Yellow ring
VÖLKEL Yellow ring HSSE taps
The yellow ring taps have been specially developed for the precise processing of aluminium and aluminium alloys. The taps deliver maximum process reliability, long service life and excellent thread quality. VÖLKEL yellow ring taps are available for metric threads up to M 30 and for American UNC threads.
- Aluminium, unalloyed
- Aluminium alloys Si < 0.5%
- Magnesium, unalloyed
What are the characteristic properties of aluminium and why should specialised taps be used for this material?
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VÖLKEL HSSE Yellow ring taps
Aluminium behaves differently to steel or cast materials during machining, particularly when thread cutting. Many types of aluminium are soft to medium-hard and easily malleable. This makes aluminium a generally easy material to machine. However, when thread cutting, aluminium usually forms long, tough chips that tend to stick. The aluminium then easily adheres to the tool surfaces. This results in the risk of chip packing and chip accumulation on the cutting edge (built-up edge, BUE). Clogging of the cutting edges can cause the threads to become imprecise, have a degraded surface finish and can lead to easier breakage of the tap.
Taps for aluminium
VÖLKEL HSSE yellow ring Taps are particularly suitable for tapping in aluminium, aluminium alloys (silicon content < 0.5%) and magnesium (unalloyed).
Advantages: The taps have extra sharp cutting edges and a particular cutting geometry. The two flutes (with a 40° right-hand spiral) and large chip gullets ensure improved coolant/lubricant supply and also significantly improved chip evacuation. The quality of the cut threads is improved and the risk of tool breakage is reduced.
⚠️ HINT: For more effective processing and to achieve a higher thread grade, it is recommended to use petroleum as a cooling lubricant when thread cutting in aluminium. Alternatively, special thread cutting oils for non-ferrous metals or emulsion can also be used.
The materials table contains some examples of application with material numbers and tensile strength which are suitable to cut with the VÖLKEL yellow ring HSSE machine taps.
| Material number | DIN | AISI | AFNOR | JIS | Tensile strength min./max. |
|---|---|---|---|---|---|
| 3.1645 | EN AW-2007 | AA2007 | A‑U4Pb | A2007 | 370 - 470 N/mm² |
| 3.1655 | EN AW-2011 | AA2011 | A-U5PbBi | A2011 | 270 - 315 N/mm² |
| 3.1325 | EN AW-2017A | AA2017A | A-U4G | A2017 | 245 - 340 N/mm² |
| 3.3315 | EN AW-5005A | AA5005A | A-G0.6 | A5005 | 145 - 185 N/mm² |
| 3.3547 | EN AW-5083 | AA5083 | A-G4.5MC | A5083 | 275 - 315 N/mm² |
| 3.3211 | EN AW-6061 | AA6061 | A-GSUC | A6061 | 180 - 290 N/mm² |
| 3.4365 | EN AW7075 | AA7075 | A-Z5GU | A7075 | 480 - 540 N/mm² |
Material number: The material number is a standardised, unique identifier for technical materials for a reliable identification. The material number consists of a main group number, separated by a dot from the four-digit grade number. The main group indicates the main material group (e.g. a 1 for steels). The subsequent grade number designates the exact material grade within the main group and also includes properties such as alloy type (chemical composition of the material).
Example (simply explained): 3.1325 (main group 3 = non-ferrous metals / grade number 1325 = defines the specific aluminium alloy with purity and temper) = In the EN AW-2017A (AlCuMg1) alloy, the aluminium contains copper (Cu), magnesium (Mg) and manganese (Mn), among other elements, which account for approx. 3% of the base material (Al). This material is easy to machine and is therefore also well suited for thread cutting.
DIN: Deutsches Institut für Normung, AISI: American Iron and Steel Institute, AFNOR: Association Française de Normalisation, JIS: Japanese Industrial Standards