Electrical Discharge Machining (EDM) and Lab

Course Description

Electrical Discharge Machining (EDM) and Lab provides students with the ability to set up and operate wire-EDM and sinker-EDM machine technology found in the field of machining.

Within the SCNS taxonomy, PMT is the Precision Metals prefix, and the 0000-level number marks this as PSAV clock-hour instruction. Daytona State publishes it at 130 clock hours with a $76.55 lab fee, offered fall and spring, with PMT0202C, PMT0251C and PMT0260C as prerequisites — the most heavily gated course in the machining certificate. ⚠ It carries no college credit.

EDM removes metal by controlled electrical erosion rather than by cutting, which makes it capable of things no cutting tool can do: internal sharp corners, very hard materials, extremely thin features, and shapes with no tool access — and it exerts almost no force on the workpiece, so delicate parts do not deflect. That is why it is the technology behind most injection moulds and dies, and why EDM competence is a genuinely differentiating skill in a machinist's portfolio.

Learning Outcomes

Required Outcomes

• Describe the principle of electrical discharge machining.
• Describe the spark erosion process and material removal mechanism.
• Distinguish wire EDM and sinker (ram) EDM and their applications.
• Describe the role of the dielectric fluid and its maintenance.
• Describe flushing and its effect on cutting performance.
• Apply EDM-specific safety practice, including electrical and fluid hazards.
• Describe materials suitable for EDM and the requirement for conductivity.
• Set up a wire EDM machine, including threading and alignment.
• Select wire type and diameter for an application.
• Establish workpiece datums and alignment on the machine.
• Program wire EDM paths, including multiple passes.
• Apply offsets to achieve required dimensions and finishes.
• Describe taper cutting and its programming.
• Cut a part to dimension on wire EDM and inspect it.
• Set up a sinker EDM machine and align an electrode.
• Describe electrode materials and their selection.
• Design and produce electrodes for a required cavity.
• Apply orbiting and multiple electrode strategies.
• Select and apply appropriate power settings and parameters.
• Describe the recast layer and heat-affected zone and their implications.
• Balance speed, finish, and accuracy through parameter selection.
• Diagnose common EDM faults, including wire breakage and poor flushing.
• Perform routine machine maintenance including filters and resin.
• Produce a finished EDM part to drawing and inspect it.

Optional Outcomes

• Describe small-hole and fast-hole EDM.
• Describe EDM in mould and die making.
• Describe automation and unattended EDM operation.
• Describe surface finish specification in EDM.
• Describe cost and cycle time estimation for EDM.
• Describe combining EDM with conventional machining in a process plan.

Major Topics

Required Topics

• The EDM principle
• Spark erosion and material removal
• Wire versus sinker EDM
• Dielectric fluid and maintenance
• Flushing
• EDM safety
• Materials and conductivity
• Wire EDM setup and threading
• Wire selection
• Datums and alignment
• Wire path programming
• Offsets for dimension and finish
• Taper cutting
• Producing and inspecting a wire-cut part
• Sinker setup and electrode alignment
• Electrode materials
• Electrode design and production
• Orbiting and multiple electrodes
• Power settings and parameters
• Recast layer and heat-affected zone
• Balancing speed, finish, and accuracy
• Fault diagnosis
• Machine maintenance
• Producing a finished EDM part

Optional Topics

• Small-hole and fast-hole EDM
• Mould and die applications
• Automation and unattended operation
• Surface finish specification
• Cost and cycle time estimation
• Combining EDM with conventional machining

Resources & Tools

• The programme's shop, machines, and open lab hours — the reason to take this in person, and the single highest-return resource here. These are motor skills; hours on the machine are what build them.
• American Welding Society (aws.org) — codes, certification information, and student membership; the authority for anything in this guide about welder qualification.
• NIMS (nims-skills.org) — free credential standards and performance test specifications; read the standard before you sit the test.
• Machinery's Handbook — the machinist's reference, and worth owning even at its price; speeds, feeds, threads, tolerances, and materials.
• Welding Principles and Applications (Jeffus) — the standard welding text.
• Technology of Machine Tools (Krar) and Machine Shop Practice — the standard machining references.
• GD&T references based on ASME Y14.5 — geometric dimensioning and tolerancing is the language of engineering drawings and it is examinable.
• Manufacturer machine and control manuals — Haas, Fanuc, Mazak and others publish extensive free operator and programming documentation.
• Fusion 360 or Mastercam — Fusion 360 has free personal and educational licensing and is widely used for CAD/CAM; practise toolpaths outside lab hours.
• OSHA machine guarding and welding standards (osha.gov) — free, and directly relevant to the safety content of every course here.
• Your own measuring tools — a decent micrometer, calipers, and a dial indicator. Cheap measuring tools produce confident wrong numbers.
• A welding helmet you can actually see through — an auto-darkening helmet with a good lens is the best money a welding student spends.

