Some of a given tool holder is inherently better than another, due to some aspect of how it was created.
On the best case-scenario the slightly different quality of a tool holder results in its slightly different durability. It means that all reliable manufacturers make tool holders that provide a high quality interchangeable interface between a machine spindle and a cutting tool, but, depending on the brand, one tool holder will worn out a little bit earlier than another.
However, the best case-scenario is not the only one possible.
Unfortunately, Tool Holder Industry is an easy place for unscrupulous manufacturers and sellers to market their poor quality tool holders. Substandard tool holders may damage both machine spindles and cutting tools, not to mention expensive work-pieces and the whole costly manufacturing process. For this reason many tool holders presented on the market can be rightfully called Counterfeits.
How to detect counterfeit products?
The most effective and reliable indicator is a low, unrealistic price.
Not all tool holders are made equal: some of them are made of cheap materials and are not subjected to a sufficient processing. Cheap material and lack of processing (e.g. metal hardening and grinding) result in a low price and quality which is worth the price.
Please, be very attentive buying tool holders (as well all other goods) if the price is too attractive to be true.
Recently we came across some quite attractively cheap tool holders claimed to be made in Germany. Being in Tool Holder Industry for 15 years and knowing the price and the value, we could not believe in the slightest possibility of a decent quality at this price level. We decided to check the quality of tool holders allegedly made in Germany. For this purpose we have purchased two tool holders.
Please, see below the results of our investigation:
We tested 2 heads purchased from company X, Germany.
1. HRC measurement made in 3 points showed surface hardness of 18 HRC, meaning that that the heads had not been subjected to any hardening.
Heads, not previously hardened, are considerably cheaper as hardening process does not take place first of all, these heads are easier to process, the second, and there is no need to buy expensive carbide tools – the third.
Such heads have weaker rigidity and lose their accuracy faster.
Pay attention to the Fig.3. A clearly visible fade appeared after just one (!) installation of the head on a machine.
The heads are made in violation of the terms of accuracy.
n standard manufacturing process, after the rough cutting and milling and drilling, tool holders are subjected to heat treatment for several hours. After the heat treatment the material becomes very hard: Tungsten Carbide steel tools are required to finish the job, and more time is spent to do fine milling, rough and fine boring, grinding.
Quality inspection of the cheap "German" tools allows making the following conclusions:
- the tools were not subjected to a heat treatment: none Carbide Tools were used and the manufacturing process was extremely short and easy;
- position of holes is incorrect: when the tool holder is mounted on the turret, its position will be oblique;
- the distance form center is shorter, than the required standard;
- the teeth are soft and very easy to damage: repeated mounting and dismounting of the tool holder will affect accuracy, and burrs will show up;
- quality of spacer is very bad;
- rigidity is very bad.
3. Engagement teeth are subjected to grinding after blackening. The Fig.4. shows that blackening has not been removed completely during the grinding.
So the question is: what was made inaccurately – teeth or grinding? Or, maybe, both!
4 .The Fig.5. shows how inaccurate the edges of the head are. For comparison, there is a head of good quality next to the bad one.
5. As a result of bad machining, chip appeared to be left in the coolant through hole. See the picture.
This chip can unexpectedly come off, shut off the coolant nozzle and thus interfere with the machining process.
6. Stains of white paint, resembling some sort of marking, are noticeable in the Fig.1. It suggests the overall low level of production standards of the enterprise. Obviously the factory was not ISO9000 certified. We believe this kind of marking can hardly be found on any product made in Germany.
Finding such a "bouquet" while examining just 2 heads leads to a conclusion about an extremely poor quality of this product. No price, how attractive it could be, should confuse you when dealing with such an obviously sloppy job.
How to avoid a poor product? Speak to a respectful company first. If in doubts, we are always ready to help with a consultation. Please contact us.