E312-16 Dissimilar & Unknown Stainless Welding Rod
E312-16 Amperage by Diameter
| Diameter | Amperage Range |
|---|---|
| 3/32" (2.4 mm) | 40 - 80A |
| 1/8" (3.2 mm) | 75 - 125A |
| 5/32" (4 mm) | 110 - 165A |
E312-16 is a high-alloy stainless steel electrode under AWS A5.4 depositing approximately 29% chromium and 9% nickel. This chemistry produces a duplex microstructure with both austenite and ferrite phases. The high ferrite content (typically 25-50 FN) gives E312-16 exceptional resistance to hot cracking, making it the safest choice for welding unknown stainless steels, dissimilar stainless-to-stainless joints, and repair work where the base metal composition is uncertain. The -16 coating provides good AC and DCEP operation with smooth arc characteristics. E312-16 is widely used as a maintenance and repair electrode because it tolerates dilution from a wide range of base metals without cracking.
What This Means in Practice
E312-16 is the problem-solver rod for stainless welding. When you do not know what grade of stainless you are welding, or when you are joining dissimilar stainless grades to each other, E312-16 is the safest choice. Its 29Cr-9Ni chemistry produces a duplex (austenite + ferrite) microstructure that resists hot cracking better than any other common stainless electrode.
E312-16 Suitability Scores
How well this electrode matches common applications. Not a quality rating. all AWS-certified electrodes meet their specification.
When to Use E312-16
Use E312-16 when the stainless steel grade is unknown, when joining dissimilar stainless grades, or when previous attempts with other stainless electrodes have resulted in cracking.
Excellent for maintenance and repair work on stainless equipment where base metal analysis is impractical.
Also used for hard-to-weld stainless castings and for buffer layers on dissimilar joints.
E312-16 Limitations
Not appropriate for high-temperature service above 700F due to sigma phase embrittlement risk.
Not suitable for cryogenic service.
The weld deposit is not true austenitic stainless and has different corrosion properties than 308L or 316L.
More expensive than standard stainless electrodes.
Should not be used where specific corrosion resistance matching the base metal is required.
E312-16 Storage Requirements
Store sealed in dry conditions. Less moisture-sensitive than low-hydrogen carbon steel rods.
E312-16 Technical Specifications
| Property | Value |
|---|---|
| AWS Classification | E312-16 |
| Process | stainless-electrodes () |
| Polarity | AC, DCEP |
| Positions | flat, horizontal, vertical up, overhead |
| Penetration | medium |
| Coating Type | rutile (titania) |
| Tensile Strength | 95,000 psi |
| Yield Strength | 72,000 psi |
| Elongation | 22% |
| Base Metals | Unknown stainless steels, Dissimilar stainless joints, 300-series stainless, 400-series stainless, Stainless castings |
| AWS Specification | A5.4 |
Frequently Asked Questions
When should I use E312-16 instead of E308L-16?
Use E312-16 when you do not know the exact grade of stainless you are welding, when joining two different stainless grades together, or when previous welds with E308L-16 or E309L-16 have cracked. E312-16 has the highest ferrite content of common stainless electrodes, giving it the best hot-cracking resistance. It is the go-to problem-solver rod for difficult stainless repairs.
Can E312-16 be used at high temperatures?
No. E312-16 is not suitable for service temperatures above approximately 700F (370C). At higher temperatures, the high ferrite content can transform into sigma phase, causing severe embrittlement. For high-temperature stainless applications, use E310-16 instead.
Why is E312-16 called a maintenance rod?
E312-16 tolerates dilution from a wide range of stainless and carbon steel base metals without cracking. In maintenance and repair work, you often encounter unknown alloys, contaminated surfaces, or dissimilar metal joints. E312-16 handles all of these situations better than any other single stainless electrode, which is why repair shops and maintenance crews keep it on hand.
External Resources
Manufacturer data sheets and standards for E312-16.
Data sourced from AWS A5.4/A5.4M. Amperage ranges are approximate starting points. adjust based on position, fit-up, and material thickness. Always follow manufacturer recommendations and applicable codes.