Keeping things in proportion: challenges in tool and mould making

To ensure success at every step, you need two things for each phase. These are: the expertise to know which machining strategy best suits the customer’s needs, and a well-stocked range of high-quality tools with long tool lives. If you have these basic things in place, then your work will proceed with the same level of efficiency, regardless of whether you are working on tools, simple geometries, or highly complex 3D shapes – and irrespective of whether it involves hard or soft machining. Then you’ll be milling, drilling and clamping with confidence, and grinding with precision – right down to the micrometre.

By choosing the right tool, you can assure the following:

• Receive reliable cutting data
• Improve chip evacuation
• Extend tool life, leading to increased wear mark width
• Make best use of the cutting edge length in milling cutters
• Improve surface quality
• Reduce running times
• Standardise the display of measured values

Standard components are great – as long as they meet what is required by the specific tasks in mould construction and tool manufacture. To achieve optimal force transfer, you must fix the blank or material to be worked on and the tool firmly in place. The biggest obstacle to overcome is complex tool geometry. It is often necessary to clamp and release the blank several times to guarantee the dimensional accuracy of the tool’s final shape at the end of the milling and drilling processes.

It does not matter whether you are working on multi-task machines such as milling and turning centres, tool clamping systems with polygon tapers, or hollow shank tapers with flat surface contact. The fewer tolerances your arbor has, the easier it will be to avoid angular errors and height errors.

The following arbors are available:

• ISO taper arbor
• Hollow shank taper arbor
• ISO taper arbors with flat surface contact/double-contact arbors
• MTM tool systems
• Tool clamping systems with polygon tapers

For work that permits direct clamping of the blank on the machine table, lateral toggle clamps or claw clamps are a good choice. If you work mainly on machining centres and milling machines, then high-pressure vices, centring vices and machine vices may be useful to you. When choosing the right technology for your business, always note the programming effort. The only way for you, as a master craftsperson in tool and mould making, to truly benefit is if the process and programming both proceed with equal efficiency.

If you would like to speed up your whole process, whilst taking into account all the clamping processes, our experts will explain all the technical options to you.
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Steel is not just steel – check it closely!
In your work as a master craftsperson or specialist in tool and mould making, the most important things are:

1. The alloy element in your steel
2. The possibility of heat treatment

What you absolutely must know about steel in tool and mould making:

• Austenitic stainless steels: easy to machine.
• Super-austenite: extremely difficult to machine
• Ferritic stainless steels: have a tendency to stick, but are mechanically easy to work with
• Martensitic stainless steels: machining can vary depending on the pre-treatment (annealed or tempered)
• Austenitic-ferritic stainless steels (Duplex steel): extremely high tensile strength and heat-resistance, difficult to machine

A lighter option – using aluminium or aluminium alloys

If it is an option for you, there is a lot going for aluminium. It is a light material which is generally easy to machine. Compared to steel of the same strength, with aluminium, you can benefit from more favourable cutting forces during your work. As an experienced metalworker, you know that the chip shape is important, due to the relatively large possible chip volume. The chip shape depends both on the material itself and on the cutting conditions and tool geometry. If you value long tool lives in your work process, then tools made of High Speed steels (HSS) and carbide are well-suited to machining wrought aluminium materials.

Important:

• Pure aluminium and hardenable wrought materials in the soft state tend to form spurious chips or built-up edges, particularly at low cutting speeds. This can result in poor surface quality.
• The cutting properties of aluminium cast materials without silicon are approximately the same as those of the corresponding wrought materials.
• Hardenable and hypoeutectic al-si cast alloys are harder to machine. This property increases with a higher silicon content. In this case, carbides are a good option.
• For hypereutectic al-si cast alloys, it is best to use carbides or polycristalline diamond tools. Important: the coarse silicon particles in the relatively hard basic structure significantly reduce the tool life.