Hand Tap set of 3 pieces HSS-G - Tr 16 x 4

This hand tap set is perfectly suited for:

• General Use: In the workshop, in mechanical engineering, and for industrial applications.
• Materials: Ideal for well-machinable materials up to 900 N/mm², such as unalloyed and low-alloy steels.
• Holes: For cutting threads in through holes and blind holes.
• Usage Type: Specially optimized for manual use with a tap wrench.

The set consists of three perfectly coordinated taps, each cutting a specific part of the thread:

• Taper Tap: With one ring marking on the shank. This tap pre-cuts the thread.
• Second Tap: With two ring markings. It deepens the pre-cut thread.
• Bottoming Tap: Without a ring marking. It cuts the thread to its final depth and correct profile.

A trapezoidal thread (Tr) is a special thread form characterized by its trapezoidal profile. Unlike the pointed flanks of metric ISO threads (like M threads), the flanks of trapezoidal threads are inclined at 30° and the tops and bottoms of the threads are flat.

The DIN 103 standard specifies the exact specifications for metric ISO trapezoidal threads. These threads are known for their high load capacity and resistance to dirt and are frequently used for lead screws.

Key Differences:

• Profile: Trapezoidal profile (Tr) as opposed to the triangular profile of metric threads (M).
• Application: Trapezoidal threads are primarily designed for transmitting large forces and movements (e.g., in machine tools, lifting platforms), while metric threads are mainly used for pure fastening elements (e.g., screws and nuts).
• Self-locking: Trapezoidal threads are generally not self-locking, which means that a load acting on the spindle can continue to move without further force application.

The designation Tr 16 x 4 means: a trapezoidal thread with an outer diameter (nominal size) of 16 mm and a pitch of 4 mm.

For an optimal result, follow these steps:

1. Prepare the Hole: Pre-drill the core hole with the appropriate diameter (in this case, about 12 mm for the Tr 16x4). Deburr the hole to ensure a clean start.
2. Clamp the Tool: Take the taper tap (one ring) and clamp it securely in a suitable tap wrench with the 9 mm square drive.
3. Set and Cut: Place the taper tap perpendicularly on the hole. Apply light, even pressure and turn the tap wrench clockwise. After every half turn, turn a quarter turn back to break the chips and facilitate the cutting process.
4. Lubricate: Use a suitable cutting oil throughout the process to reduce friction, extend the tool's life, and improve the quality of the thread.
5. Change Taps Step-by-Step: Switch successively to the second tap (two rings) and the bottoming tap (no ring) and repeat the cutting process until the thread is cut to full depth.

1. What is the main difference between a trapezoidal thread and a metric thread?

The main difference lies in the profile shape and the intended use. Trapezoidal threads have a flat, trapezoidal profile and are used for transmitting movements and forces. Metric threads have a pointed, triangular profile and serve primarily as fastening threads for screws and nuts.

2. Why is a 3-piece set used?

A 3-piece set allows for a step-by-step cutting of the thread. Since trapezoidal threads generate large chip volumes, a set of taper, second, and bottoming taps distributes the load among several tools. This protects the taps and ensures a clean, precise, and dimensionally accurate thread.

3. Can I use this set for left-hand threads as well?

No, this set is designed for cutting right-hand threads. For left-hand threads, you need a special set that is marked accordingly (e.g., with "LH" for Left Hand).

4. What does HSS-G mean?

HSS-G stands for "High Speed Steel, Ground." It is a high-quality steel material where the cutting surfaces are precisely ground. This ensures sharp cutting edges, high accuracy, and a long tool life.

5. How do I choose the correct core hole for the thread?

The correct core hole for a trapezoidal thread is calculated from the outer diameter (nominal size) minus the pitch. For Tr 16 x 4, this would be 16 mm - 4 mm = 12 mm. It is crucial to use the correct core hole diameter to ensure the quality of the thread.