EDM & Wire EDM Machining Services

What we machine on this process

Wire EDM and sinker (die-sinking) EDM both remove metal by electrical discharge rather than by cutting pressure, which lets them reach features a rotating cutter cannot. Wire EDM runs a thin, continuously-fed wire through the workpiece to cut a precise through-profile; sinker EDM lowers a shaped electrode into the workpiece to burn a blind cavity. On this process we typically machine die and mould inserts, punch and die components, internal splines and keyways, narrow slots, sharp internal corners, and profiles cut directly from already-hardened stock. Because the process applies no mechanical cutting force, it holds thin walls and slender features without deflecting them. Send your drawing and we will tell you whether EDM alone, or a milling pass first, is the right route.

Materials and finishes

EDM works on any conductive metal, so the material list is broad. We commonly run aluminium 2024, 5052, 6061 and 7075; stainless steel 301, 303, 304, 316 and 17-4PH; carbon and alloy steel 1045, 1215, 4140, D2 and O1; brass, copper and bronze; and titanium. Hardened tool steel is a common EDM case because the process cuts it after heat treatment, when milling would struggle. See the full grade list on our materials page. After EDM, surfaces can be finished the same way as milled parts — anodizing for aluminium, passivation for stainless steel, and plating or polishing for steels — all arranged through our vetted partner network, managed under one quality process. Tell us the end use and we will recommend a finish that suits the material.

Size, tolerance and capacity limits

EDM capacity is arranged through our vetted partner network, managed under one quality process, and quoted from your drawing rather than from a fixed machine list. We do not quote from a machine count; each job is evaluated per drawing for wire diameter, part thickness, slot depth and corner requirements. Precision features are held to ±0.01 mm and general tolerances follow ISO 2768-m unless stated on the drawing. Wire EDM suits deep, narrow slots and stack-cut profiles, while sinker EDM reaches blind cavities a cutter cannot enter. The practical limits — maximum workpiece thickness, minimum internal corner radius and achievable surface finish — are confirmed in the quote rather than guessed. Our tolerances page explains the tolerance framework we quote against.

Documents and shipping

EDM work is quoted and managed from our own factory in Qidong City, Jiangsu Province, China, with the EDM step run through our vetted partner network under the same process we apply to everything we ship. Every batch leaves with a material certificate (MTR) and pre-shipment photos of your actual parts, so you can confirm the grade and finish before the box is dispatched. There is no extra paperwork you did not ask for. Drawing review, programming, scheduling and dispatch stay on our side, which keeps one contact responsible from first quote to delivery.

Industries we support

EDM parts feed the same industries as our CNC machining work. Die and mould inserts serve production tooling; hardened profiles and small, deep slots appear in automotive, medical and electronics hardware; and erosion-resistant features show up in oil and gas and aerospace components. Because EDM is often a finishing step after milling or turning, we can combine processes on one order so a part arrives complete rather than needing a second supplier. Browse our industries hub to see how each sector uses precision-machined parts.

Design guidelines for cost and manufacturability

A few design rules keep EDM economical. Wire EDM cuts a slot or profile slightly wider than the wire plus a spark gap, so design internal corners to a realistic radius rather than a true sharp corner; a sharp internal corner is where sinker EDM with a shaped electrode becomes necessary, and it costs more. Keep slot depth realistic for the wire diameter, and remember wire EDM needs a start hole or an open edge to thread the wire. On surface finish, EDM leaves a recast layer — a thin heat-affected skin — so specify the finish you need and allow for a light post-process where it matters. Thin walls and slender features are actually a strength of EDM because there is no cutting force. Our drawing requirements page lists what to include so the first quote is accurate.