/m / 1000

Final dimension mm

Shrinkage mm/m

Machining allowance / side mm

No. machined sides

2. Draft / Taper Allowance

For pattern withdrawal.

Draft per side = Height × tan(angle)

Pattern height mm

Draft angle degree

3. Core Print Bearing Pressure

Check if core print support is adequate.

Bearing pressure = Core weight / Core print bearing area

Core weight kg

Bearing area cm²

4. Mould Box Sand Requirement

Estimate sand weight required.

Sand volume = Flask volume - Pattern volume Sand weight = Sand volume × bulk density

Flask L mm

Flask W mm

Flask H mm

Pattern volume cm³

Sand bulk density kg/m³

🏖️ Sand System Calculators

AFS, permeability, binder, moisture and sand reclamation.

1. Permeability Number

Standard sand venting indicator.

P = V × H / (p × A × t)

Air volume V cm³

Specimen height H cm

Pressure p g/cm²

Area A cm²

Time t min

2. AFS Grain Fineness Number

Enter retained % and multiplier pairs separated by lines: retained,multiplier.

AFS GFN = Σ(retained % × multiplier) / Σ(retained %)

Retained %, Multiplier

3. Binder / Catalyst Quantity

For no-bake/core sand preparation.

Binder kg = Sand kg × Binder% /100 Catalyst kg = Binder kg × Catalyst% /100

Sand kg

Binder % on sand

Catalyst % on binder

4. Moisture Addition / Removal

Water to add to reach target moisture.

Water add kg = Sand kg × (Target% - Current%) / (100 - Target%)

Sand kg

Current moisture %

Target moisture %

🌡️ Heat Treatment Calculators

Soaking time, heating/cooling rate, furnace load and thermal expansion.

1. Soaking Time

Initial estimate based on section thickness.

Soaking time = Base time + Thickness × min/mm

Max section thickness mm

Minutes per mm

Base time min

2. Heating / Cooling Rate Time

Estimate time for controlled temperature change.

Time hr = |Final Temp - Start Temp| / Rate °C/hr

Start °C

Final °C

Rate °C/hr

3. Thermal Expansion / Contraction

Dimensional change during heating/cooling.

ΔL = α × L × ΔT

Original length mm

Coefficient α /°C

ΔT °C

🧩 Lap / Cold Shut / Misrun & Weld Repair Calculators

Use this page when casting has lap/cold shut/misrun risk or when weld repair/groove/bevel/preheat planning is required. Final repair must follow approved WPS/PQR, customer specification, drawing acceptance criteria and NDT plan.

Important: Cold shut/lap normally comes when two metal fronts meet but do not fuse; misrun happens when metal fails to fill the cavity completely. Common controls are pouring temperature, pouring speed/time, fluidity, venting and gating design.

1. Lap / Cold Shut / Misrun Risk Index

Quick red/yellow/green check using flow length, thin section, temperature margin and pouring time.

Risk score = Flow factor + Thin section factor + Low superheat factor + Slow pouring factor + Venting factor

Longest metal flow length mm

Minimum section thickness mm

Actual pouring temp °C

Liquidus °C

Actual pouring time sec

Target pouring time sec

Venting / air escape condition

2. Fluidity / Flow Length Corrected Estimate

Estimate expected flow length after temperature and thickness change from shop trial.

L₂ = L₁ × (t₂/t₁)^0.5 × (Superheat₂/Superheat₁)

Trial flow length L₁ mm

Trial thickness t₁ mm

New thickness t₂ mm

Trial superheat °C

New superheat °C

3. Minimum Pouring Temperature for Lap Avoidance

Back-calculate target temperature considering liquidus, required superheat, transfer loss and thin-section safety margin.

T_target = Liquidus + required superheat + ladle loss + mould filling loss + safety margin

Liquidus °C

Required superheat °C

Ladle/transfer loss °C

Mould filling heat loss °C

Thin/long flow safety margin °C

4. Weld Repair Deposit & Electrode/Filler Requirement

For defect cavity filling after grinding/gouging. Add extra for overfill and losses.