Career Pathways

• Welder, cutter, solderer, or brazer — SOC 51-4121.
• Machinist — SOC 51-4041.
• Computer numerically controlled tool operator — SOC 51-9161; CNC tool programmer — SOC 51-9162, the better-paid of the two.
• Structural and construction welding — steel erection and fabrication.
• Pipe welding — process plants, utilities, and shutdown work; among the best-paid work in the trade, and 6G qualification is the gateway.
• Marine and shipyard welding and fabrication — a large Florida sector.
• Aerospace machining and welding — precision work to demanding standards, frequently with certification and clearance requirements.
• Job shop and contract machining — where most newly certified machinists start.
• Tool and die making, and mould making — a highly skilled speciality with long training and strong earnings.
• Quality inspection and metrology — CMM operation and first-article inspection; a route off the machines that uses the same knowledge.
• CNC programming and CAD/CAM — the natural progression from operating, and where the pay increases.
• Maintenance and millwright work in manufacturing, utilities, and theme parks — frequently salaried with benefits.
• Welding inspection — the AWS Certified Welding Inspector credential requires documented experience and is a well-paid career step off the tools.
• Mobile welding and self-employment — real in this trade, and a business as much as a craft.

Special Information

⚠ EDM does what cutting tools cannot — and that is exactly when to use it

• Reach for EDM when a cutting tool cannot do the job, not as a default. It is slower and more expensive per hour than milling, and using it for work a mill could do wastes both.
• Hardness is irrelevant to EDM. Hardened tool steel and carbide cut as readily as mild steel, which is why parts are frequently heat treated first and then EDM'd — eliminating the distortion that would follow machining before hardening.
• Internal sharp corners are EDM's signature capability. A milling cutter always leaves a radius; a wire leaves a corner limited only by the wire diameter.
• It exerts almost no force on the work, so thin, delicate, and deep features that would deflect or chatter under a cutting tool can be produced accurately.
• The material must conduct electricity. This is the process's hard limit, and it rules out plastics, ceramics, and most composites.
• Flushing determines whether it works. Debris must be carried out of the gap; poor flushing causes wire breakage, unstable cutting, and poor finish, and it is the first thing to check when a job goes badly.
• Multiple passes produce accuracy and finish. A rough cut followed by skim passes is standard practice, and expecting a single pass to deliver both is a beginner's error.
• Understand the recast layer. EDM leaves a thin altered surface layer, and for fatigue-critical parts it may need removing — which is a specification question, not an aesthetic one.
• Maintain the dielectric. Filters and deionising resin are consumables, and degraded dielectric degrades everything about the cut.

⚠⚠ Rotating machinery — the rule that matters most is about what you wear

• ⚠⚠ Never wear gloves, long sleeves, a tie, jewellery, a watch, or loose hair near a rotating machine. Entanglement in a lathe is the classic fatal machining accident, and it is fast, and nothing you can do afterwards helps. Sleeves rolled and secured, hair tied back and contained, rings off.
• Eye protection every time, without exception — chips leave a machine at speed and they are hot and sharp.
• Never clear chips by hand. Machining chips are razor-sharp and frequently hot — use a brush or a hook, and never while the machine is running.
• Stop the machine before measuring, adjusting, or touching the work. Every time. There is no measurement worth taking on a spinning part.
• Remove the chuck key before starting. A chuck key left in becomes a projectile, and it is the most common serious lathe incident after entanglement.
• Secure the workpiece and the tooling properly. Work thrown from a chuck or a vice is dangerous to everyone in the shop.
• Know where the emergency stop is on every machine before you start it, and be able to reach it from where you stand.
• Keep guards in place. Removing a guard to see better is exactly the decision that precedes an injury.
• Lock out for setup, tool changes, and maintenance on powered equipment.
• Coolant causes dermatitis and the mist is a respiratory irritant — wash hands, keep it off skin, and use the mist extraction where fitted.
• Keep the floor clear and dry. Chips and coolant underfoot are a slip hazard next to a machine you do not want to fall into.
• Never leave a running machine unattended, especially a CNC on its first run of a new program.

⚠ NIMS credentials are the machining equivalent, and employers know them

• The National Institute for Metalworking Skills (NIMS) issues the industry's recognised competency credentials, and this programme is explicitly aligned to them — CNC Milling and CNC Turning: Programming, Setup & Operations Level 1 are named in the course descriptions.
• NIMS credentials require both a written examination and a performance test — you make a part to specification and it is measured. That combination is why employers value them: the credential certifies you can actually hold a tolerance, not merely describe how.
• Collect every credential the programme offers. They cost little while you are enrolled and the machines and instructors are there.
• The performance test is measured to a written specification. Practise producing parts to print, in-tolerance, on the first attempt — not producing something that looks right.
• Stack the credentials. Measurement and metrology, manual milling and turning, CNC milling and turning, and CAD/CAM together describe a complete machinist.
• Certification fees are usually separate from course fees — budget for them.
• Keep your credential records and your sample parts. A first-piece inspection report and the part it describes are genuinely persuasive at interview.

