Welding and Metal Fab

Weld Deposition Rate: What It Is and How to Estimate It

Weld deposition rate is the mass of filler metal deposited per hour of arc-on time. Here is how to calculate it and use it to estimate wire consumption and arc time per joint.

Weld deposition rate in kg per hour equals wire feed speed in meters per minute x wire cross-section area x wire density x 60. For 1.2 mm ER70S-6 MIG wire at 8 m/min, the wire area is pi x (0.0006)^2 = 1.13 x 10^-6 m^2, and with steel density of 7850 kg/m^3 the gross deposition rate is about 4.26 kg/hr. At 95% efficiency, net deposited rate is about 4.05 kg/hr. This is the base calculation behind wire usage and arc-time estimates in fabrication quotes. If the deposition rate is wrong, every downstream welding cost number will be wrong too.

Deposition rate depends mainly on wire feed speed, wire diameter, density, process type, and deposition efficiency. Typical benchmarks are about 1.5 to 3.0 kg/hr for short-circuit MIG, 5 to 9 kg/hr for spray transfer MIG, 6 to 12 kg/hr for flux-core in flat position, and 10 to 25 plus kg/hr for submerged arc welding. Joint volume tells you how much weld metal is actually needed, and that volume should come from weld size, joint prep, and weld length. For example, a 6 mm fillet with a 300 mm length has about 42.4 grams of deposited weld metal. At 3 kg/hr, that joint needs about 50.9 seconds of arc-on time.

The most common mistake is assuming wire feed speed equals deposited metal with no losses. Spatter, burn-off variation, and process instability reduce effective deposition, especially on dirty material or poor parameter setups. Another common miss is using a benchmark from flat-position welding on a job that must be welded vertical or overhead. Shops also fail to check contact tip wear and power source calibration, even though both can pull actual wire feed down by 10% to 15%. That gap directly reduces real deposition and increases labor cost per joint.

Use deposition rate to estimate wire consumption and labor for each weldment. If a joint needs 0.5 kg of deposited weld metal and your net deposition rate is 4 kg/hr, arc time is 0.5 / 4 = 0.125 hours, or 7.5 minutes. That lets you compare processes, joint designs, and automation options on a common basis. If measured deposition is well below the expected rate for the chosen process, investigate wire feed consistency, liner condition, contact tips, and travel technique before blaming the welder. This turns deposition rate from a textbook value into a production control number.

Higher deposition rate can reduce labor cost, but it can also raise heat input and distortion. Thin-gauge assemblies, pressure parts, and code-governed welds may not tolerate the highest-output settings. Related checks such as heat input, interpass temperature, and procedure qualification records have to stay in bounds when you push deposition up. Pair deposition rate with weld repair rate and actual arc-on percentage to see whether the faster setting really helps the job. A good deposition target is one that shortens labor without creating new quality problems downstream.

Published 2026-05-28.