Deposit kg = Groove volume cm³ × density g/cm³ /1000 × (1 + overfill%) Consumable kg = Deposit kg / deposition efficiency

Groove length mm

Average width mm

Average depth mm

Shape factor

Metal density g/cm³

Overfill + grinding allowance %

Deposition efficiency %

5. Groove / Bevel Opening Calculator

Estimate top width for V-groove repair or assembly bevel.

Top width = Root width + 2 × depth × tan(included angle/2)

Groove depth mm

Included angle degree

Root width / bottom radius allowance mm

Side margin each side mm

6. Carbon Equivalent & Preheat Suggestion

Screening calculator for steel casting weld repair crack risk. Use approved WPS for actual production.

CE(IIW) = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

C %

Mn %

Cr %

Mo %

V %

Ni %

Cu %

7. Welding Heat Input

Useful for repair WPS monitoring and interpass control.

Heat input kJ/mm = (V × A × 60 × efficiency) / (1000 × travel speed mm/min)

Voltage V

Current A

Travel speed mm/min

Process efficiency

8. Weld Pass Count Estimate

Estimate number of passes/layers from groove volume and average bead size.

Passes = ceil(Total groove area / bead area per pass)

Groove cross-section area mm²

Average bead area/pass mm²

9. Repair Decision Helper

Simple decision support for lap/cold shut/weld repair based on depth, location and acceptance level.

Defect type

Defect depth mm

Section thickness mm

Location criticality

🧪 Foundry Lab Testing Calculators

Laboratory support for chemistry, mechanical testing, sand/lab control, hardness, impact, microstructure and test reporting. Use for daily lab decisions; final acceptance must follow customer drawing, ASTM/ISO/EN/internal standard.

Lab control rule: Always record heat no., sample type, sample location, instrument calibration status, standard used, operator, date/time and retest reason. Never change chemistry only from one doubtful reading; confirm with proper sample preparation and repeat test.

1. Chemistry Correction After Spectro

Find required alloy addition to raise an element from actual to target.

Addition kg = Heat W × (Target% − Actual%) × 100 / (Element in additive% × Recovery%)

Heat weight kg

Actual %

Target %

Element in additive %

Expected recovery %

2. Dilution / Contamination Check

Estimate corrected element when sample is diluted/mixed with another material.

Final % = (W₁×C₁ + W₂×C₂) / (W₁+W₂)

Main sample weight g

Main chemistry %

Contamination / addition weight g

Contamination chemistry %

3. Tensile Test Calculator

Calculate UTS, yield strength, elongation and reduction of area.

UTS = Pmax/A₀; YS = Py/A₀; El%=(Lf−L0)/L0×100; RA%=(A0−Af)/A0×100

Original dia mm

Final dia mm

Gauge length L0 mm

Final length Lf mm

Max load kN

Yield load kN

4. Charpy Impact Average

Average 3 impact values and compare with minimum requirement.

Average J = (J1+J2+J3)/3; Low specimen check = min(J)

Required average J

Required single minimum J

5. Hardness Average & Uniformity

Average multiple readings and identify variation.

Average = Σ readings / n; Range = Max − Min

Hardness readings, comma separated

Minimum allowed

Maximum allowed

6. Nodularity / Graphite Lab Check

Simple ductile iron nodularity and nodule density calculation from image count.

Nodularity% = Nodular graphite count / Total graphite count ×100\nNodule density = Nodule count / Field area

Nodular graphite count

Total graphite count

Nodule count

Field area mm²

7. Lab Test Frequency / Sample Quantity

Plan required test samples for heat/lot release.

No. of samples = ceil(Lot Qty / Frequency Qty) × Tests per interval

Lot quantity / heat weight

Frequency per quantity

Tests per interval

8. Lab Release Decision Helper

Decision reminder for chemistry, mechanical, hardness and NDT release.

Chemistry status

Mechanical status

NDT / visual status

⚙️ Fettling / Finishing Calculators

Riser/runner cutting, grinding, shot blasting, finishing allowance, fettling cycle time, dust load and repair blending calculations. Use these for production planning and method improvement.

