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MIG Deposition Rate

Calculate MIG filler metal deposition rate in lbs/hr from wire diameter and feed speed. Estimate arc-on time and wire consumption for production welding.

Machine Setup

Wire Diameter

Inches

Wire Feed Speed

IPM

Process Type

Target Weld Weight (Total)

lbs

IPM vs Deposition

Deposition rate is the actual weight of filler metal added to the weld joint per hour of continuous arc time. While Wire Feed Speed (IPM) controls the volume of wire entering the puddle, the Wire Diameter has an exponential effect on the total weight because it increases the area ($D^2$) of the wire's cross-section.Flux Core (FCAW) has a lower efficiency (85%) because some of the wire's weight is flux that turns into slag or smoke, rather than staying in the weld.

Deposition Rate

4.57 lbs/hr

Filler Metal Output

Target Arc Time

2.19Hours

Required "Trigger-On" time for 10 lbs

Estimated Consumables10.53 lbs

Total spool weight needed (includes loss)

For estimation purposes only. Always consult a licensed professional before beginning work. Full Trade Safety Notice →

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What is MIG Deposition Rate: The Production Welding Speedometer?

Deposition rate is the weight of filler metal actually deposited into the weld joint per hour of arc-on time. It is the single most important metric for production welding because it directly determines how fast a welder fills a joint, how many labor hours a job requires, and how much wire the shop must purchase.

Mathematical Foundation

Deposition Rate (Steel Solid Wire)

DR = 13.1 \times D^2 \times WFS \times Eff

DR

= Deposition Rate (lbs/hr)

D

= Wire Diameter (inches)

WFS

= Wire Feed Speed (inches per minute)

Eff

= Process Efficiency (0.95 for GMAW solid wire)

13.1

= Constant derived from steel density (0.283 lbs/in³) × π/4 × 60 min/hr

Laws & Principles

GMAW Solid Wire Efficiency: 93-98% of the wire that feeds through the gun lands in the weld joint. The remaining 2-7% is lost to spatter.
FCAW Efficiency: Only 80-86% of the wire weight is deposited. The flux core converts to slag (14-20% by weight), which is chipped off and discarded.
Diameter Rules Everything: Doubling wire diameter quadruples the cross-sectional area and therefore quadruples the deposition rate at the same wire feed speed. Switching from 0.035 to 0.045 wire increases deposition by 65% at the same WFS.
Arc-On Time ≠ Shift Time: A typical production welder has 25-35% arc-on factor (actual welding time vs. total shift time). The rest is fit-up, grinding, repositioning, and breaks. To estimate real completion time, divide arc-on time by the arc-on factor.

Step-by-Step Example Walkthrough

" Running 0.035-inch ER70S-6 solid wire at 300 IPM wire feed speed. "

1. Apply formula: DR = 13.1 × (0.035)² × 300 × 0.95
2. DR = 13.1 × 0.001225 × 300 × 0.95
3. DR = 13.1 × 0.3675 × 0.95 = 4.57 lbs/hr
4. To deposit 10 lbs of weld metal: 10 / 4.57 = 2.19 hours arc-on time
5. At 30% arc-on factor: 2.19 / 0.30 = 7.3 hours total shift time

Final Result: Deposition rate is 4.57 lbs/hr. Plan for 2.2 hours of arc time, or roughly 7.3 hours of actual shift time at 30% arc-on factor.

Quick Answer: How Many Pounds Per Hour Does MIG Welding Deposit?

MIG deposition rate depends on wire diameter and feed speed. A common setup — 0.035" wire at 300 IPM — deposits about 4.6 lbs/hr. Larger wire deposits more: 0.045" at 300 IPM = 7.6 lbs/hr. The formula is DR = 13.1 × D² × WFS × Efficiency. This calculator gives you the exact deposition rate, total wire weight needed, and estimated arc-on time for any wire size and feed speed combination.

Deposition Rate Formula

Deposition (lbs/hr) = 13.1 × D² × WFS × Efficiency

The 13.1 constant comes from: steel density (0.283 lbs/in³) × π/4 (circular area) × 60 (min to hr). For stainless steel, use 13.4. For aluminum, use 4.6. These constants account for the different metal densities.

Deposition Rate in Production

The Wire Size Mistake

A structural shop bids a job with 800 lbs of weld metal using 0.035" wire at 4.5 lbs/hr deposition. Estimated arc time: 178 hours. At 30% arc-on factor, that's 593 shift hours — roughly 75 man-days. Midway through the job, the foreman realizes switching to 0.045" wire at the same WFS would bump deposition to 7.6 lbs/hr. The remaining 400 lbs would take only 53 arc hours instead of 89 — saving 120 shift hours ($7,200 in labor). The deposition calculator would have shown this 65% productivity gain before the job started, saving the shop thousands.

