Short Machine Tap Form C HSS-G - NPT 1.1/2 x 11.5
€160.50
VÖLKEL Short Machine Tap Form C HSS-G - NPT 1.1/2 x 11.5
The VÖLKEL single-cut tap is the ideal solution for efficiently and precisely cutting NPT threads in a single operation. Made from high-quality HSS-G steel and designed according to Form C, this tool is suitable for both manual and machine use.
What is a single-cut tap? NPT and Form C explained
A single-cut tap is a tool that cuts the complete thread in a single pass. Unlike multi-piece sets, where the thread is created step-by-step with taper, plug, and bottoming taps, the single-cut tap does this in one pass. This saves time and simplifies the work process.
Form C refers to the chamfer of the tap. It describes the chamfer length, which for this tool is about 2 to 3 threads. This short chamfer facilitates the start of the cut and is particularly advantageous for blind holes or thin-walled workpieces, as it allows for a faster cut.
NPT stands for "National Pipe Taper" and is an American tapered pipe thread with a taper of 1:16. This conical shape causes the thread to wedge tightly into the mating part when screwed in, creating a self-sealing connection. This often makes additional sealants unnecessary and ensures leak-free connections, especially in pipeline construction.
The designation NPT 1.1/2 x 11.5 means that it is an NPT thread with a nominal size of 1 1/2 inches, which has 11.5 threads per inch.
Step-by-Step Guide to Use
Although it is a single-cut tap, the following steps should be followed for an optimal result:
- Preparation: Pre-drill the core hole with the correct diameter. For this thread, the hole must have a diameter of approx. 44.5 mm. Deburr the hole to ensure a clean start.
- Clamping: Secure the single-cut tap firmly in a suitable tap wrench with the square drive of 29 mm or in a threading machine.
- Aligning: Place the tap perpendicularly on the hole. It is crucial that the tap is aligned straight to avoid a crooked thread.
- Cutting: Apply light, even pressure and turn the tap clockwise. After every 1/2 to 1 turn, turn back a quarter turn to break the chips. Cutting oil should be used continuously to minimize friction and extend the tool's life.
- Completion: Cut the thread until the desired depth is reached. Since the tap cuts the complete profile in one pass, the thread is immediately ready for use.
Frequently Asked Questions (FAQ)
1. What is the main difference from a 3-piece tap set?
A single-cut tap cuts the entire thread in a single operation. A 3-piece set uses separate tools for tapering, plugging, and bottoming, which makes the process more gradual, but can be advantageous for very hard materials or very large threads.
2. What does HSS-G mean?
HSS-G stands for "High Speed Steel, Ground". It describes a high-quality high-speed steel material whose cutting surfaces are precisely ground. This results in sharper blades, higher dimensional accuracy, and a longer tool life.
3. Can I use this tap for stainless steel pipes?
This tap is designed for well-machinable materials up to 900 N/mm². Stainless steel often has a higher strength and toughness. For stainless steel, a special tool with a suitable coating and geometry is recommended to increase tool life and ensure process reliability.
4. Can NPT threads be re-cut?
Since NPT threads are conical and seal by wedging, re-cutting is generally not recommended. Any re-cutting removes material, which impairs the fit and thus the sealing effect. If necessary, a new hole should be provided with the correct thread.
5. What role does the taper of 1:16 play?
The taper of 1:16 is the most important characteristic of the NPT thread. It ensures that the thread seals itself when screwed in. The tighter the connection is, the more the flanks wedge into each other, guaranteeing a leak-free connection.
| Type of thread | american tapered pipe thread, taper 1:16 |
|---|---|
| Standard | DIN |
| Form | Form C |
| Material | HSS-G |
| Tolerance | medium |
| Size | NPT 1.1/2 x 11.5 |
| Overall length (L1) | 140 mm |
| Thread length (L2) | 42 mm |
| Core hole diameter (D1) | 44.0 mm |
| Shank diameter (D2) | 36.0 mm |
| Drive connector | 29.0 mm |
| EAN | 4022835635420 |
| Item number | 63542 |
| Type of flute | straight fluted |
| Application | for through and blind holes |
| Thread standard | ANSI B1.20.1 |