Safety: Fettling involves hot work, silica/metal dust, flying particles, noise and vibration. Use guards, PPE, dust extraction, lifting plan, hot-work permit and approved cutting/grinding wheels.

1. Riser / Runner Cutting Time

Estimate cutting time from cut area and cutting speed.

Cut area = thickness × cut length\nTime min = Cut area / Cutting rate

Total cut length mm

Average thickness mm

Cutting rate mm²/min

Setup/handling min

2. Grinding Time & Stock Removal

Estimate grinding time for pads, riser marks and weld blend.

Removal volume = Area × Stock\nTime = Volume / MRR + handling time

Area to grind cm²

Average stock mm

Grinding MRR cm³/min

Handling min

3. Grinding Wheel Consumption / Cost

Estimate wheel quantity and cost from metal removal.

Wheel required kg = Metal removed kg / G-ratio\nCost = Wheel required × Rate

Metal removed kg

G-ratio kg metal/kg wheel

Wheel cost per kg

4. Shot Blasting Time

Estimate blasting cycle time from casting surface area and machine coverage rate.

Time = Surface area / Effective coverage rate + loading/unloading

Surface area m²

Coverage rate m²/min

Efficiency %

Load/unload min

5. Fettling / Grinding Allowance Check

Check whether finishing will violate final dimension or machining allowance.

Remaining allowance = Actual size − Final required size − Removed stock

Actual size before fettling mm

Final required size mm

Stock to remove mm

Minimum machining allowance mm

6. Fettling Cycle Time / Manpower

Plan manpower from cutting, grinding, blasting and inspection time.

Total time/pc = Σ operation time\nOutput/shift = Available man-min / Time per pc

Cutting min/pc

Grinding min/pc

Blasting min/pc

Inspection/handling min/pc

Operators

Available min/shift/operator

7. Dust Load Estimate

Rough estimate for dust collection planning.

Dust kg = Metal removed kg × Dust generation % / 100

Metal removed kg/shift

Dust generation %

Collection efficiency %

8. Fettling Inspection Checklist Helper

Generate key checks after fettling.

Casting criticality

✅ Quality / NDT / Defect Calculators

Rejection, PPM, sampling, Cp/Cpk and defect RCA helper.

1. Rejection %

Rejection% = Rejected Qty / Total Qty ×100

Total qty

Rejected qty

2. Defect PPM

PPM = Defects / Opportunities × 1,000,000

Defects

Total opportunities

3. Cp / Cpk

Capability from measured process.

Cp=(USL-LSL)/(6σ) Cpk=min((USL-Mean)/(3σ),(Mean-LSL)/(3σ))

USL

LSL

Mean

Std dev σ

4. Defect RCA Helper

Select defect and get probable causes and actions.

Defect

🔁 Unit Converters

Quick shop-floor conversions.

Temperature

°C

Output

Length

Value

From

Hardness Approx Guide

Approximate only. Use certified conversion chart for acceptance.

🌡️ Alloy Grade Temperature Data

Grade-wise approximate Solidus, Liquidus, melting interval and pouring temperature range for quick foundry planning. These values are typical reference ranges only; exact temperature changes with chemistry, carbon equivalent, section thickness, furnace practice, mould material, ladle loss and customer/internal standard.

How to use: Select a grade to view its temperature window. Press copy button to send liquidus into the existing Pouring Temperature and Lap Avoidance calculators. Use actual lab chemistry/thermal analysis for final production.

1. Grade Temperature Lookup

Choose category and grade. The table below is also searchable by the left search box.

Category filter

Grade

2. Grade-Based Pouring Target Calculator

Uses selected grade liquidus average + superheat + transfer loss + safety margin.

