ER312 Welding Wire
ER312 welding wire is a high-chromium stainless steel filler metal classified under AWS A5.9 and used for dissimilar-metal joints, difficult-to-weld steels, and stainless steel repair applications. With a nominal 29% chromium and 9% nickel composition, ER312 produces a ferrite-containing weld deposit with good resistance to weld-metal cracking. Metracore manufactures and supplies ER312 welding wire as COREWELD 312, available as ER312 MIG wire and TIG rod for fabrication and repair applications. Product dimensions, packaging, and certification are confirmed against the applicable product datasheet.
The COREWELD 312 datasheet sets out technical specifications, chemical composition, mechanical properties, and available sizes for ER312 welding wire.
What is ER312 Welding Wire?
A high-alloy stainless chemistry carrying 28.0-32.0% chromium against only 8.0-10.5% nickel defines ER312, the AWS A5.9 classification for this filler metal. Its chromium-rich, nickel-moderate chemistry produces a ferrite-containing weld deposit with good resistance to weld-metal cracking. This makes ER312 useful for dissimilar-metal joints, difficult-to-weld steels, and repair applications where crack resistance is an important consideration. It serves stainless fabrication and certain cladding or buffer-layer applications. Whether it suits a given joint still depends on the base-metal combination, the welding procedure, and the service conditions the finished weld will see.
Benefits of COREWELD 312 Filler Metal
Technical Specifications of COREWELD 312
COREWELD 312 ER312 welding wire is supplied to the AWS A5.9 ER312 classification and is available as continuous MIG wire or ER312 filler rod, subject to product form and size.
| Specification Parameter | Value / Detail |
| Brand | COREWELD 312 |
| Product Name | ER312 Welding Wire |
| AWS Classification | ER312 |
| Material Type | Stainless Steel Filler Metal |
| Welding Processes | MIG (GMAW) / TIG (GTAW) / SAW (Submerged Arc) |
| Applicable Standard | AWS A5.9 / ASME SFA-5.9 |
| Available Wire Diameters | 0.030 in (0.80 mm), 0.035 in (0.90 mm), 0.045 in (1.20 mm), 1/16 in (1.60 mm), 3/32 in (2.40 mm), 1/8 in (3.20 mm), 5/32 in (4.00 mm), 3/16 in (4.80 mm) |
| Rod Lengths | Supplied as cut lengths for GTAW |
| Packaging | Continuous spools for GMAW, cut lengths for GTAW |
| Base Material Compatibility | Cast alloys of similar composition, dissimilar metals, carbon steel to stainless steel, and weld overlays |
Chemical Composition of ER312 Filler Rod
| Element | Composition |
| Carbon (C) | 0.15% max (0.11% typical) |
| Chromium (Cr) | 28.0–32.0% (29.00% typical) |
| Nickel (Ni) | 8.0–10.5% (9.25% typical) |
| Manganese (Mn) | 1.0–2.5% (1.60% typical) |
| Silicon (Si) | 0.30–0.65% (0.40% typical) |
| Molybdenum (Mo) | 0.75% max (0.15% typical) |
| Phosphorus (P) | 0.03% max (0.013% typical) |
| Sulfur (S) | 0.03% max (0.013% typical) |
Mechanical Properties of ER312 Welding Rod
| Property | Value |
| Tensile Strength | 105,000 psi |
| Yield Strength | 75,000 psi |
| Elongation | 25% |
| Ferrite Content | High ferrite deposit |
| Hardness | Include only if specified |
Equivalent Grades of ER312 TIG Rod
| Standard | Designation |
| AWS / ASME | ER312 (AWS A5.9 / SFA-5.9) |
| Related Wrought Reference | Type 312 stainless (no single matched base metal) |
Applications of ER312 Welding Wire
The following are different applications of ER312 Welding Wire across the industries.
- Dissimilar-metal joints between carbon steel and stainless steel
- Buffer or underlay layers before hardfacing deposits
- Repair welding on stainless components of uncertain or mixed composition
- Cladding work requiring a crack-resistant, high-ferrite deposit
- Maintenance welding in fabrication shops handling mixed material stock
- Joining stainless to mild steel in structural repair work
Manufacturing Process of ER312 Welding Rod
Hot extrusion of the alloyed billet shapes ER312 rod ahead of finish drawing.
- Alloying to the target high-chromium, moderate-nickel composition
- Hot extrusion of the billet into rod stock
- Cold drawing through successive dies to finished diameter
- Straightening, cutting, and coiling or cut-length packing
- Dimensional and chemistry checks against AWS A5.9
Why Choose COREWELD 312 Welding Wire?
COREWELD 312 carries a verified AWS A5.9 classification rather than an unspecified stainless filler, with wire diameters, rod sizes, and packaging confirmed on the official datasheet. Technical support covers questions on base-metal pairing ahead of an order. Review the datasheet before selecting this filler metal for a dissimilar-metal or repair application. No claims are made regarding certifications or manufacturing capabilities beyond what is documented.
ER312 Welding Wire Supply and Technical Support
Technical procurement of ER312 welding wire entails validating specific base-metal combinations to determine the proper MIG wire diameters, TIG rod sizes, packaging configurations, and bulk supply requirements. Inquiries must state the base-metal grades to be combined, the specified welding procedure, and the required dimensional profiles to ensure engineering correctness and accelerate processing. As soon as current stock status, regional freight delivery schedules, and global export logistics coverage are verified, the technical appraisal of these project parameters will be finalized and provided to the client.
Products
FAQ's
What is ER312 Welding Wire used for?
It joins dissimilar metals and repairs stainless components where cracking resistance matters more than matched corrosion performance.
What is the difference between ER312 TIG Rod and MIG Wire?
ER312 TIG rod is supplied as cut lengths for GTAW and added manually to the weld pool, while ER312 MIG wire is supplied continuously through the welding gun for GMAW. The product form depends on the welding process and applicable procedure.
Which metals can be welded using ER312 Filler Metal?
Carbon steel to stainless steel joints and mixed-composition stainless repairs are the primary use, subject to the procedure specification.
What is the chemical composition of ER312 Welding Wire?
ER312 carries 28.0-32.0% chromium and 8.0-10.5% nickel under AWS A5.9, with the full range set out in the table above.
What sizes are available for COREWELD 312?
Confirm wire diameters, rod sizes, and packaging from the current datasheet.
Which standard applies to ER312 Welding Wire?
AWS A5.9 / ASME SFA-5.9, subject to certification on the product datasheet.