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Wiseman Threading Tools Spiral Flute Metric HSS Tap Left Hand - M20x2.5
| Thread Form | Metric |
| Size | M20 |
| Pitch | 2.5 |
| Tap Type | Spiral Flute Tap |
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Description

Meet the Wiseman Threading Tools Spiral Flute Metric HSS Tap Left Hand - M20x2.5, a purpose-built tapping solution for metalworking that demands precision, control, and reliability. This uncoated high-speed steel tap is ground for accurate thread formation and smooth operation, with ISO 529 dimensions that you can trust in daily production and workshop use.
Designed for left-hand applications, this tap cuts threads in the opposite direction, making it ideal for assembling reverse-threaded components, fixtures that require anti-backout threads, or situations where a left-handed fastener is part of the engineered design. The spiral flute geometry enhances chip evacuation and reduces the risk of binding in through-holes or deep blind holes, delivering cleaner threads and less tapping effort over long runs.
- : Specifically shaped to create or repair left-handed threads with consistent depth and pitch.
- Spiral flute design: Optimizes chip removal for smoother tapping and reduced clogging in harder or longer holes.
- Metric accuracy: M20x2.5 thread profile aligned with ISO 529 standards for reliable fit with corresponding fasteners and components.
- Material and finish: High-speed steel ground for a sharp, durable cutting edge; uncoated for broad compatibility with a range of metals and lubrication regimes.
- General-purpose versatility: A go-to tap in automotive, fabrication, maintenance, and workshop settings where left-hand threads or reverse-threaded assemblies are required.
How this tap performs in real-world tasks:
- Removing stubborn or reverse-acting fasteners where a left-hand thread is essential, without damaging surrounding material.
- Creating precise left-hand threads in steel, alloy, or similar metals where conventional right-hand taps aren’t suitable.
- In production or maintenance environments where fast, reliable threading is needed for repeatable results and easier disassembly when required.
Practical tips for optimal results:
- Use a compatible tapping fluid or lightweight cutting oil to reduce friction and extend tool life.
- Secure the workpiece firmly and start the cut with steady, moderate pressure while turning counterclockwise to maintain straight, true threads.
- When depth is reached, back off slightly to break chips, then withdraw the tap cleanly to inspect the new threads.
- Match the drill/tapping setup to the M20x2.5 specification—typical tapping drill sizes are around 17.5 mm, but confirm with your material and tooling guidelines.
Invest in the Wiseman tapping solution to achieve dependable left-handed threads with clear geometry, durable cutting edges, and a design that keeps your workflow moving—whether you’re outfitting a machine shop, a maintenance bench, or a fabrication station.
Part Numbers
- Protool Part Number
- T14857SFLH
- Brand
- Wiseman
- Category
- Hand Tap
Delivery
Free UK mainland delivery on orders over £50 ex VAT. In-stock items ordered before 4:30pm are dispatched the same working day. Full delivery information.
Returns
14-day returns on unused stock items in original packaging. Special-order and bespoke tooling is non-returnable. Read our returns policy.
Technical Support
Over 30 years of machining experience behind the counter. Call 01732 887334, Mon–Thurs 8:30–17:30, Fri 8:30–16:30.
Trade Accounts
Credit accounts, contract pricing and scheduled call-off orders available for trade customers. Apply for an account.
What time are Protool open?
We are open Monday to Friday between 8:30am and 5pm.
Do you offer Free Next Day delivery?
Yes! We offer Free Next Day delivery via Royal Mail Tracked 24 on all orders over £50 ex VAT*. We also offer Free DPD Local Next Day delivery on all orders over £100 ex VAT*.
We also offer the following:
- Royal Mail Tracked 24 — £5.90 (FREE on orders over £50 ex VAT*). Order before 4:30pm for next day delivery. No signature required.
- DPD Local Next Day — £8.00 (FREE on orders over £100 ex VAT*). Standard next day delivery to UK mainland addresses.
- Royal Mail Special Delivery — £12.50. Guaranteed delivery before 1pm the next working day.
- DPD Saturday Delivery — £25.00. Must be ordered on Friday before 4pm. Pre-12pm delivery.
For delivery to Scottish Highlands & Islands, Northern Ireland, Republic of Ireland, or overseas locations, additional charges apply. Please see our delivery page for full details, or call us on 01732 887 334.
*T's & C's and exclusions apply. Please see our delivery page for more information on all our services.
Full Range: Wiseman Threading Tools Spiral Flute Metric HSS Taps Left Hand
View full collection →You are viewing T14857SFLH. Click any other SKU to view its full details.
| Product SKU | Thread Form | Size | Pitch | Tap Type | Thread Direction | Price | Stock | Order |
|---|---|---|---|---|---|---|---|---|
| T10857SFLH | Metric | M4 | 0.7 | Spiral Flute Tap | Left Hand | £18.57 | 1-2 days | |
| T11157SFLH | Metric | M5 | 0.8 | Spiral Flute Tap | Left Hand | £18.57 | 1-2 days | |
| T11407SFLH | Metric | M6 | 1 | Spiral Flute Tap | Left Hand | £18.57 | 1-2 days | |
| T11907SFLH | Metric | M8 | 1.25 | Spiral Flute Tap | Left Hand | £22.85 | 1-2 days | |
| T12457SFLH | Metric | M10 | 1.25 | Spiral Flute Tap | Left Hand | £40.14 | 1-2 days | |
| T12507SFLH | Metric | M10 | 1.5 | Spiral Flute Tap | Left Hand | £29.13 | 1-2 days | |
| T13107SFLH | Metric | M12 | 1.75 | Spiral Flute Tap | Left Hand | £37.07 | 1-2 days | |
| T14007SFLH | Metric | M16 | 1.5 | Spiral Flute Tap | Left Hand | £67.02 | 1-2 days | |
| T14107SFLH | Metric | M16 | 2 | Spiral Flute Tap | Left Hand | £45.72 | 1-2 days | |
| T14407SFLH | Metric | M18 | 1.5 | Spiral Flute Tap | Left Hand | £70.02 | 1-2 days | |
| T14757SFLH | Metric | M20 | 1.5 | Spiral Flute Tap | Left Hand | £76.34 | 1-2 days | |
| T14857SFLH Viewing | Metric | M20 | 2.5 | Spiral Flute Tap | Left Hand | £67.58 | 1-2 days | |
| T15657SFLH | Metric | M24 | 3 | Spiral Flute Tap | Left Hand | £87.36 | 1-2 days |
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