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FAQ

Table of contents

Where can I purchase Thermocompact EDM wires?

Our products can be purchased from numerous distributors throughout the world.

Contact your usual retailer in order to get the wire best adapted to your needs.

If they do not have any of our benchmarks, contact us via the after-sales section of the customer space.

Where should I store the wire reels' cardboard boxes?

They must be kept in a cool, dry place. Stored this way, the wire reels inside the cardboard boxes can be used up to one year after they have been made. However, be careful: the bare brass wires must not be exposed to the slightest amount of ammonia. Ammonia can often be found in cleaning products.

Where should I store an unpacked wire reel?

It is highly recommended to only unpack the reels right before using them. It is essential to store the unpacked reels at a temperature of less than 25C and in relative humidity (less than 50% RH). Reels which have been unpacked for more than a week should not be used. The reels should preferably be placed with their axes horizontal. The end of the wire should be properly fixed. If a couple of turns have moved and the wire seems tangled, hang the reel up by its axis, vertically, and reel down these turns, in order to obtain optimum unwinding of the wire again. This only takes a couple of minutes, and saves a reel or a machining!

Which technology should I use with a coated wire?

First of all, the wire diameter should be respected, as well as its hard, semi-hard or annealed state (900N, 500N, 400N). The new Thermocompact coated wires do not require technological adaptation (offsets, time lags) as regards the technologies existing on the machine. For Agie and Charmilles machines, you will find below a correspondence with the names of the original technologies.

Hard wires (900N)

Family Reference wire New compatible high-performance wires Agie technology Charmilles technology
Bare brass WB 900 SD, SE BCA LT
Zinc-plated brass SWA, CCA SA CCA ST
Laminated brass SWD, CCD SE CCD  
Laminated copper basis SWX, XCC TEX   XS

 

Semi-hard (500N)

Family Reference wire New compatible high-performance wires Agie technology Charmilles technology
Bare brass WB 500 SD 500   LS
Zinc-plated brass SWS   CC SS

 

Coated wires (400N)

Family Reference wire New compatible high-performance wires Agie technology Charmilles technology
Coated brass WB 400     LR
Laminate coated brass SWW   CCW SR

What should I do with empty reels?

Thermocompact reels are made of recyclable plastic. They bear the recycling symbol (§) for the PS, or (7) for the ABS.

Why do coated wires machine faster than bare brass wires?

Each spark generated at the surface of a coated wire removes more matter from the part than a spark of equal intensity generated at the surface of a bare brass wire.

It is as if the energy coming from a coated wire was directed more at the part than at the wire.

Why do coated wires break less often than bare brass?

A recurrent cause of wire breaking is its overheating in the sparking zone. Coated wires conduct electricity better than bare brass wires. They overheat less thanks to the Joule effect, and can take difficult sparking conditions better.

Moreover, coated wires accurately turn the energy of each spark towards the piece that is to be machined. These sparks do not overheat them as much as bare brass wires sparks do.

Less overheated, coated wires do not break as easily as bare brass wires.

Are coated wires more precise than bare wires?

Yes they are, in the same sparking conditions, the coated wire wears out more slowly than bare brass . Its machining precision is better. Be careful to respect the wire unwinding speed prescribed by the manufacturer.

Can coated wires produce better surface conditions than bare brass wires?

Yes, they can. Some coated wires have been designed to get very fine surface conditions, such as Thermo SW and Thermo A wires. Thermo SA wire can attain extremely fine surface conditions, up to Ra=0.05um in tungsten carbide.

Some coated wires are limited as regards minimum roughness (Ra around 0.4um). This is mainly due to their ability to machine very quickly. This is the case for XCC and SE wires. Getting fine machining requires a careful choice of the wire as well as appropriate storing conditions. Getting fine surface condition requires a close selection of the matter to be machined as well as a well set machine.

Do coated wires clog the guides more than brass?

No, today’s latest generation coated wires are designed to leave as little residue as possible in the guides: they are very clean. The amount of residue coming from a Thermo TEX or Thermo SA wire is greatly inferior to the one left by most bare brass wires. As any EDM wire of which good quality is expected, coated wires must be stored with care.

Do coated wires clog filters more than bare brass?

No, an electro erosion wire loses an average of 5% of its mass while machining (rough draft and finishing touches included). The majority of wire lost while machining is caught by the filters.

With every spark, a coated wire loses appreciably less matter than a bare brass wire. This results in less dust in the filters.

After the machining, the matters found in a filter are made up of:

  • About 33% of oxygen and organic matter
  • About 33% of copper and zinc
  • About 34% of iron and chromium, in case of tool steel machining.

Does a machining stage use the same amount of coated wire as bare brass wire?

The same machining takes 20 to 40% less coated wires than bare brass wires.

How much time is wasted by using a bare wire instead of a coated one?

For the same machining, the sparking time with bare brass is 30 to 70% longer than with a coated wire.

Concrete examples are given in this site.

Apart from machine movements against which manufacturers have introduced security regulation devices, there remain considerable dangers:

  1. Fire
  2. Explosion
  3. Cutting oneself with a wire

Wire electro erosion safety

1: Fire

A fire can happen in the case of a short circuit between the wire used and the mass of the machine.

These short circuits usually happen:

  1. On unwinding the reel, when an ill-fixed piece of wire touches the machine mounting.
  2. On the course of the wire, because of a belt or insulating material wearing out.
  3. On evacuating, if the wire has not followed the planned course towards the used wire container (if it has drifted from its course while reeling)
  4. If the used wire spills out of the container

Considering the consequences of a fire, it is highly recommended to have fire detectors and automatic extinguishing devices.

2: Explosion

Explosions are very rare. They can happen though, for sparking parts gives off hydrogen. One can see this gas being given off during the rough draft: tiny bubbles come out of the machining slot.

Pockets of this explosive gas can form in the cavities of the machined parts, especially in the inner sides of some big parts. On contact with air and a spark, the accumulated hydrogen may explode.

It is recommended not to leave any cavity unventilated on the parts, or to use sprinkling rather than laying underwater, in well ventilated premises.

3: Getting cut with a wire

The wires are very sharp on the skin. One must avoid catching them around a finger or a hand while the machine is pulling them. In some extreme cases, a wire may cut off a finger.

EDM wires safety sheet

Although they are not materials in themselves, Thermocompact EDM wires have a common safety sheet. What is more, a radioactivity control is performed on production output to guarantee the absence of abnormal ionizing radiations.