# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DbeWkwSvhop
- **Gondola URL:** https://gondola.cc/posts/68532551-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/d906c62c7e.jpg
- **Posted:** 2026-07-31T22:39:13.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

A machine that cuts hardened steel without ever touching it.

Electrical discharge machining removes metal with controlled lightning. The workpiece and a shaped electrode sit submerged in dielectric fluid, separated by a gap of roughly 10 to 100 micrometres. A pulse generator raises the voltage until the dielectric breaks down. A plasma channel forms, reaching temperatures above 8,000 degrees Celsius. The metal does not shear. It melts and vaporises.

Then the voltage collapses. The plasma implodes, dielectric floods back into the gap, and the molten pool is flushed away as microscopic debris. What remains is a crater a few micrometres across. Repeat tens of thousands of times per second and you have a machining process.

The consequences are strange.

- Hardness is irrelevant. Tungsten carbide, hardened tool steel and Inconel erode at similar rates to mild steel, because removal depends on melting point and thermal conductivity, not mechanical strength.
- Cutting forces are effectively zero. Wall sections thinner than 0.1 mm survive intact.
- Internal square corners become possible. No rotating tool means no corner radius.
- The workpiece must conduct electricity. Ceramics and polymers are excluded unless doped.

Two dominant variants exist. Sinker EDM plunges a graphite or copper electrode shaped as the negative of the desired cavity, the standard route for injection mould tooling. Wire EDM feeds a continuously spooling brass wire, typically 0.25 mm in diameter, through the part like a bandsaw blade made of sparks.

The trade-off is speed. Removal rates sit far below conventional milling, and every discharge leaves a recast layer of resolidified metal carrying tensile residual stress and micro-cracks. Aerospace and medical components usually demand that layer be polished or etched away.

Precision is not always about force. Sometimes it is about restraint.

#stemantics #edm #manufacturing #engineering #machining

## Stats

- **Views:** 9,445
- **Likes:** 191
- **Shares:** 0
- **Comments:** 1

## Tags

machining, engineering, edm, manufacturing, stemantics

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