Tap Drill Size Chart — Free Online Tool
Pilot hole size for any tap thread
Find correct drill bit for any tap. Metric + imperial. 75% and 50% thread engagement.
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Tap drill size calculator
Find the correct drill bit for any tap. UNC, UNF, metric.
How to use this tool
- 1
Pick tap size
Select from standard UNC/UNF/metric.
- 2
Pick thread engagement %
75% standard; 50% for hard materials.
- 3
See drill size
Exact + closest standard bit.
Frequently Asked Questions
Why 75% thread engagement?
Standard engagement. Gives 95% of thread strength but 66% of the drilling effort vs 100%. Industry default for most jobs.
When to use 50%?
Hardened steels, stainless, or when breaking taps is a concern. Weaker threads but much easier tapping.
Key Takeaways
- Tap Drill Size Chart is a free, browser-based calculator tool — pilot hole size for any tap thread.
- No signup, no downloads, no file uploads — your data stays on your device.
- Works on desktop, tablet, and mobile. Install as a PWA for offline access.
How to Use Tap Drill Size Chart
- Open the tool: Launch Tap Drill Size Chart on Toololis — no account or download needed.
- Enter your data: Paste text, enter values, or select a file directly in your browser.
- Get instant results: Everything is processed locally — results appear immediately.
- Copy or download: Save your output or share it. Bookmark for quick access next time.
Tap Drill Size Chart — Quick Facts
- Price
- Free — no limits, no watermarks, no paywalls
- Privacy
- 100% browser-based — no data is sent to any server
- Platform
- Any modern browser on desktop, tablet, or mobile
- Category
- Calculator Tools on Toololis
- Offline
- Works offline after first visit (Progressive Web App)
| Feature | Details |
|---|---|
| Tool | Tap Drill Size Chart |
| Category | Calculator |
| Signup Required | No |
| File Upload | None — processed in browser |
| Mobile Support | Fully responsive |
| Cost | Free forever |
Why Use Tap Drill Size Chart?
You should try Tap Drill Size Chart for a quick, private way to pilot hole size for any tap thread. All processing happens in your browser. Your files and data never leave your device. According to web.dev, client-side processing is the gold standard for privacy.
On the other hand, dedicated APIs or desktop tools suit batch processing better. They also handle server-side automation. For everyday tasks, browser tools offer the best speed, privacy, and convenience.
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100% Privacy. This tool runs entirely in your browser. Your data is never uploaded to any server.