--- title: "EDM & Wire EDM Services | Hard Metals, Fine Detail | OpenSpindle" description: "Get quotes for wire, sinker, and small-hole EDM from independent machine shops. Spark erosion cuts hardened and exotic metals with no cutting force. Upload a drawing." canonical: https://openspindle.com/capabilities/edm --- # EDM and wire EDM from independent machine shops Spark erosion removes conductive metal with no cutting force, so it cuts hardened tool steel, carbide, and exotic alloys and holds fine, intricate detail milling cannot. Upload a drawing and hear back from shops set up for EDM. ## EDM shops on OpenSpindle Real shops that cut hardened and exotic parts by spark erosion. See their equipment and talk to the person making your part. [Browse all EDM shops](https://openspindle.com/manufacturers?capability=EDM) ## Conductive metals our EDM shops cut EDM works on any electrically conductive metal regardless of hardness. Common alloys are below; if yours is not here, ask when you request a quote. - [Carbon & tool steel](https://openspindle.com/materials/carbon-steel.md) -- D2 · A2 · hardened - [Stainless steel](https://openspindle.com/materials/stainless-steel.md) -- 304 · 316 · 17-4 - [Titanium](https://openspindle.com/materials/titanium.md) -- Grade 5 - [Copper](https://openspindle.com/materials/copper.md) -- C110 - [Brass](https://openspindle.com/materials/brass.md) -- C360 - [Aluminum](https://openspindle.com/materials/aluminum.md) -- 6061 · 7075 ## Tolerances | Feature | With drawing | No callout | | --- | --- | --- | | Wire EDM profile | ±0.0002 in | ISO 2768 Fine | | True position | ±0.0005 in | ISO 2768 Fine | | Sinker cavity depth | ±0.001 in | ISO 2768 Medium | | Surface finish | 8-32 Ra | 32 Ra as-cut | Wire EDM is one of the most precise cutting processes; profiles commonly hold ±0.0002 in. Finer finishes need extra skim passes that add time. Call out the critical dimension and shops confirm before cutting. ## Threads, Inserts & Finishing Tapped holes, dowel pins, and pressed inserts are added as secondary ops. EDM itself makes the precise bore, slot, or keyway; a mill or grinder handles conventional features. Applied after cutting. As-cut ships fastest; passivation and plating are common on EDM steel and stainless parts, and the recast layer can be polished or stress-relieved where needed. | Finish | Materials | Adds | Stacks with | | --- | --- | --- | --- | | As-cut | All | +0 days | Anything | | Recast layer removal | Tool steel, carbide | +1-2 days | Polish | | Passivation | Stainless only | +2 days | Bead blast | | Zinc / nickel plating | Steel | +3-5 days | Passivation not needed | EDM leaves a thin recast (white) layer. For fatigue-critical or mold parts, ask for it to be polished or ground off so the shop plans that pass. ## What Makes a Good RFQ | Instead of | Send | | --- | --- | | "EDM part, need a quote" | "D2 tool steel, hardened 60 HRC, wire EDM profile per drawing, qty 25" | | "Sharp corners inside" | "0.006 in internal corner radius, wire EDM, ±0.0005 on the slot width" | | "Small hole in a hard part" | "⌀0.020 in hole, 0.75 in deep, small-hole EDM through carbide" | Say the material hardness, the tightest feature, and its tolerance. Hardness is why EDM was chosen and it sets the price. ## Industries Served - Aerospace - Defense - Medical devices - Mold & die - Tool & die - Automotive - Firearms - Industrial / OEM EDM shops on OpenSpindle cut dies, molds, hardened tooling, and precision components for demanding industries, including AS9100 and ITAR-registered shops. ## Frequently Asked Questions ### What is the difference between wire EDM and sinker EDM? Wire EDM feeds a thin electrically charged wire through the part to cut a 2D or tapered profile through the full thickness, ideal for tight internal corners, thin webs, and precise slots. Sinker (ram) EDM burns a shaped electrode down into the part to make a blind cavity, sharp internal corner, or keyway. Many shops offer both and pick from your drawing. ### Why use EDM instead of milling? EDM removes metal with electrical sparks, not a cutting tool, so it applies no mechanical force to the part. That lets it cut fully hardened steel and carbide without distortion, produce corners far sharper than an end mill radius, and machine thin or delicate features that would deflect under a tool. ### What materials can be cut by EDM? Any electrically conductive material, regardless of hardness: hardened tool steel like D2 and A2, carbide, Inconel, titanium, copper, and stainless. Non-conductive materials such as plastics, ceramics, and composites cannot be EDM cut. ### How tight are the tolerances? Wire EDM commonly holds ±0.0002 in on a profile with fine surface finishes. Tighter finishes come from additional skim passes. Call out the one critical dimension and the shop confirms before cutting. ### What is small-hole or hole-popping EDM? A fast-drilling EDM process that burns small, deep, precise holes using a rotating tubular electrode, even in hardened material. It is common for cooling holes, starter holes for wire threading, and holes with high depth-to-diameter ratios. ### Is there a minimum order? No. Shops cut single prototypes and production runs. Expect a setup and programming charge on one-offs that drops on repeat orders. ### What file formats should I send? STEP, IGES, X_T, DWG, DXF, or a dimensioned PDF. Include material and hardness, the critical feature and its tolerance, thickness, quantity, and any finish. ## Other Capabilities - [CNC Machining](https://openspindle.com/capabilities/cnc-machining.md) - [5-Axis Machining](https://openspindle.com/capabilities/5-axis-machining.md) - [Swiss Machining](https://openspindle.com/capabilities/swiss-machining.md) - [Surface Grinding](https://openspindle.com/manufacturers?capability=Surface%20grinding) - [Waterjet Cutting](https://openspindle.com/capabilities/waterjet-cutting.md) - [Laser Cutting](https://openspindle.com/capabilities/laser-cutting.md) ## Design Notes That Move Your Price Not a definition of EDM. The design choices that move your price and lead time. - **Internal corner radius sets the wire:** A wire EDM corner is only as sharp as the wire radius, commonly 0.004 in and up. Call out a realistic internal radius; asking for a true sharp corner forces a slower, finer wire. - **Thickness drives cut time:** Wire EDM cuts the full stack height in one pass, so a taller part takes proportionally longer. Cutting a stack of thin parts at once is cheaper than one at a time. - **Skim passes buy finish, not shape:** Each extra skim pass tightens tolerance and smooths the surface but adds time. Only spec a fine finish where the part needs it. - **Give a start hole on closed profiles:** A closed internal cutout needs a threading hole for the wire. Adding a small pre-drilled hole, or letting the shop pop one, avoids a surprise op on hardened stock. ## Get EDM quotes Upload a drawing once and compare quotes from independent EDM shops.