⚠ A grade of C or better is a progression gate, not a target

• Daytona State states in these course descriptions that a grade of C or better is required to continue in the programme — and in the final courses, to graduate from it.
• This is a cohort programme. Falling below the gate does not merely cost a grade; it can remove you from the sequence until the course is offered again, which may be a full year.
• Ask early what happens if you fall short — repeat policy, how many attempts are permitted, and whether financial aid covers a repeat.
• Practical skill assessments are frequently pass-or-repeat rather than graded on a percentage, and a failed weld test or setup check is exactly the kind of thing that stalls progression.
• Attendance directly affects the outcome in a clock-hour programme where the skill is built by hours on the machine.
• Ask for help before you are behind, not after. Instructors in trade programmes have far more options at week three than at week twelve.
• Use open lab time. The students who pass practical assessments first are almost always the ones putting in unscheduled hours.

⚠⚠ Budget for the laboratory fees and the tools

• Daytona State publishes a laboratory fee for every course in this programme, and in the welding sequence they are substantial — from roughly $390 to $463 per course. The machining courses run lower, roughly $76 to $190.
• PSAV programmes advertise low tuition; the fees and tools are where the real cost sits. Ask the programme for a complete cost sheet before you enrol — tuition, every course fee, tools, textbooks, certification test fees, and personal protective equipment.
• The fees cover genuinely expensive consumables — filler metal, electrodes, shielding gas, plate and pipe stock, cutting tools and inserts, and wear on machines.
• You will need your own personal protective equipment and hand tools. Get the programme's required list early and buy over time. For welding that means a good helmet, jacket, gloves, and safety boots; for machining, measuring tools you will use daily.
• Buy quality where it protects you or determines accuracy. An auto-darkening helmet with a proper shade range, and a decent micrometer and dial indicator, are worth the money; most other things are not.
• Certification test fees are usually separate — NIMS credentials and welder qualification tests both cost extra.
• Ask about workforce funding. Trade programmes frequently have funding routes degree students do not, including employer sponsorship, apprenticeship arrangements, and Florida workforce grants.

⚠⚠ This is a PSAV clock-hour course — it carries no college credit

• The leading zero in the course number is the signal. Under the Florida Statewide Course Numbering System, a 0000-level number denotes postsecondary adult vocational (PSAV) instruction, measured in clock hours rather than semester credit hours. These courses carry zero college credit.
• ⚠ A catalog may display the clock-hour figure under a heading that reads "credit hours." It is not credits. A 0000-level course showing 280 is 280 hours of instruction, not 280 semester credits.
• PSAV hours do not transfer as college credit to an associate or bachelor's degree, and they do not satisfy general education requirements.
• What they produce is a workforce credential — a career certificate plus, in this programme, industry certifications employers ask for by name. For a skilled trade that is frequently exactly the right outcome, reached far faster and more cheaply than a degree.
• Some institutions offer articulation from a PSAV certificate into a related associate degree. ⚠ These are institution-specific and they change. If you intend to continue to a degree, get the articulation in writing from the receiving institution before you enrol.
• Financial aid rules differ for clock-hour programmes — ask the financial aid office specifically about clock-hour programmes.
• Attendance is the currency. Clock-hour programmes track attendance directly and missed hours generally must be made up.

Why metalworking is durable employment in Florida

• Shipbuilding and marine repair — Jacksonville, Tampa, and Port Everglades all support substantial marine fabrication and repair, and marine welding is skilled, well-paid work.
• Aerospace and space — the Space Coast and the wider aerospace supply chain need precision machining and certified welding, frequently to demanding standards.
• Defence contracting across Florida, ⚠ much of which requires U.S. citizenship and sometimes a security clearance.
• Construction and structural steel — sustained Florida construction activity plus storm repair.
• Manufacturing and job shops — general machining work for local industry, and the sector most likely to hire a newly certified machinist.
• Power generation, utilities, and process plants — pipe welding and maintenance, and among the best-paid work in the trade.
• Theme park and attraction fabrication and maintenance — a distinctively Central Florida employer with year-round demand.
• Mobile and rig welding — higher earnings for those who invest in a truck and equipment, though it is a business as much as a trade.
• The workforce is ageing and replacement demand is real — skilled welders and machinists are genuinely scarce, and employers say so.
• Travel and shutdown work pays a substantial premium for those willing to take it.

PMT0228C is 130 clock hours with a $76.55 lab fee, offered fall and spring, with PMT0202C, PMT0251C and PMT0260C as prerequisites. ⚠ Clock hours carry no college credit, and a C or better is required to continue.

EDM competence is a genuinely differentiating skill, particularly for mould and die work — keep examples of what you produce.