Target pouring temp = selected liquidus average + superheat + transfer loss + safety margin

Selected grade liquidus avg °C

Superheat °C

Ladle / transfer loss °C

Safety margin °C

3. What is Solidus / Liquidus?

Melting interval = Liquidus − Solidus Superheat = Pouring temperature − Liquidus Temperature margin at metal front ≈ Pouring temp − heat loss − Liquidus

Solidus: below this, alloy is fully solid. Liquidus: above this, alloy is fully liquid. Between solidus and liquidus, alloy is mushy/semi-solid. Wide freezing range alloys need stronger feeding attention.

Temperature Data Table

Use as initial shop-floor planning data. For acceptance, use material specification, supplier data sheet, thermal analysis or calibrated pyrometer records.

Category	Grade	Standard / Common Name	Solidus °C	Liquidus °C	Melting Range °C	Typical Pouring Range °C	Shop-floor Note

📊 Foundry Technical Data Page

One-page reference for common input parameters used across the calculators. Values are practical starting ranges only. Final values must be fixed from customer specification, alloy standard, casting geometry, simulation/trial, and your company methoding standard.

How to use: Pick the nearest alloy/process, enter the suggested starting value in the calculator, then validate with actual shop data. For critical pressure, safety, nuclear, valve, petrochemical, railway or export castings, use approved procedure values only.

Quick Search in Technical Data

Type shrinkage, riser, H/D, gating, sand, weld, lab, fettling, etc.

1. Pattern Shrinkage / Contraction Allowance

Use in Pattern Dimension calculator. Shrinkage depends on alloy, chemistry, mould rigidity, casting shape, restraint and heat treatment.

Alloy / Material	Typical shrinkage allowance	mm/m	Use / Advice	If low	If high
Grey cast iron	0.8% to 1.1%	8 to 11	Common start: 10 mm/m	Casting may come undersize after machining	Oversize casting, excess machining, high cost
SG / ductile iron	0.9% to 1.3%	9 to 13	Common start: 10 to 12 mm/m	Machining stock shortage	Extra fettling/machining
Carbon / low alloy steel casting	1.8% to 2.2%	18 to 22	Common start: 20 mm/m	Dimensional rejection after HT/machining	Heavy casting, machining waste
High alloy / stainless steel casting	2.0% to 2.6%	20 to 26	Common start: 22 to 24 mm/m	Undersize after solution treatment	Oversize, high machining time
Aluminium sand casting	1.0% to 1.3%	10 to 13	Common start: 12 mm/m	Undersize casting	Excess machining, mismatch issue
Copper alloys / bronze	1.4% to 2.0%	14 to 20	Bronze/NAB usually needs higher than aluminium	Bore/face undersize	Extra material and cost

2. Riser / Feeding Design Parameters

Parameter	Typical value	Advisable use	Low value risk	High value risk
Riser modulus safety factor	1.10 to 1.40 × casting hot-spot modulus	Start 1.2 for normal steel; 1.3 to 1.4 for difficult hot spots	Riser freezes early, shrinkage porosity	Low yield, more cutting/fettling
Cylindrical riser H/D ratio	0.8 to 1.5	Start 1.0 for blind/open cylindrical riser	Low modulus, early freezing	Tall riser, mould height issue, high metal loss
Riser efficiency	Open riser 10 to 15%; blind/insulated 15 to 30%; exothermic 30 to 60%	Use lower value when unsure	Insufficient feed metal estimate	Oversized riser, poor yield
Feeder neck factor	0.6 to 1.0 × local section thickness	0.8 × thickness is normal first trial	Neck freezes/chokes, shrink near neck	Difficult knockout, heavy grinding
Chvorinov exponent n	Usually around 2	Use 2 for comparison of similar moulds	Wrong freezing prediction	Wrong freezing prediction
Chill severity factor	0.5 mild, 1.0 normal, 1.5 severe, 2.0 very severe	Use only with directional solidification plan	Hot spot remains, shrinkage	Chill crack, hard spot, machining issue
Steel casting volumetric shrinkage for feed check	3% to 6%	Use 5% for first estimate	Underfed casting	Oversized riser
Aluminium casting volumetric shrinkage for feed check	4% to 7%	Use alloy and process specific data	Shrink porosity	Low yield

