Parts, materials and finishes
The part that wears out must be replaceable
Almost every tool has an area that works harder than the rest. If that area is part of the main component, when it wears out, the whole tool is worn out. Designing it separately, and making it reversible, extends its life by years.
A cutting table for splicing rolls. The operator runs a utility knife through a groove that guides it in a straight line. Thousands of times. Every day, across three shifts.
The previous tool was an aluminium plate with the groove machined directly into it. It worked until it stopped working: over the years, the blade widened the groove, the knife started wandering, and the cut stopped coming out straight.
The problem was not aluminium. Aluminium is a good material for a table: light, stable, easy to machine. The problem was asking the same material to be both a table and a blade guide.
Separate the working part from the supporting structure
On the new table, the groove is not in the table. It is in a removable strip fitted into it.
That changes three things:
- Each part can use the material that suits it. The table remains aluminium. The strip is made from a much harder, hardened material that resists friction from the blade.
- When the guide wears out, you replace the guide. Not the table.
- The table is never disturbed. Its supports, stops and clamps remain exactly the same from the first day to the last.
It is a very simple rule that applies to any tool: identify the area that will suffer wear and make it a separate part.
Two lives instead of one
The strip has one more detail: there is a groove on each face.
If one deteriorates over time, the strip is removed, turned over and work continues with the other. Before a new one needs manufacturing, the part has a complete second life.
It is a trick that costs very little at the design stage—machining the same groove twice—and doubles the service life of the hardest-working part.
A groove designed for the tool actually used
There is another decision you cannot see that has a lot to do with getting a clean cut.
The groove was made as fine as possible: using a tapered cutter, leaving a width of 0.25 mm at the bottom. Just enough to keep a standard utility knife properly guided, without clearance that would let it wander.
This has two advantages. The blade is genuinely guided, and the cut comes out clean. And the cutting tool is the usual one: available from any hardware shop, with a replaceable blade whenever needed, without depending on a special blade.
Five years on, and still unused
The table was built in 2021. It is used daily across three shifts, shared between two machines.
Five years later, the strip has still not needed turning over. The first face is still working.
That is the best evidence that the decision was right. With the right material in the working area, the wear part has turned out to wear very little. And the second face, for now, is insurance nobody has needed.
How to apply it to any tool
This is not just about cutting tables. It applies to stops, guides, supports, dies, jaws and almost any tool used repeatedly.
- Find the area that will wear. Where the tool rubs, where the part strikes, where the same thing always bears against it.
- Make it a separate part, easy to remove and fit.
- Give that area the material it needs, even if the rest of the tool uses another.
- If possible, make it reversible. Two faces, two lives.
- Make replacement possible in the workshop, without redesigning anything.
- And design for the tool that will actually be used, rather than an ideal one.
The whole tool lasts for years. The working part lasts as long as it lasts, and when it is finished, it is replaced in five minutes.
At 7Axis Industrial, we design tooling with its service life in mind too: what wears out, when, and how it can be replaced without rebuilding everything.