Under the Microscope

Part 2: Electron Microscopy

We put OUR grinder
inside an electron microscope.

In Part 1, a handheld XRF analyzer identified the tested material in our OG1 grinder as SS-304. Then SEM-EDS, a different machine using an electron beam, examined the surface and elemental composition of the tested metal. Here's our report.

Photo: OG1's base, taped to the SEM sample stage during testing.

Specular OG1 grinder inside the open chamber of the scanning electron microscope — Inside the SEM chamber, ready for vacuum.

The Specular logo, engraved into the metal being tested.

Scanning electron microscope used for the SEM-EDS analysis — Scanning electron microscope + EDS detector.

What an SEM-EDS test is

In an SEM-EDS test, a scanning electron microscope images the surface with an electron beam, then an EDS detector reads the X-rays the material emits back. This microscopic scan gives a localized elemental view of the exact areas examined, at magnifications far beyond ordinary photography. It's a standard tool in materials labs for failure analysis and quality work.

Why it matters

One instrument's identification is good. A second, genuinely different analytical method examining OG1 stainless steel surfaces is better. The XRF identification in Part 1 carries the SS-304 claim; the SEM-EDS is the supporting witness. And you can see our engraved mark at 40x and the machined stainless steel surfaces at 250 to 500x magnification.

The "S" under the beam

This is the "S" from the SPECULAR logo engraving on the bottom of the grinder, imaged at 40x by the electron microscope. The instrument's data bar is taken directly from the testing equipment: 40x magnification, 500 µm scale, secondary-electron detector, dated the day of the test.

Our logo isn't printed on. It's engraved into the steel, so the SEM image reveals the actual topography of the letter "S" with the surrounding machined surface visible around it. Every OG1 carries this mark, and a mark on metal should mean something: if we put our name in the steel, we can vouch for its quality and authenticity.

Scanning electron microscope image at 40x magnification of the letter S from the SPECULAR engraving on the OG1 base — **40X · THE SIGNATURE**The engraved "S" under the electron beam.

The magnified surface

SEM micrograph of the Specular OG1 surface at 250x magnification with EDS elemental analysis — **250X · THE EDGE**The machined surface imaged directly at the edge.

SEM micrograph of the Specular OG1 top surface at 500x magnification with EDS elemental analysis — **500X · TOP SURFACE**The visible line patterns are consistent with the machining operations used to produce the OG1; the kind of surface detail only an electron microscope shows.

SEM micrograph of the Specular OG1 bottom surface at 500x magnification with EDS elemental analysis — **500X · BOTTOM SURFACE**The circular patterns are consistent with the facing operations. The same principal alloying elements (iron, chromium, nickel, manganese) were detected across all three analyzed areas.

SEM-EDS ELEMENTAL ANALYSIS SPECULAR OG1 · SURFACE SCANS

SUPPORTING ANALYSIS: CHROMIUM-NICKEL STAINLESS Grade identification comes from the XRF instrument (Part 1). EDS readings in the areas tested were consistent with a chromium-nickel stainless composition.

Element	EDS finding	What it means
Fe (Iron)	Base metal	The primary base metal in stainless steel.
Cr (Chromium)	Detected	Present at stainless levels, consistent across all tested areas.
Ni (Nickel)	Detected	Present on every scan: a chromium-nickel composition.
Mn (Manganese)	Low	The measurements do not show the high-manganese, lower-nickel pattern typical of Type 201.
Si (Silicon)	Trace	Normal trace constituent of stainless steel.
C (Carbon)	4 to 6% (surface)	Reported on every spectrum. Surface carbon on an unprepared sample is common in SEM-EDS and is not the bulk carbon content of the steel; see the fine print below.
S (Sulfur)	0.12% (one area)	Reported in one of the three spectra and not in the other two. Surface EDS is not used to certify bulk sulfur.

VIEW FULL SEM-EDS RESULTS (PDF) →

Reading the fine print

EDS is a localized, semiquantitative surface analysis, so its reported percentages should not be interpreted as a mill chemistry certification. This is why the grade identification on this page comes from the XRF instrument and the full EDS numbers live in the downloadable report rather than the headline. Carbon reported by EDS on an unprepared surface can be strongly influenced by surface and electron-microscope contamination, so those carbon readings should not be interpreted as the bulk carbon content of the steel. Because each spectrum is normalized to 100%, surface carbon can contribute to lower displayed chromium and nickel percentages than the XRF values in Part 1. EDS and XRF are different methods, which is another reason the EDS percentages should not be compared directly with bulk specification limits. A small sulfur signal was observed in one EDS spectrum, and in one XRF reading in Part 1; a properly prepared laboratory bulk chemistry analysis, such as spark OES, would be appropriate for determining the minor elements that handheld XRF and surface EDS do not fully establish. The reports can be difficult to interpret, but we publish them in full to raise the bar on marketing claims vs. test results.

XRF-identified SS-304, examined at 500x

The OG1 is machined from the stainless steel you just saw at a micron level: identified as SS-304 by XRF in Part 1, examined here by SEM-EDS.

See the OG1 Part 1: XRF Identification