STI Hand Tap ISO 529 HSS-G - M 42 x 3

• for general use
• for easily machinable materials up to 900 N/mm²
• for unalloyed and low-alloy steels
• for manual use
• for STI receiving threads in size M 42 x 3
• for repair processes with a specified 42.90 mm core hole
• for controlled repairs on large internal threads with a finer pitch
• for maintenance, workshop use, plant service and single-part repair
• for applications where the finer pitch supports controlled thread guidance

Note: This tap creates the STI receiving thread, not the final working thread in the component. For M 42 x 3, the 42.90 mm core hole, 3.0 mm pitch and thread insert system must be checked together. Matching components can be found in the VÖLKEL thread repair range.

• designed specifically for M 42 x 3 instead of being a standard tap
• clear process data with 42.90 mm core hole, 45.9 mm B dimension and ISO1 (4H)
• HSS-G design for general use in easily machinable materials
• hand guidance makes controlled starting easier on large diameters
• well suited for individual thread repairs rather than series production
• the finer pitch supports calm and precise repair work

• STI tools must match the insert system precisely; if insert length or material strength is unclear, choose a suitable VÖLKEL thread repair solution before machining

1. Inspect the damaged thread and make sure the surrounding material is still suitable for repair.
2. Drill or check the core hole for M 42 x 3 to 42.90 mm.
3. Deburr the bore and remove chips so that the hand tap can start cleanly.
4. Align the STI hand tap square to the bore and use a suitable tap wrench.
5. Apply cutting lubricant and start the first turns without side load.
6. Cut with steady movements and break chips regularly by reversing briefly.
7. Check the usable thread depth with the 45.000 mm thread length in mind.
8. Clean and inspect the receiving thread before installing the matching wire thread insert.

• 1x STI Hand Tap ISO 529 HSS-G - M 42 x 3

• Article number: 03068
• Product type: STI hand tap for receiving threads
• Type category: HGB
• Type: S2
• Standard reference: ISO 529
• Material: HSS-G
• Thread type: STI-M
• Nominal size: M 42 x 3
• Pitch: 3.0 mm
• Thread direction: RH
• Thread standard: DIN 13
• Tolerance: ISO1 (4H)
• B dimension: 45.9 mm
• Core hole diameter: 42.90 mm
• Overall length L1: 165.000 mm
• Thread length L2: 45.000 mm
• Shank diameter D2: 31.500 mm
• Square k: 28.000 mm
• Bore: DSLO
• Packaging unit: 1
• GTIN: 4022835030683

What is different from a standard M 42 x 3 tap?

This tool cuts the STI receiving thread for a wire thread insert. The final working thread is created by the insert, so it must not be used like a standard M 42 x 3 tap.

Which core hole is specified?

Article 03068 specifies a core hole diameter of 42.90 mm. This value must match the insert system and the required repair depth.

Why is hand tapping useful for large repairs?

With large diameters, torque and alignment have a stronger influence on the result. Manual guidance gives better control over starting, chip breaking and cutting progress.

Which materials are suitable for this HSS-G version?

It is intended for general use in easily machinable materials up to 900 N/mm², especially unalloyed and low-alloy steels.

What should be checked before fitting the insert?

Check that the receiving thread, 42.90 mm core hole, thread depth and insert system fit together. The thread should be clean, chip-free and correctly aligned.

Where can matching system components be found?

Matching inserts, tools and accessories are available in the VÖLKEL thread repair range.