# Thread Pitch Gauge: Tap Drill — Machinist RPM & Bolt Circle

> Machinist RPM & Bolt Circle (iPhone/iPad app by Vladislav Zhirnov.)

- Source: https://appshunter.io/ios/app/thread-pitch-gauge-tap-drill/id6761341851 (this page in markdown: same URL + `.md`)
- Developer: [Vladislav Zhirnov](https://appshunter.io/developer/1476188065)
- Category: Utilities, Productivity
- Price: $1.99
- Age rating: 4+
- Requires: iOS 17.0 · 6 MB
- Languages: American English, Arabic, Croatian, Czech, Danish, Dutch, Finnish, French (France), German (Germany), Greek and 22 more
- Released: 2026-04-01
- Data updated: 2026-09-05
- User reviews in markdown: https://appshunter.io/ios/app/thread-pitch-gauge-tap-drill/id6761341851/reviews.md

## What is Thread Pitch Gauge?

Turn your iPhone or iPad into a calibrated thread gauge and practical machining toolkit.

Thread Pitch Gauge helps machinists, CNC operators, mechanics, fabricators, and serious DIY users identify fasteners, choose drills, calculate layouts, and create shop-ready templates—right at the machine.

MEASURE & IDENTIFY
• Match an unknown thread with an on-screen pitch gauge.
• Measure diameter with the virtual caliper.
• Use the guided thread wizard and reference tables for ISO Metric, UNC, UNF, UNEF, NPT, BSPT, and SAE machine-screw standards.
• Find tap drills, clearance holes, drill sizes, and metric/inch equivalents.
• Create and save custom thread entries.

MACHINING & LAYOUT CALCULATORS
• Surface Speed / RPM / Diameter
• Bolt Circle / PCD with X/Y coordinates, start angle, and CW/CCW direction
• Single-row and variable-diameter hole spacing
• Rectangular, circular, and oval hole patterns
• Right Triangle calculations
• Diameter Tape
• Dividing Plate layouts

SAVE, PRINT & SHARE
Keep important calculations with names and notes, then export PDF reports, CSV coordinate tables, or SVG drawings. Generate true-size Diameter Tape and Dividing Plate templates where supported.

BUILT FOR REAL SHOP WORK
• Switch between metric and imperial units.
• Works offline—no account required.
• Localized for 33 languages.
• Designed for iPhone and iPad.

FREE TO PREVIEW
Download free and preview every feature. A single Full Access purchase unlocks all calculations, interactive controls, saving, and export forever. No subscription.

Whether you are identifying a mystery bolt, setting spindle RPM, laying out a flange, or preparing a drilling template, Thread Pitch Gauge replaces scattered charts and single-purpose calculators with one fast, organized shop companion.

Important: Calibrate on-screen measuring tools before use. Printed template accuracy depends on printer scaling. Always verify critical dimensions and machining parameters before cutting.


## Version history (last 2 releases)

### 2 — 2026-09-01

Version 2.0 is our biggest update yet:

• 9 new machining and hole-layout calculators
• PDF, CSV, and SVG export
• Saved calculations and true-size templates
• Metric and imperial support
• Improved interface, stability, and localization

The app is now free to preview with a one-time Full Access unlock. Existing version 1.x customers keep full access.

### 1.0 — 2026-04-01

No release notes.

## More apps by Vladislav Zhirnov

- [Facefitness - face exercise](https://appshunter.io/ios/app/facefitness-face-exercise/id1476188216)
- [Neon Bleep Test PRO](https://appshunter.io/ios/app/neon-bleep-test-pro/id1487695486)
- [Ideas fast log](https://appshunter.io/ios/app/ideas-fast-log/id1491519557)
- [Concentrate and guess color](https://appshunter.io/ios/app/concentrate-and-guess-color/id1491661397)
- [Postage stamps: all countries](https://appshunter.io/ios/app/postage-stamps-all-countries/id1497958107)
- [Road signs: all countries](https://appshunter.io/ios/app/road-signs-all-countries/id1500810663)

All apps by Vladislav Zhirnov: https://appshunter.io/developer/1476188065

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-05.*