GY HHT HSS Ground Thread Hand Taps

HSS Hand Taps (Serial and Non-Serial Form)
Coarse Pitch & Fine Pitch
As per IS:6175 Part 2 & ISO 529

Our High-Speed Steel (HSS) Hand Taps are engineered for precision internal threading in a wide range of materials. Manufactured in strict accordance with IS: 6175 (Part 2) standard, these tools ensure dimensional accuracy and long-lasting performance for both manual and machine-assisted tapping operations.

Serial Form Hand Taps

Serial taps are designed to distribute the cutting load across three distinct stages. In this set, each tap has a different diameter, allowing for a progressive “roughing to finishing” process that reduces the torque required and minimizes the risk of tap breakage in hard materials.
  • No. 1 (Rougher): Features a long 6-8 thread lead. It does the bulk of the material removal and establishes the initial thread path.
  • No. 2 (Intermediate): Features a 4-5 thread lead. It deepens the threads and brings them closer to the final size.
  • No. 3 (Finisher): Features a short 2-3 thread lead. It cuts the thread to its final tolerance and allows for threading closer to the bottom of a hole.

Non-Serial Form Hand Taps

Non-serial taps (Standard Sets) all share the same full thread diameter but vary in the length of the chamfer (the tapered lead at the tip). These are ideal for general-purpose applications.
  • No. 1 – Form A (Taper): Longest chamfer (6-8 threads). Used to start the threading process, ensuring easy alignment and a gradual cut.
  • No. 2 – Form D (Second/Plug): Medium chamfer (4-5 threads). The most commonly used tap for through-holes or starting blind holes.
  • No. 3 – Form C (Bottoming): Shortest chamfer (2-3 threads). Essential for threading to the very bottom of blind holes where space is limited.

Key Features

  • Standard Compliance: Produced as per IS: 6175 Part 2 and International specifications for global compatibility.
  • Class of Tolerance:Produced as per 6H. When the screwing tap is desired for class of tolerance other than 6H, class of tolerance 4H or 7H or 7H cut threads as appropriate, shall be mentioned in the designation immediately after the size.
  • Material: Premium Grade High-Speed Steel (HSS) for superior heat resistance and edge retention.
  • Flute Design: Precision-ground straight flutes provide ample space for chip evacuation and lubricant flow.
  • Application: Suitable for alloy steel, carbon steel, cast iron, and non-ferrous materials.
Unless otherwise specified No. 2 – Form D non-serial screwing tap shall be supplied. For sets please mention serial or non serial sets required.
Note: For optimal tool life and thread quality, always use appropriate cutting oil and ensure the pre-drilled hole size matches the recommended tap drill chart.
TECHNICAL SPECIFICATION FOR COARSE PITCH
Size (mm) Nominal Dia (D) Pitch d (h9) l L d1 (Min) l1 Square a (h11) Square l2
M 3 x 0.5 3 0.5 3.15 11 48 2.12 7 2.5 5
M 3.5 x 0.6 3.5 0.6 3.55 13 50 2.5 7 2.8 5
M 4 x 0.7 4 0.7 4 13 53 2.8 8 3.15 6
M 4.5 x 0.75 4.5 0.75 4.5 13 53 3.15 8 3.55 6
M 5 x 0.8 5 0.8 5 16 58 3.55 9 4 7
M 6 x 1 6 1 6.3 19 66 4.5 11 5 8
M 7 x 1 7 1 7.1 19 66 5.3 11 5.6 8
M 8 x 1.25 8 1.25 8 22 72 6 13 6.3 9
M 9 x 1.25 9 1.25 9 22 72 7.1 14 7.1 10
M 10 x 1.5 10 1.5 10 24 80 7.5 15 8 11
technical specification FOR fine pitch
size (mm) Nominal Dia (D) Pitch d (h9) I L d1 (Min) I1 Square a (h11) Square l2
M 3 × 0.35 3 0.35 3.15 11 48 2.12 7 2.5 5
M 3.5 × 0.35 3.5 0.35 3.55 13 50 2.5 7 2.8 5
M 4 × 0.5 4 0.5 4 13 53 2.8 8 3.15 6
M 4.5 × 0.5 4.5 0.5 4.5 13 53 3.15 8 3.55 6
M 5 × 0.5 5 0.5 5 16 58 3.55 9 4 7
M 5.5 × 0.5 5.5 0.5 5.6 17 62 4 9 4.5 7
M 6 × 0.75 6 0.75 6.3 19 66 4.5 11 5 8
M 7 × 0.75 7 0.75 7.1 19 66 5.3 11 5.6 8
M 8 × 0.75 8 0.75 8 16 66 6 13 6.3 9
M 8 × 1 8 1 8 19 69 6 13 6.3 9
M 9 × 0.75 9 0.75 9 16 66 7.1 14 7.1 10
M 9 × 1 9 1 9 19 69 7.1 14 7.1 10
M 10 × 0.75 10 0.75 10 17 73 7.5 15 8 11
M 10 × 1 10 1 10 20 76 7.5 15 8 11
M 10 × 1.25 10 1.25 10 20 76 7.5 15 8 11