Choosing a welding consumable starts with the metal you are joining and what the finished part needs to withstand. Whether you are using MIG wire or TIG filler rod, the filler needs to suit the parent metal and provide the strength, corrosion resistance or heat resistance the job requires. Getting that match right helps the weld perform as intended in service.
The tables below bring together common materials, examples of the MIG wires and TIG rods used with them, and typical diameters for different material thicknesses. Use them to narrow down the options, then check your choice against the actual alloy grade, joint, equipment and welding procedure. The fillers listed within each row serve different applications, and thickness alone does not determine the diameter.
Not Sure Which Consumable to Choose?
If you would like help narrowing down the options, our free online tools give you a starting point based on the material and thickness you are welding:
- 🔧 MIG Wire Finder Tool – explore MIG wire options for your material and thickness.
- 🔧 TIG Rod Finder Tool – find TIG filler rod options to suit the material and thickness of your job.
MIG Wires by Material
| Material | Recommended MIG Wires | Example Uses | Shop the Range |
|---|---|---|---|
| Carbon / Mild Steel | ER70S-6, ER70S-3, ER70S-2 | Structural frames, bridges, pipelines and general fabrication | Mild Steel (ER70S) |
| Low-Alloy Steel | ER80S-D2, ER80S-G, ER100S-1 | Heavy machinery, automotive components and construction work | High Strength Steel (ER80S+) |
| High-Strength Low-Alloy (HSLA) Steel | ER80S-D2, ER100S-1 | Aerospace, automotive and military equipment, with the filler selected for the steel grade | High Strength Steel (ER80S+) |
| Stainless Steel (austenitic & martensitic) | ER308L, ER309L, ER316L, ER347, ER410 | Food-processing equipment, medical instruments and chemical plant, depending on the stainless grade | Stainless Steel (ER3xx) |
| Duplex Stainless Steel | ER2209, ER2307, ER2594 | Chemical and petrochemical plant, oil and gas equipment, and marine fabrication | Duplex Stainless (ER2xxx) |
| Aluminium | ER4043 (silicon alloyed); ER5356 and ER5183 (magnesium alloyed) | Bodywork, boat fittings, structural aluminium and tanks, using a filler compatible with the alloy | Aluminium (ER4xxx/5xxx) |
| Nickel-Based Alloys | ERNiCrMo-3 (Inconel 625), ERNiCrMo-4 (Hastelloy C-276), ERNiCu-7 (Monel 400), ERNiFeCr-2 (Inconel 718) | Aerospace components, power-generation equipment and chemical plant | Specialty Alloy (ERNiCrMo) |
| Flux-Cored Steel | E71T-1 (gas-shielded); E71T-11 (self-shielded); E71T-GS (self-shielded, single-pass) | Fabrication and site work within the wire’s thickness and pass limits. Self-shielded types suit outdoor work; gas-shielded types need protection from wind. | Flux Cored Steel (E7xT) |
| Flux-Cored High-Strength Steel | E8xT-series wires, such as E81T1-Ni1; check the full product classification | Higher-strength structural steel, plant and machinery | Flux Cored High Strength (E8xT+) |
| Flux-Cored Stainless | E308LT-, E309LT- and E316LT-series wires; check the full classification and shielding gas | Stainless fabrication where the selected wire offers positional capability and a higher rate of weld-metal deposition | Flux Cored Stainless (3xxL-T) |
| MIG Brazing / Coated Sheet | CuSi3 (ERCuSi-A), CuAl8 (ERCuAl-A2) | Galvanised or zinc-coated sheet, car body panels and thin steel where the specified joining method is MIG brazing | Brazing (ERCu) |
| Wear Surfaces | Hardfacing wires, gas-shielded or open-arc | Restoring wear resistance on bucket edges, augers, wear plate, crusher parts and agricultural tools | Hard Facing |
| Tool Steel | ER312 or selected nickel-based wires for some repairs; other jobs need a filler designed for the tool steel | Repairing dies, moulds and cutting tools | Choose for the tool steel grade, required hardness and heat treatment |
| Cast Iron | ERNiFe-CI, ERNi-CI | Repairs to engine blocks, pump housings and machinery castings | MMA electrodes are also widely used for cast iron repairs; choose the process and filler to suit the casting |
TIG Rods by Material
| Material | Recommended TIG Rods | Example Uses | Shop the Range |
|---|---|---|---|
| Carbon / Mild Steel | ER70S-2, ER70S-6 | Pipework, general fabrication, thin sheet and the first pass at the root of a joint | Mild Steel (ER70S) |
| Low-Alloy Steel | ER80S-D2, ER90S-B3, ER110S-G | Heavy machinery, chrome-moly pipework and pressure equipment, using a filler suited to the specific steel | High Strength Steel (ER80S+) |
| High-Strength Low-Alloy (HSLA) Steel | ER100S-G, ER110S-G | Aerospace, motorsport and military equipment, with the filler selected for the steel grade | High Strength Steel (ER80S+) |
| Stainless Steel (austenitic & martensitic) | ER308L, ER309L, ER316L, ER347, ER410 | Food-processing equipment, medical instruments and chemical plant, depending on the stainless grade | Stainless Steel (ER3xx) |
