Buy Screw Pitch Gauges Online in Australia
Screw Pitch Gauge Range — Quick Reference
Screw pitch gauges are leaf-style gauges for identifying thread pitch on unknown screws, bolts and fittings. Run each leaf across the thread until you find the one that seats perfectly with no rocking or gap — that's your pitch. Critical for matching replacement fasteners, selecting correct taps, and confirming fitting compatibility. AIMS stocks gauges across all common Australian thread standards.
| Gauge Type | Pitch Range | Best For Identifying |
|---|---|---|
| ISO Metric Pitch Gauge | 0.25 - 6.0 mm pitch | Metric coarse + fine threads (workshop default for AU + EU equipment) |
| UNC / UNF (Imperial) Pitch Gauge | 4 - 80 TPI (threads per inch) | US-origin machinery, automotive imports, older equipment |
| BSP / Whitworth Pitch Gauge | 4 - 60 TPI | Pipe threads, older Australian/UK machinery, vintage equipment |
| Combined Metric + Imperial | Both ranges in one tool | General workshop use — covers most fastener identification needs |
| Multi-Pitch (Metric + UNC + UNF + BSP) | Comprehensive single tool | Mixed-standard workshops, mobile maintenance crews |
How to use: seat the gauge leaf into the thread peaks; if the leaf rocks or shows gaps between teeth, try the next pitch. The correct gauge will sit flat with all teeth engaged. For matching taps once pitch is identified, see taps. For thread chasing on damaged external threads, see die nuts. For broader background, see our threading tap size chart.
Screw Pitch Gauges for Thread Identification in Australian Workshops
Screw pitch gauges are the precision-formed leaf gauges used to identify thread pitch on screws, bolts, and threaded components. For Australian fitters, mechanics, and toolroom workers handling unidentified or replacement threaded components, a pitch gauge is the fastest path to confirming the right thread for replacement, matching tap, or compatible fitting. AIMS Industrial stocks screw pitch gauges across metric, imperial, and pipe thread standards.
The pitch gauge types we stock
- ISO metric pitch gauges — for metric coarse and fine pitches (the everyday workshop standard)
- UN/UNF/UNC pitch gauges — for American imperial threads
- BSW (Whitworth) pitch gauges — for British heritage imperial threads
- BSP/BSPT pitch gauges — for pipe threads
- Combination gauges — multiple thread standards on one fan-handle gauge
How pitch gauges work
Each leaf in the gauge has a precision-formed thread profile matching a specific pitch. To identify a thread, place the gauge against the thread and check for full engagement — the gauge profile should mate cleanly with the thread crests and roots, with no visible gap. The matching pitch is the one printed on that leaf. For external threads, place the gauge over the threads; for internal threads (in tapped holes), use small-tip gauges that fit into the bore.
Where pitch gauges earn their place
- Thread identification on unmarked components — confirming the pitch of a threaded shaft, fastener, or fitting
- Replacement fastener sourcing — confirming the existing thread before ordering replacements
- Tap selection — verifying the tapping drill and tap size for thread cutting
- Cross-reference between thread standards — checking whether a thread is metric, UN, BSW, or BSP
- Quality control — verifying threads on production parts
Common thread standards in Australian workshops
- ISO metric coarse — the dominant standard in modern Australian engineering and manufacturing
- ISO metric fine — used in specific high-stress and precision applications
- UNC and UNF — common in US-origin equipment, automotive, and aerospace
- BSW (Whitworth) — heritage British equipment, restoration work, older machinery
- BSP and BSPT — Australian plumbing and hydraulic threads
- NPT — US pipe threads, found in imported plumbing and pneumatic equipment
Care and accuracy
Pitch gauges are precision tools. Store them in their case or roll, keep clean and lightly oiled to prevent rust, and inspect leaf edges before relying on the readings. Damaged or bent leaves give false readings. For traceable inspection workplaces, periodic calibration may be required as part of the broader measuring tool calibration regime.
Companion ranges at AIMS
Screw pitch gauges sit alongside our broader measuring tools range — see measuring tools, radius gauges, metric hand taps, and protractors for the related products.
Need help matching pitch gauges to specific thread standards or workshop work? contact our team — we'll match by thread system and resolution.
People Also Ask — Screw Pitch Gauges
Q: What does a screw pitch gauge measure?
It measures the thread pitch — the distance between adjacent thread crests — to identify what thread system and pitch a fastener uses. The gauge has leaves with teeth matching standard thread pitches; the leaf that matches the thread profile cleanly identifies the pitch. From there you can determine whether the thread is metric coarse, metric fine, UNC, UNF, BSP, NPT, or another system.
Q: Do I need separate metric and imperial pitch gauges?
Yes — they measure different units. Metric pitch gauges read in millimetres (1.0mm, 1.25mm, 1.5mm, 1.75mm etc) and identify metric thread pitches directly. Imperial pitch gauges read in threads per inch (TPI) — 11, 12, 14, 16, 18, 20 etc. A workshop dealing with both metric and imperial work needs both gauges. Combination sets are available with both scales on the same tool.
Q: How do I use a pitch gauge correctly?
Try leaves until one drops cleanly between the threads with no gap and no rocking. The matched leaf indicates the pitch. If multiple leaves seem to fit, try them on a longer section of thread — the truly correct pitch will track several adjacent threads consistently. Don't force a leaf into the threads; if it doesn't slide in cleanly, it's the wrong pitch.
Q: Can a pitch gauge identify the thread diameter?
No — only the pitch. For the full thread spec you also need to measure the major diameter (outside diameter of the bolt thread, or hole diameter for internal threads) with calipers. Pitch + diameter together identify the thread (e.g. 1.25mm pitch + 8mm diameter = M8 x 1.25 metric coarse). Most thread reference charts cross-reference pitch and diameter to standardised thread designations.
Q: What pitch gauges should be in a workshop kit?
A combination metric and imperial pitch gauge covering the standard pitches in each system handles 90+ percent of workshop identification work. For specialty work add a BSP/NPT pipe thread pitch gauge — pipe threads have different angle and pitch conventions than fastener threads. Threaded fasteners measured with a pipe gauge (or vice versa) won't read correctly.