3. Gating / Pouring Parameters

Parameter	Typical value	Advisable use	If low	If high
Pouring time K factor, t=K√W	1.0 simple; 1.3 normal; 1.7 heavy/complex; 2.0 thin/critical	Increase for complex/thin castings	Fast turbulent filling, erosion, inclusions	Cold shut, lap, misrun
Discharge coefficient Cd	0.6 to 0.9	Use 0.8 for clean tapered sprue/gating	Choke area becomes too large if wrongly assumed	Choke area becomes too small if wrongly assumed
Effective metallostatic head	0.15 to 0.60 m common	Measure from metal level to choke/ingate level	Slow filling, cold shut	High velocity, mould erosion
Gating ratio - pressurized	1:0.75:0.5 to 1:1:1	Used for ferrous when dross control is managed	Choking/short run if too restrictive	Turbulence if uncontrolled
Gating ratio - non-pressurized	1:2:2, 1:3:3, 1:4:4	Good for reducing velocity and turbulence	Flow restriction if area too small	Low velocity, cold shut if too large/slow
Ingate velocity	Ferrous rough start 0.4 to 1.5 m/s; aluminium often lower	Keep smooth, avoid direct impingement	Misrun/cold shut	Erosion, gas aspiration, inclusions
Reynolds number	Lower is better; molten metal often turbulent	Use as warning, not final acceptance	Very low may not fill thin section	Oxide entrainment, erosion, sand wash
Sprue taper	Top larger than bottom	Design for full sprue and no aspiration	Aspiration, gas pickup	Excess metal and turbulence at base

4. Alloy Temperature / Superheat Parameters

Parameter	Typical value	Advisable use	If low	If high
Superheat above liquidus - cast steel	40 to 90 °C	Thin/long flow needs higher; heavy simple casting lower	Lap, cold shut, misrun	Burn-on, penetration, gas, shrinkage tendency, grain coarsening
Superheat - cast iron	50 to 120 °C depending iron	Control with inoculation fading and section size	Misrun, poor filling	Fading, shrinkage, sand fusion
Superheat - aluminium	30 to 80 °C	Avoid excessive holding temperature	Cold shut, misrun	Hydrogen pickup, oxidation, dross
Ladle/transfer temperature loss	10 to 60 °C	Measure actual shop loss by route and ladle type	Underestimated loss causes cold defects	Overestimated loss causes overheating
Safety margin for thin/long flow	10 to 30 °C	Use when longest flow length or thin wall is critical	Lap/cold shut	Overheating defects

5. Pattern / Core / Mould Parameters

Parameter	Typical value	Advisable use	If low	If high
Machining allowance - small casting	2 to 5 mm/side	Based on size, process, drawing and distortion	Machining cleanup failure	Extra machining cost
Machining allowance - heavy steel casting	5 to 15+ mm/side	Use more for large/HT distorted castings	Black spots after machining	Weight/cost increase
Draft angle external	0.5° to 2°	Use more for deep manual moulding	Pattern drag, sand breakage	Extra stock, dimensional issue
Draft angle internal pocket	1° to 3° or more	Internal walls need more draft	Mould damage during withdrawal	Excess machining/shape change
Core print bearing pressure	Keep low and stable; validate by core weight/support	Increase print area for heavy cores	Core shift, core breakage	Large print removal/fettling
Sand bulk density	Green sand ~1400 to 1700 kg/m³; chemically bonded ~1500 to 1800 kg/m³	Use actual shop compacted density	Underestimate sand requirement	Overestimate sand/cost

6. Sand System Parameters

Parameter	Typical value	Advisable use	If low	If high
AFS GFN - steel castings	45 to 65 common	Coarser for permeability, finer for surface finish	Rough surface/penetration if too coarse	Low permeability, gas defects
AFS GFN - iron castings	50 to 70 common	Balance finish and venting	Rough surface	Gas/blowholes
Green sand moisture	2.5% to 4.5%	Control with compactability	Friable mould, erosion	Blowholes, scab, low strength
Bentonite/clay	6% to 10% depending system	Use active clay testing	Low green strength	Poor permeability, high moisture demand
No-bake resin binder	0.8% to 1.5% on sand	Use supplier recommendation and strength test	Core/mould breakage	Gas, cost, poor collapsibility
Catalyst on binder	20% to 60% depending resin/temperature	Adjust for strip time and bench life	Slow curing, weak core	Short bench life, brittle core
Permeability number	Application-specific; higher for venting	Track trend by sand system	Gas defects	Rough surface/metal penetration if too coarse