| Duplex Stainless Steel | ER2209, ER2594 | Chemical and petrochemical plant, oil and gas equipment, and marine fabrication | Duplex Stainless (ER2xxx) |
| Aluminium | ER4043 (silicon alloyed); ER5356 (magnesium alloyed) | Bodywork, boat fittings, tanks and castings, using a filler compatible with the alloy | Aluminium (ER4xxx/5xxx) |
| Nickel-Based Alloys | ERNiCrMo-3, ERNiCr-3, ERNiCu-7 | Aerospace components, power-generation equipment and chemical plant | Specialty Alloy (ERNiCrMo) |
| Titanium | ERTi-2 (commercially pure), ERTi-5 (6Al-4V) | Aerospace, motorsport and chemical plant. Protect hot metal with suitable shielding, including trailing and back shielding where required. | Titanium (ERTi) |
| Magnesium | ERAZ61A, ERAZ92A | Castings, motorsport components and lightweight housings | Magnesium (ERAZ) |
| Dissimilar & Coated Metals | ERCuSi-A (silicon bronze), ERCuAl-A2 (aluminium bronze) | Brazing suitable combinations of steel and copper alloys, including some thin-sheet, coated-sheet and bicycle-frame work | Brazing (ERCu) |
| Wear Surfaces | Hardfacing TIG rods | Precisely rebuilding tooling, valve seats and small worn areas | Hard Facing |
| Tool Steel | ER312 or selected nickel-based fillers for some repairs; other jobs need a filler designed for the tool steel | Repairing dies, moulds and cutting tools | Choose for the tool steel grade, required hardness and heat treatment |
| Cast Iron | ERNi-CI, ERNiFe-CI | Repairs to engine blocks, pump housings and machinery castings | Choose the filler and repair procedure together, including any preheat and controlled cooling the casting needs |
Recommended Wire & Rod Diameter by Material Thickness
| Material Type | Material Thickness | Typical Wire Diameter (MIG) | Typical Rod Diameter (TIG) | Notes |
|---|---|---|---|---|
| Mild / Carbon Steel | < 1.5 mm (sheet) | 0.6 – 0.8 mm | 1.0 – 1.6 mm | Smaller diameters can help you work at lower currents; correct settings and travel speed are still needed to avoid burn-through. |
| 1.5 – 6 mm | 0.8 – 1.0 mm | 1.6 – 2.4 mm | Useful starting sizes for automotive work and general fabrication. | |
| 6 – 12 mm | 1.0 – 1.2 mm | 2.4 – 3.2 mm | Choose the current and joint preparation for adequate fusion; smaller filler may still suit individual passes. | |
| > 12 mm | 1.2 – 1.6 mm | 3.2 – 4.0 mm | Starting options for thick plate and structural work; diameter also depends on the joint and welding sequence. | |
| Stainless Steel | < 3 mm | 0.8 – 1.0 mm | 1.6 mm | Use a size that lets you control the weld pool, with suitable settings to limit heat input and distortion. |
| 3 – 6 mm | 1.0 – 1.2 mm | 2.4 mm | Typical starting sizes for stainless fabrication, including food and chemical plant equipment. | |
| > 6 mm | 1.2 – 1.6 mm | 3.2 mm | A TIG root followed by MIG filling is one option where the procedure allows it. | |
| Aluminium | < 3 mm | 0.8 – 1.0 mm | 1.6 mm | A compatible spool gun or push-pull torch can improve feeding, especially with small, soft aluminium wire. |
| 3 – 6 mm | 1.0 – 1.2 mm | 2.4 mm | Choose a diameter that feeds reliably and supplies filler at a suitable rate for the joint. | |
| > 6 mm | 1.2 – 1.6 mm | 3.2 – 4.0 mm | Starting options for heavy aluminium plate and structural work; confirm the size against the joint and procedure. | |
| Flux-Cored (Steel / Stainless) | 3 – 12 mm | 1.2 – 1.6 mm | Not applicable | Common fabrication sizes; smaller self-shielded steel wires are also available. Check the product’s thickness and pass limits. |
| Titanium / Magnesium | < 6 mm | TIG is more usual for the work covered here | 1.6 – 2.4 mm | Plan suitable gas shielding and cleaning alongside the filler choice. |
| Nickel Alloys / Exotics | Varies | 0.9 – 1.2 mm | 2.4 – 3.2 mm | Use the welding procedure and filler manufacturer’s data to confirm the size for the specific alloy and joint. |
Quick Rules of Thumb
- Thicker material often calls for more welding current and more filler, but the diameter also needs to suit the joint and each weld pass.
- Smaller diameters can make thin sheet easier to weld, particularly with MIG. Choose settings that control heat input as well, because wire or rod size alone will not prevent burn-through.
- Flux-cored wires come in a range of sizes. Although 1.2 mm and larger wires are common in fabrication, some self-shielded steel wires are available in 0.8 or 0.9 mm for lighter work.
- Check what your machine can run. Match the wire diameter to its supported range, available current and feeding equipment, including the drive rolls, liner and contact tip.
- Before ordering, check the filler manufacturer’s data sheet and any welding procedure specification for the job. Use them to confirm the filler classification, diameter and operating requirements for your application.
