ThreadChaser

Screw Thread Identifier

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

Internal / External Thread Identifier ThreadChaser is the fastest way to identify an unknown thread — on the shop floor, in the field, or at the workbench. Simply measure the major diameter and pitch of any fastener or threaded component, enter the values, and ThreadChaser instantly searches its database of metric and imperial thread standards to find the closest matches. No more guessing, no more flicking through reference books, no more ordering the wrong tap or die. Who it's for ThreadChaser is built for engineers, machinists, mechanics, maintenance technicians, and anyone who regularly works with threaded fasteners. Whether you're identifying a mystery bolt on a piece of imported machinery, matching a thread on a worn component, or specifying a tap drill size for a new hole, ThreadChaser gives you the answer in seconds. What it covers: ISO Metric coarse and fine threads (M1 through M68) Unified National threads — UNC, UNF, and UNEF British Standard — BSW, BSF, and BSP With more standards being added regularly What you get: Instant thread matching with a tolerance you control Pitch diameter and minor diameter for every result Recommended tapping drill sizes Internal and external thread modes Technical thread profile diagrams A full reference library of thread standards and formulas How to use: Use a digital calliper to measure the major diameter or internal bore of the thread. Use a thread pitch gauge or ruler to measure the pitch (distance between thread crests). Enter both values, select your preferred standards, and hit Search. ThreadChaser ranks every match by how closely it fits your measurement. Terms of Use: https://www.threadchaser.com/TERMS

  • This app hasn’t received enough ratings or reviews to display an overview.

Fixed a bug that stops thread diagrams rendering in Dark Mode

The developer, JAMIE SAM PARTOVI, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Seller
    • JAMIE SAM PARTOVI
    Size
    • 1.6 MB
    Category
    • Utilities
    Compatibility
    Requires iOS 18.6 or later.
    • iPhone
      Requires iOS 18.6 or later.
    • iPad
      Requires iPadOS 18.6 or later.
    • Mac
      Requires macOS 15.6 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 2.6 or later.
    Languages
    • English
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    • © 2026 Jamie Partovi