The Arc-On Factor Reality

An estimator calculates 40 hours of arc time for a pipe rack project. He tells the project manager "40 hours." The PM schedules one welder for 5 days. In reality, 40 hours of arc time at 25% arc-on factor (typical for pipe welding with heavy fit-up) means 160 actual shift hours — 20 man-days, not 5. Using the deposition calculator's arc-on time output and applying a realistic arc-on factor would have prevented the 3-week schedule overrun.

Deposition Rates by Wire Size (Steel Solid Wire, 95% Eff)

Wire Diameter	200 IPM	300 IPM	400 IPM	500 IPM
0.023"	1.3 lbs/hr	2.0	2.6	3.3
0.030"	2.2	3.4	4.5	5.6
0.035"	3.1	4.6	6.1	7.6
0.045"	5.0	7.6	10.1	12.6
1/16" (0.0625")	9.7	14.6	19.4	24.3

Values are theoretical deposition at 95% efficiency. Actual deposition varies with transfer mode (short circuit, globular, spray, pulse) and shielding gas composition.

Pro Tips for Maximizing Deposition

Do This

✓Use the largest wire diameter the joint can tolerate. On thick plate in flat/horizontal position, switching from 0.035" to 0.045" wire increases deposition by 65% at the same WFS. On 3/4" plate, this can cut welding labor by 40%. Only drop to smaller wire for thin material or out-of-position work where heat control is critical.
✓Maximize arc-on factor, not just deposition rate. A welder running 12 lbs/hr deposition but only 15% arc-on factor deposits 1.8 lbs per shift hour. A welder running 6 lbs/hr at 40% arc-on factor deposits 2.4 lbs per shift hour — 33% more production despite half the deposition rate. Fixture design and fit-up quality have more impact on throughput than wire speed.

Avoid This

✗Don't confuse arc-on time with shift time. The deposition calculator gives you arc-on hours — the time the trigger is actually pulled. A production welder is only welding 25-35% of the shift. To estimate real completion: divide arc-on time by 0.30 for typical structural work, 0.20 for pipe, or 0.40 for automated fixturing.
✗Don't use the steel constant for aluminum. The 13.1 constant is steel-specific (density 0.283 lbs/in³). Aluminum density is 0.098 lbs/in³, so the constant becomes 4.6. Using the steel formula for aluminum will overestimate deposition by nearly 3x, causing absurd wire purchase orders and schedule estimates.

Frequently Asked Questions

What wire feed speed should I use for 0.035" wire?

For 0.035" ER70S-6 solid wire on mild steel with C25 gas (75/25 Ar/CO2): short circuit transfer runs at 150-300 IPM (for thin material, 18-14 gauge). Spray transfer requires 350+ IPM and higher voltage (26V+), suitable for thicker plate in flat/horizontal position. Most structural shops run 250-350 IPM in short circuit and 350-500 IPM in spray. Set WFS first, then adjust voltage for a smooth arc sound.

Why does doubling wire diameter quadruple deposition rate?

Because wire cross-sectional area is proportional to the square of the diameter (A = π/4 × D²). Doubling D from 0.035" to 0.070" squares the area: 4x more metal per inch of wire fed. So even at the same wire feed speed, 4 times as much steel passes through the gun per minute. This is why the D² term dominates the deposition formula and why switching to larger wire is the single fastest way to increase production throughput.

How does flux-core wire deposition compare to solid wire?

Flux-core wire (FCAW) typically deposits at higher rates than solid MIG wire at the same diameter because FCAW runs higher currents. However, 14-20% of FCAW wire weight is flux that becomes slag (not deposited metal). So while 0.045" FCAW may run at 500+ IPM and melt 12+ lbs/hr of wire, the actual deposited metal is only 10-11 lbs/hr. Use 85% efficiency for FCAW in the formula instead of 95% for GMAW solid wire. Despite the lower efficiency percentage, FCAW wins on total deposited metal per hour due to the much higher feed speeds it can sustain.

What is a realistic arc-on factor for production welding?

Typical arc-on factors: Structural steel fabrication (good fixturing): 30-40%. Pipe welding (heavy fit-up, purging): 15-25%. Robotic welding: 60-85%. Field erection: 10-20%. Most estimators use 25-30% as a safe average for manual welding. A shop that tracks arc-on factor and actively works to reduce non-welding time (better fit-up, pre-staged materials, welding positioners) can increase throughput by 30-50% without changing any welding parameters.