Hand Tap Second ISO 529 Form D HSS-G - UNF No. 6 x 40

• Cut UNF internal threads in drilled holes where a controlled manual tapping process is required.
• Use Form D second chamfer after the starting operation when the thread must be guided toward full profile depth.
• Match the UNF No. 6 x 40 designation to the drawing, mating screw, and required right hand thread before machining.
• Use a tap wrench or guided hand tapping setup to keep the tool square to the hole axis.
• Prepare the core hole according to the stated 3 mm drilling value before starting the thread.
• Process: manual driving or assisted driving depending on your holder and machine setup
• Use: thread cutting, re tapping, and thread cleaning depending on condition

Note Use the second tap after the thread entry is started, keep the tap aligned, and stop if torque rises suddenly.

• ISO 529 design reference supports clear identification of the hand tap family in drawings and product data.
• Form D second geometry supports a staged hand tapping sequence between starting and finishing operations.
• HSS-G execution links the tool choice to ground high speed steel rather than an unspecified cutting material.
• Tolerance class 2B helps align the tapped internal thread with the required fit class.
• The stated core hole diameter gives a direct preparation value for drilling before tapping.

• Manual tapping depends on operator alignment, so tilted entry can damage the internal thread.
• The tool is not a replacement for a guided machine tapping process when repeatability, feed control, or coolant delivery must be validated.

1. Match the complete UNF No. 6 x 40 thread designation, direction, and tolerance requirement with the drawing or mating part.
2. Prepare the core hole according to the documented drilling data.
3. Chamfer the hole entry to support centred starting.
4. Mount the hand tap in a suitable tap wrench.
5. Align the hand tap square to the hole axis.
6. Apply cutting fluid that fits the work material.
7. Start the cut with steady torque and controlled feed.
8. Reverse briefly at intervals to clear chips from the flutes.
9. Withdraw the tool carefully after the required thread depth is reached.

• 1 piece Hand Tap Second ISO 529 Form D HSS-G - UNF No. 6 x 40

• Product type: Hand tap
• Tap stage: Second
• Standard: ISO 529
• Chamfer form: Form D
• Flute form code: N
• Thread system: UNF
• Thread size: UNF No. 6 x 40
• Thread standard: ANSI B 1.1
• Thread direction: Right hand thread
• Tolerance class: 2B
• Tool material or execution: HSS-G
• Overall length L1: 50 mm
• Thread length L2: 13 mm
• Shank diameter D2: 3.55 mm
• Square drive k: 2.8 mm
• Core hole diameter: 3 mm
• Packaging unit: 1 piece

How do you confirm that this hand tap matches the required thread?

Match the full UNF No. 6 x 40 designation, right hand thread, tolerance class 2B, and thread standard ANSI B 1.1 against the drawing or mating part before you cut.

What does UNF mean in the thread designation?

UNF denotes Unified National Fine, an inch based thread series used when a finer inch pitch is specified by the part drawing or mating fastener.

Where can you find detailed technical notes for hand taps?

Technical information hand taps as PDF

When do you use a second hand tap in the tapping sequence?

A Form D second hand tap is used after the thread has been started, so the profile can be developed further with controlled guidance.

Where can you find an inch to millimetre reference for UNF work?

Inch to mm conversion table as PDF

What is important when working with left hand inch threads?

Use a left hand tap only when the part drawing specifies LH or the mating fastener has a reverse tightening direction. A right hand tap would cut the wrong thread direction.

Where can you find catalog information for this threading tool?

VD 23 catalog as PDF

How do you reduce the risk of tap breakage during manual use?

Keep the tool aligned, use cutting fluid, avoid side load, and clear chips before torque becomes excessive.