Hand Tap Bottoming ISO 529 Form C HSS-G - UNF 1.3/8 x 12

• for manual internal thread cutting as the bottoming stage of the hand tap sequence
• for UNF 1.3/8 x 12 when the thread system and pitch match the workpiece
• for maintenance, tool room, field service, and repair work with a suitable tap wrench
• for finishing closer to the bottom of blind holes after suitable preparation
• 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 hand tap stage in the correct sequence and match all follow-up taps to the same thread designation.

• The bottoming stage gives a defined role inside the manual hand tap sequence.
• HSS-G material is stated in the product data and supports precise hand tapping in suitable materials.
• The designation UNF 1.3/8 x 12 helps distinguish similar inch or pipe thread variants.
• Manual operation gives the user direct control over alignment and cutting resistance.

• A single hand tap stage may not complete every hand tapping process, so use matching stages from the same thread size where required.

1. Check that UNF 1.3/8 x 12 matches the drawing or the existing thread.
2. Prepare the hole and chamfer according to the hand tapping process.
3. Clamp the hand tap in a suitable tap wrench.
4. Apply cutting fluid suited to the workpiece material.
5. Start the bottoming hand tap square to the hole axis.
6. Turn with controlled pressure and reverse carefully to clear chips.
7. Clean the hole before moving to the next matching hand tap stage if required.
8. Inspect the internal thread before assembly.

• 1 piece Hand Tap Bottoming ISO 529 Form C HSS-G - UNF 1.3/8 x 12

• Product type: hand tap bottoming
• Thread system: UNF
• Thread designation: UNF 1.3/8 x 12
• Standard: ISO 529
• Material: HSS-G
• Tap form: C
• Direction: RH

Where does this tap fit in the hand tapping sequence?

It is the bottoming stage, so use it at the correct point in the manual tapping process.

How do you select the correct thread?

Match UNF 1.3/8 x 12 exactly to the component or drawing, including direction when left-hand thread is stated.

Can this single hand tap replace the full sequence?

Not always, because a complete hand tapping process can require matching stages from the same thread size.

What holder do you need?

Use a suitable tap wrench that holds the square securely and allows straight manual alignment.

What should you check before starting?

Check the drilled hole, chamfer, thread direction, and lubrication before applying torque.

Where can you find hand tap information?

Additional hand tap information is available here: Technical information hand taps as PDF

Where can you find the threading tools catalog?

You can find the threading tools catalog here: VD 23 catalog as PDF