Short Machine Tap Form C HSS-G left hand thread - NPT 1/8 x 27 LH

• for general use
• non abrasive material up to 900 N/mm²
• unalloyed and low alloyed steel
• for thread cutting by hand and machine
• for through and blind holes

1. Drill core hole: Drill the tapered core hole for the NPT thread with the correct diameter. You can find the exact dimensions in an appropriate thread table for NPT threads.
2. Prepare the tool: Securely and straightly clamp the tap in a tap wrench for manual use or in the holder of your machine.
3. Lubrication: Apply plenty of cutting oil to the tap and the drill hole to reduce friction and ensure a clean cut.
4. Cut the thread: Position the tap straight and slowly turn it in the left-hand thread direction (counter-clockwise). Pay attention to even pressure and avoid tilting.
5. Completion and cleaning: When the thread has reached the desired depth, carefully turn the tap back. Thoroughly clean the cut thread and the tap of chips and residues.

• Thread Type: American tapered pipe thread, taper 1:16
• Standard: DIN 374
• Form: Form C
• Material: HSS-G
• Nominal Size: NPT 1/8 x 27
• Overall Length (L1): 65 mm
• Thread Length (L2): 19 mm
• Shank Diameter (D2): 7 mm
• Drive Square: 5.5 mm
• EAN: 4022835630029
• Article Number: 63002

Q1: What is a left-hand thread and what is it used for?

A1: A left-hand thread is tightened counter-clockwise and loosened clockwise. It is used in applications where a right-hand thread would unintentionally loosen due to rotation or vibrations. A well-known example is the left pedal on bicycles. For more information on left-hand threads, see this video: Left Hand Threads explained.

Q2: What is an NPT thread and how is it different?

A2: NPT stands for "National Pipe Taper" and refers to an American tapered pipe thread with a taper ratio of 1:16. This tapered shape ensures that the thread flanks press tightly into each other when screwed in, creating a pressure-tight connection without additional sealing agents (like sealing tape or hemp). This distinguishes it from straight pipe threads (e.g., NPS) that often require a separate seal.

Q3: For which materials is this tap suitable?

A3: This HSS-G tap is designed for well-machinable materials with a tensile strength up to 900 N/mm². This includes unalloyed and low-alloyed steels, which are commonly used in plumbing and mechanical engineering.

Q4: What does Form C mean for this tap?

A4: Form C refers to the lead of the tap, which is about 2 to 3 threads. This short lead form is versatile and works well for both through and blind holes.

Q5: Can this tap be used for both manual and machine use?

A5: Yes, this single-pass tap is suitable for both manual use with a tap wrench and for machine use in appropriate tapping machines. Its robust HSS-G construction supports both application types.

Q6: Why is the HSS-G material designation important?

A6: HSS-G stands for "High Speed Steel - Ground." This material offers high hardness and wear resistance, ensuring a long tool life. The ground finish of the cutting edges also provides high precision and a good surface quality of the cut thread.

Q7: What advantages do tapered pipe threads like NPT offer?

A7: The main advantage of tapered pipe threads is their self-sealing property. The tight pressing of the thread flanks creates a sealed connection, which is particularly beneficial for gas and fluid lines. This reduces the need for additional sealing materials and simplifies assembly.