Three methods of thread machining with thread milling cutters

I. Helical milling of internal holes

1. Processing range

Blind or through holes with large bore diameters are often machined by spiral milling as twist drilling is too slow or impossible. Moreover, as the tool chosen for this method does not have a bottom edge, it is more suitable for small depths of cut, high speeds and large feeds.

2. Machining characteristics

Helical milling of holes is based on the helical undercutting method. One feature of helical milling of holes is that for every week of helical milling, the tool moves one undercut height in the Z-axis direction.

3. Selection of the thread milling tool

Choose a 16mm three-flute indexing cutter with a tool speed of S=3000r/min and a feed of F=2500mm/min.

4. Description

This method is unique in spiral milling of internal holes. The essence of its programming is to program a subroutine with an undercut height as the height of the spiral and to complete the milling of the entire hole by cyclically calling the spiral subroutine. This method is not affected by factors such as milling tool specifications, so it is ideal for use on CNC milling machines and machining centres.

5. Program writing

Second, single-edge thread milling cutter processing thread

1. Processing range

The same thread milling cutter can be used for both left-hand and right-hand threads, and for both internal and external threads, regardless of pitch and thread size.

2. Machining characteristics

The single-edge thread milling cutter is based on the helical undercutting method. The principle of thread milling is that for each week of thread milling, the tool moves one lead in the Z-axis direction (one pitch in the case of a single thread).

3. Selection of the thread milling cutter

Choose a 16mm single flute thread milling cutter with a tool speed of S=1800r/min and a feed of F=300mm/min.

4. Description

This method is unique in thread milling in that the essence of its programming is to compile a lead spiral into a subroutine, and by repeatedly calling up this spiral subroutine for machining, the entire thread can be milled. This method of thread machining is not affected by parameters such as milling tool pitch or thread size, and is therefore widely used on CNC milling machines and machining centres.

5. Programming

3. Multi-flute thread milling cutter for threads

1. Processing range

The same thread milling cutter can mill both left-hand and right-hand threads, as well as internal and external threads, and is mainly used for high productivity applications.

2. Machining characteristics

Each milling cutter has a value which is the programmed value for the radius of the tool fillet, i.e. the tool radius compensation value when milling threads. When milling threads, the general depth of machining can be completed in one pass, but if multiple passes are required, this can be done by modifying the tool compensation value.

3. Selection of the thread milling cutter

The effective length of the thread milling cutter is generally greater than 20 mm, with a 1.5 mm pitch multi-flute thread milling cutter, tool speed S = 1200 r/min and feed F = 100 mm/min.

4. Description

This method is very efficient when it comes to thread milling and the programming is very simple. The essence of its programming is that the thread milling cutter is imported (or exported) for 1/4 of a week in the XOY plane and the thread is formally machined for 1 week; the tool runs for 1/4 pitch when it is imported (or exported) for 1/4 of a week in the Z-axis direction and for 1 pitch when the thread is formally machined for 1 week in the Z-axis direction. The entire thread is milled by ensuring that every effective tooth on the multi-flute thread milling cutter is involved in milling at the same time. The focus of this method of thread machining is on the selection of the pitch of the milling cutter: when a thread of a certain pitch is required, the corresponding thread milling cutter must be selected. The method is influenced by the pitch of the milling cutter and the thread size, but is widely used on CNC milling machines and machining centres due to the high efficiency of the process.

5. Program writing

The above is the UB Tools for you to introduce the three thread processing methods about thread milling cutter for your reference, about more professional issues, you can consult us in detail.

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