The welding deposition rate is a critical metric in welding economics and productivity. It measures the amount of filler metal actually deposited into the weld joint over a specific period, typically expressed in pounds per hour (lbs/hr) or kilograms per hour (kg/hr). Calculating this rate helps project managers estimate completion times, consumable costs, and overall fabrication efficiency.
The Physics of the Calculation
This calculator determines the weight of the wire consumed based on its volume and density, then adjusts for process efficiency. The core logic follows this geometric formula:
Rate (lbs/hr) = Volume of Wire × Density × Efficiency
Where volume is derived from the cross-sectional area of the wire ($\pi \times r^2$) multiplied by the Wire Feed Speed (WFS). The formula used by this tool is:
Area: $\pi \times (\text{Diameter}/2)^2$
Volume/hr: Area $\times$ WFS (in/min) $\times$ 60 min/hr
Weight/hr: Volume/hr $\times$ Material Density
Net Rate: Weight/hr $\times$ (Efficiency % / 100)
Typical Process Efficiencies
Not all wire melts directly into the joint. Some is lost to spatter, slag, or stub ends (in stick welding). Use these guidelines for the "Efficiency" input:
Welding Process
Typical Efficiency
Notes
GMAW (MIG/MAG) – Solid Wire
95% – 99%
Very high efficiency, minimal spatter.
FCAW (Flux Cored) – Gas Shielded
80% – 85%
Loss due to slag formation and spatter.
SMAW (Stick)
55% – 65%
Significant loss due to stub ends and flux coating.
SAW (Submerged Arc)
99% – 100%
Near perfect efficiency, no spatter.
Why Monitoring Deposition Rate Matters
1. Cost Estimation: By knowing the deposition rate and the total weight of weld metal required for a project, you can accurately forecast the labor hours needed.
2. Productivity Analysis: Higher deposition rates usually lead to faster travel speeds, but they must be balanced against heat input requirements to prevent distortion or metallurgical issues.
3. Consumable Planning: Helps in ordering the correct amount of wire or electrodes, reducing waste and inventory costs.
function updateDensityHint() {
// Optional helper to visualize density change if needed,
// currently handled directly in calculation logic.
}
function calculateDeposition() {
// 1. Get Input Elements
var matSelect = document.getElementById('weldMaterial');
var diaInput = document.getElementById('wireDiameter');
var wfsInput = document.getElementById('wireFeedSpeed');
var effInput = document.getElementById('efficiency');
var resultBox = document.getElementById('resultContainer');
var resLbs = document.getElementById('resultLbs');
var resKg = document.getElementById('resultKg');
// 2. Parse Values
var density = parseFloat(matSelect.value);
var diameter = parseFloat(diaInput.value);
var wfs = parseFloat(wfsInput.value);
var efficiency = parseFloat(effInput.value);
// 3. Validation
if (isNaN(diameter) || diameter <= 0) {
alert("Please enter a valid wire diameter.");
return;
}
if (isNaN(wfs) || wfs <= 0) {
alert("Please enter a valid wire feed speed.");
return;
}
if (isNaN(efficiency) || efficiency 100) {
alert("Please enter a valid efficiency percentage (0-100).");
return;
}
// 4. Calculation Logic
// Radius = Diameter / 2
var radius = diameter / 2;
// Area (sq inches) = PI * r^2
var area = Math.PI * Math.pow(radius, 2);
// Volume per minute (cubic inches) = Area * IPM
var volPerMin = area * wfs;
// Volume per hour = VolPerMin * 60
var volPerHr = volPerMin * 60;
// Theoretical Weight (lbs/hr) = Volume * Density
var theoreticalRate = volPerHr * density;
// Actual Deposition Rate = Theoretical * Efficiency
var actualRateLbs = theoreticalRate * (efficiency / 100);
// Convert to Metric (1 lb = 0.453592 kg)
var actualRateKg = actualRateLbs * 0.453592;
// 5. Display Results
resLbs.innerHTML = actualRateLbs.toFixed(2) + " lbs/hr";
resKg.innerHTML = actualRateKg.toFixed(2) + " kg/hr";
resultBox.style.display = "block";
}