How to Identify Inconel vs. Stainless Steel Before You Sell
"I have a bunch of pipe fittings and flanges from a plant teardown. Some of them look like stainless but they're marked differently. How do I know if any of it is Inconel?"
The fastest field test: use a magnet. Inconel 625 and 718 are non-magnetic. Most 304/316 stainless is also non-magnetic, but 400-series stainless IS magnetic. The definitive test is XRF (X-ray fluorescence) — we do this for free. The stakes are high: Inconel pays $8–$14/lb vs. stainless at $0.45–$0.80/lb.
Inconel and stainless steel look nearly identical to the naked eye. But the price difference is enormous — Inconel 625 pays $10–$14/lb while 304 stainless pays $0.50–$0.70/lb. Misidentifying your material can cost you thousands of dollars on a single load. Here's how to tell them apart.
The Magnet Test — First Step
Grab a strong rare-earth magnet. Press it firmly against the metal. Inconel 625, 718, and most other nickel alloys are non-magnetic — the magnet will not stick. 304 and 316 stainless are also non-magnetic. 400-series stainless (430, 410) IS magnetic. So if the magnet sticks, it's almost certainly 400-series stainless, not Inconel. If the magnet doesn't stick, you need the next test.
Markings and Stamps to Look For
Inconel parts from industrial applications are often stamped or etched with the alloy designation. Look for: 625, 718, IN625, IN718, UNS N06625, UNS N07718, or the manufacturer's heat number. Stainless will be marked 304, 316, SS304, 18-8, or similar. Pipe fittings often have the material stamped on the fitting body or on a tag wired to the part.
Color and Surface Differences
Fresh-cut Inconel has a slightly more golden or yellowish tint compared to the bright silver of stainless. Inconel also tends to work-harden more aggressively — if the parts have been machined, the cutting marks will look different. However, these visual differences are subtle and unreliable without experience. Don't rely on color alone.
XRF Testing — The Only Definitive Answer
X-ray fluorescence (XRF) testing reads the exact elemental composition of the metal in seconds. It will tell you precisely whether you have Inconel 625 (58% nickel, 21% chromium, 9% molybdenum) or 316 stainless (16% chromium, 10% nickel, 2% molybdenum). ScrapMetalBuyers.com provides free XRF testing on unidentified alloys. Bring your material in or schedule a pickup and we'll test it on the spot.
Frequently Asked Questions
What is the price difference between Inconel and stainless?
Inconel 625 pays $10–$14/lb. Inconel 718 pays $8–$12/lb. 304 stainless pays $0.50–$0.70/lb. 316 stainless pays $0.60–$0.85/lb. On 100 lbs, that's a $950–$1,350 difference.
Can I tell Inconel from stainless with a magnet?
A magnet test is a useful first step but not definitive. Both Inconel and 300-series stainless are non-magnetic. Only XRF testing gives a definitive identification.
Do you do free XRF testing?
Yes. We test all unidentified alloys for free. Call (754) 310-2984 or bring your material to us.
What industries generate Inconel scrap?
Oil and gas (wellhead components, tubing), aerospace (turbine blades, exhaust systems), chemical processing (reactor vessels, heat exchangers), and power generation (boiler components).