Hand taps

Discover our range of high-quality RUKO hand taps for the manual production of precise internal threads, primarily in metal. Hand tap sets enable controlled thread cutting without the need for a stationary threading machine and are therefore suitable for a variety of manufacturing, assembly and maintenance tasks.

Hand thread cutters are available in various thread types, set configurations and tool materials. When making your selection, the desired thread, the material to be machined and the application requirements play a decisive role.

A hand tap is a tool used for manually cutting internal threads. During the thread-cutting process, the intended thread profile is created as the cutting edges remove material from the centre hole.

The hand tap is clamped into a suitable tap wrench and guided by hand. The internal thread is produced in stages by using several coordinated tools in succession, depending on the thread type and design.

As the material removal is spread over several machining steps, the load on the individual tools is reduced and the thread is machined in a controlled manner to the intended geometry.

You can find detailed step-by-step instructions in our how-to article “How do I cut an internal thread in 3 steps?”

Hand taps are particularly suitable for machining tasks where internal threads need to be cut by hand, reworked or inserted in hard-to-reach places.

Typical applications include:

• Cutting individual internal threads
• Repairing and reworking existing threads
• Assembly and fitting work
• Thread cutting directly on the workpiece or on site

Hand thread cutters offer a controlled method of producing precisely fitting internal threads, particularly for flexible and non-automated machining tasks.

The RUKO range includes hand taps for various threading systems and machining tasks. Depending on the application, there are different thread types, set configurations and tool designs.

Metric standard and fine threads

For metric screw connections, RUKO offers hand taps for M standard threads and MF fine threads.

Metric standard threads are among the most common thread types used in mechanical engineering, plant engineering and metalworking.

In addition, hand taps for left-hand threads are available for selected metric applications.

Other thread systems: G, BSW, UNC and UNF

In addition to metric threads, the RUKO range also includes hand taps for other internationally used thread systems.

These include:

• G threads for cylindrical pipe threads
• BSW threads based on the British Whitworth system
• UNC threads (American threads with a coarser pitch)
• UNF threads (American threads with a finer pitch)

A key feature of traditional hand taps is that the thread-cutting process is divided amongst several tools. In this way, the thread is gradually shaped into the intended form.

Taper tap

The taper tap begins by forming the thread profile and carries out the initial material removal. It accounts for approximately 50 per cent of the total chip removal. Its longer cutting edge facilitates positioning and guidance within the prepared centre hole.

Second tap

The second tap deepens the thread that has already been started and continues to shape the thread geometry. It accounts for approximately 25 per cent of the total chip removal. In this way, the necessary machining work is distributed across an additional machining step.

Final tap

The final tap completes the thread. It accounts for approximately 25 per cent of the total chip removal. The appropriate screw can then be inserted into the fully cut internal thread.

In classic three-piece hand tap sets, the individual tools can also be distinguished by their ring markings: the taper tap is marked with one ring, the second tap with two rings, whilst the final tap has no ring marking.

There are also hand tap sets that do not consist of three tools. The RUKO range also includes two-piece versions.

The key factors in selecting a hand tap are the thread type, tool material, material to be machined, centre hole diameter and cutting direction.

Thread type, size and pitch

The hand tap must be suitable for the intended screw connection. The following factors are crucial:

• Thread type
• Nominal diameter
• Thread pitch
• Cutting direction

For metric threads, the nominal diameter and pitch are particularly important. For UNC, UNF and BSW threads, the respective inch-based thread specifications apply.

Tool material: HSS and HSS-Co 5

RUKO hand taps are manufactured from HSS or HSS-Co 5.

HSS is suitable for many common applications in manual thread cutting and, depending on the tool design, can be used on steel, aluminium, brass and other engineering materials.

HSS-Co 5 exhibits higher resistance to heat hardening due to its cobalt content and is therefore also suitable for more demanding materials such as stainless steel.

Materials to be machined

Depending on the tool design, RUKO hand taps can be used for various materials. These include:

• Steel
• Stainless steel (HSS-Co 5)
• Aluminium
• Brass
• Bronze
• Plastics

Not every version is equally suitable for all materials. The material and product version should therefore be selected to suit the specific application.

Further technical features of internal thread cutters and their influence on tool selection can be found in our article 6 Features of Internal Taps at a Glance.

Right-hand or left-hand threads

For specialised applications, left-hand threads are required in addition to the standard right-hand threads. With left-hand threads, the thread direction is the reverse of that for right-hand threads.

RUKO also offers left-hand cutting hand taps for selected metric sizes. The cutting direction must be taken into account when selecting the tool.

Before using a hand tap, a pilot hole must be drilled. The diameter of the pilot hole must be selected to match the thread to be cut.

Twist drills are used to create the pilot hole. The required diameter depends on the type of thread and the nominal diameter and can be found in the relevant tables.

The preparation of the bore also influences the subsequent machining process. A cleanly machined and correctly dimensioned centre hole lays the foundation for a dimensionally accurate internal thread and reduces unnecessary stress on the tools.

Friction is generated during manual thread cutting. Appropriate lubrication can aid the cutting process and reduce tool wear.

The hand tap should also be guided as perpendicular as possible to the centre hole. Guiding the tool at an angle can impair the thread geometry and increase the load on the tap.

To ensure a dimensionally accurate internal thread, there are a few basic points to bear in mind during preparation and use:

• Select a suitable hand tap for the type of thread.
• Adhere to the specified centre hole diameter.
• Always reverse the hand tap while cutting to break up the chips.
• Use the appropriate multi-piece set in the specified order.
• Use suitable coolant.
• Check the cutting edges regularly for wear or damage.

A controlled working method reduces stress on the tool and helps to ensure consistent results when cutting threads by hand.