7. Heat Treatment Parameters

Parameter	Typical value	Advisable use	If low	If high
Soaking time rule	1 to 2 min/mm + base time	Use section thickness and furnace load	Non-uniform structure/properties	Grain growth, scaling, cost
Heating rate for heavy casting	25 to 100 °C/hr depending alloy/section	Slower for complex/high alloy/heavy sections	Long cycle	Thermal crack/distortion
Cooling rate control	As per material standard/WPS	Critical for hardness and mechanical property	Soft/incorrect structure	Cracking, high hardness, distortion
Thermal expansion coefficient	Steel ~12×10⁻⁶/°C; aluminium ~23×10⁻⁶/°C	Use for fixture and distortion allowance	Underestimate expansion movement	Over-conservative fixture gap

8. Weld Repair / Lap Repair Parameters

Parameter	Typical value	Advisable use	If low	If high
Groove included angle	45° to 75°	60° is common first estimate	Poor access, lack of fusion	High weld volume, distortion
Root width / bottom opening	2 to 5 mm typical	Allow full cleaning and access	Lack of fusion/slag trap	More weld metal
Weld overfill allowance	10% to 25%	Use 15% for initial consumable estimate	Insufficient fill after grinding	Extra grinding and heat input
SMAW deposition efficiency	55% to 70%	Use 60% to 65% for planning	Consumable shortage if overestimated	Excess consumable planning
Carbon equivalent CE	<0.40 easier; 0.40-0.60 moderate; >0.60 high risk	Higher CE needs preheat/interpass control	No preheat may crack	Too much preheat may distort/slow production
Welding heat input	Follow WPS; often controlled by process/alloy	Monitor voltage/current/travel speed	Lack of fusion	HAZ cracking, distortion, coarse grain

9. Lab / Quality / Fettling Parameters

Parameter	Typical value	Advisable use	If low	If high
PPM target	Lower is better; customer-specific	Track by defect family and customer	Good if truly low	Customer complaint, RCA required
Cp / Cpk	1.00 minimum; 1.33 common capable; 1.67 strong	Use for stable measured process only	Process not capable	Good, but verify measurement system
Hardness reading range	Customer/spec defined	Check average and max-min variation	Soft casting may fail wear/strength	Machining difficulty/crack risk
Grinding MRR	Depends wheel/tool; 3 to 15 cm³/min rough planning	Use measured shop rate by operator/tool	Underestimates time if too high assumed	Overestimates manpower if too low assumed
Shot blast coverage rate	Machine-specific	Use actual m²/min after loading efficiency	Underblasted surface	Overblast, surface roughening, time loss
Dust extraction efficiency	As high as practical; verify with safety norms	Use PPE + LEV + housekeeping	Health/silica/metal dust risk	Good, but maintain filters

Common Starting Values for Calculator Inputs

Steel shrinkage = 20 mm/m SG iron shrinkage = 10 to 12 mm/m Riser modulus factor = 1.2 normal, 1.3 severe Riser H/D = 1.0 first estimate Feeder neck = 0.8 × local section thickness Rectangular neck modulus target = 0.7 to 1.0 × local hot-spot modulus; W/T ratio 1.5 to 3.0 start Pouring K = 1.3 normal, 1.7 complex Cd = 0.8 for normal gating calculation No-bake binder = 1.0% to 1.3% on sand Green sand moisture = 3% to 4% Draft external = 1°; internal = 2° Weld groove angle = 60°; overfill = 15%; SMAW efficiency = 65%

📚 Foundry Formula Library

Main formulas used inside this tool. Use this page for training and audit explanation.