TECH School

Learn more about the different types of thread working. Which are the advantages of each technique and what are the specific requirements to realize a thread? The thread often remains the last operation in the work piece and demands therefore a reliable tool solution. DC Swiss will show you in the following links the explicit difference between thread cutting taps, thread forming taps and thread milling cutter.
  • Thread Cutting
  • Thread Forming
  • Thread milling

Thread cutting taps are the most common tools for realizing the female thread. Cutting taps have only few requirements on the machine side and thanks to a large choice of tools there is a solution for any material and any application.

Types of hole

Materials

Tap Geometry

Tap Selection

Tap dimension

Coating


Thread forming is a consistent solution for realizing the internal thread. The swarf remains the biggest opponent when cutting the thread and its evacuation, especially in deep threads and threads with counter-bore, is challenging. With the thread forming tap, the material will not be cut but formed. Thanks to the deforming process, the forming tap avoids creating swarfs or chips and guarantees a high process security with impressive performances.

Range of application

Range of application

All materials with a minimum of 10 % elongation and a tensile strength of up
to 1’150 N/mm2, e.g. steels, stainless steels, pure titanium, aluminium, copper, long chipping brass, etc.

Forming process

Forming process

The polished points and flats of the thread former’s teeth pierce the ductile material and force the material into the space in the tool profile. This creates
the thread profile with its typical groove in the crest.

Advantages

Advantages

  • Higher process security due to the lack of shavings.
  • Only one tool for both, through and blind holes.
  • Optimal for deep threads.
  • Thread with higher resistance of stripping by static and dynamic load.

Application restriction

Application restriction

For physical reasons, thread forming in thin-walled workpieces should be carried out with due care.

Adequate lubrication

Adequate lubrication

The thread forming process generates considerable friction. Therefore the tool must be protected by a film of lubricant. If the supply of lubricant is interrupted, then cold welding will quickly occur, resulting in tool failure.


Thread former FS-DL

Thread former FS-DL

Universal thread former with 4 forming lobes for small thread sizes Ø ≥ 1 – < 3 mm, in all cold forming materials. With “DLC” wear-protective coating with
excellent lubrication and sliding properties. For stainless steels, pure copper, etc.

Thread former FS-VS

Thread former FS-VS

Universal thread former with 4 forming lobes for small thread sizes Ø ≥ 1 – < 3 mm, in all cold forming materials. With DC “VS” tool wear protective coating with high sliding properties.

Thread former FPS-DL

Thread former FPS-DL

For Ø ≥ 3 mm, with large forming lobes designed for a progressive flow
of abrasive materials. With “DLC” wear-protective coating for better gliding and high tool life in long chipping brass and aluminium.

Thread former FPS-VS

Thread former FPS-VS

For Ø ≥ 3 mm, with large forming lobes designed for a progressive flow of materials with low elongation coefficient. With DC “VS” wear- protective coating with thermal and chemical properties. For structural steels, carbon steels, alloy steels, etc.

Thread former FAS-VS

Thread former FAS-VS

For Ø ≥ 3 mm, with pointed forming lobes designed for a fast flow of tough materials with high elongation coefficient. With DC “VS” wear-protective coating with excellent lubrication and sliding properties. For stainless steels, pure copper, etc


Lubrication grooves from Ø 3 mm

Lubrication grooves from Ø 3 mm

Lubricant will be guided to the surface of the tool which is directly in contact with the material.

Without lubrication grooves

Without lubrication grooves

Especially recommended for forming soft materials and for through holes in thin parts (e.g. for sheet metal working).

With internal coolant supply

With internal coolant supply

Highly recommended for deeper threads and for horizontal working.

Correct thread profile

Correct thread profile

Accurate core hole is required in order to form a thread according to the norm.
For materials with a very high elongation coefficient and threading depth > 2 x D, we recommend increasing the core hole Ø by 0.02 to 0.05 mm.

Incorrect thread profile

Incorrect thread profile

Too big profile due to the too small core hole diameter. The required torque is higher. Incomplete profile caused by the core hole diameter being too big


DC solid carbide thread milling cutters and thread whirl cutters for the easy manufacturing of through and blind holes, for right- and left-hand threads, with one only tool used on a stable CNC machine with 3-D-continuous path control.

The DC solid carbide thrillers are a further development of the standard thread milling cutters. Thanks to this combination tool with integrated drill, the core hole does not have to be pre-drilled separately first. The internal thread is cut in one operation, without changing the tool. All DC solid carbide drill thread milling cutters type BGF have internal cooling.

Requirements

  • CNC machine with 3-D continuous path control
  • Excellent machine stability
  • Perfect concentricity of fixture

Program Overview

Programming cycle for thread milling cutters GF - GFH

Tech School - Cycle GF GFH

Programming cycle for thread milling cutters GFS

Programming cycle for thread milling cutters GFM

Specific application cases GF - GFH - GFS - GFM


Thread milling Cycle / Operating Thread Thrilles BGF

Special executions BGF

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