Screw Pitch Gauges

About Screw Pitch Gauges

Screw pitch gauges are precision measuring tools designed to quickly and accurately identify the pitch and thread type of screws, bolts, and threaded fasteners. Consisting of multiple thin metal blades stamped with specific thread profiles that fold into a compact handle, these gauges allow tradespeople to instantly determine whether a thread is metric, imperial, BSW (British Standard Whitworth), UNC (Unified National Coarse), UNF (Unified National Fine), or another thread standard. MyToolShed.co.uk stocks screw pitch gauges from trusted brands including Sealey, Draper, and Faithfull, with sets ranging from 20 to 55 blades to cover the most commonly encountered thread pitches.

These essential workshop tools are manufactured from hardened steel for durability and long-term accuracy, with clearly marked measurements typically ranging from 0.25mm to 6mm for metric threads, and various TPI (threads per inch) ranges for imperial standards. Whether you need a compact metric-only gauge for general workshop use or a comprehensive 52-piece set covering multiple thread standards for specialist engineering work, MyToolShed offers options suited to both professional tradespeople and serious DIY enthusiasts working with older machinery, imported equipment, or legacy fasteners.

Applications

Screw pitch gauges are indispensable tools across numerous trades and industries:

• Mechanical Engineers – identifying threads on machinery components, hydraulic fittings, and precision equipment
• Motor Vehicle Technicians – determining fastener specifications on vehicles, particularly classic cars or imported models
• Maintenance Engineers – sourcing correct replacement fasteners for plant machinery and production equipment
• Plant Fitters – matching threads on pipework, valves, and industrial equipment during installation and repair
• Agricultural Mechanics – identifying fasteners on farm machinery with various thread standards
• CNC Machinists – verifying thread specifications during manufacturing and quality control processes
• Plumbers – identifying threads on pipe fittings when working with mixed metric and imperial systems
• General Maintenance Staff – determining correct replacement fasteners across facilities management
• DIY Enthusiasts – particularly those restoring machinery, vehicles, or working with older equipment

Choosing The Right Screw Pitch Gauges

Thread Standards Required: Consider which thread systems you encounter most frequently. A basic metric-only gauge like the Sealey 20-blade folding gauge suits general workshop applications, whilst engineers working with diverse equipment may need comprehensive sets covering metric, BSW, UNC, UNF, and other standards. The Faithfull 55-blade American-National set or Draper 52-blade combination sets provide extensive coverage for professional environments.

Number of Blades: More blades mean finer increments and better chance of finding an exact match. A 20-blade set covers common pitches adequately for general use, whilst 52-55 blade sets provide comprehensive coverage including less common thread pitches found on specialist or imported equipment.

Build Quality: Professional-grade gauges from Sealey, Draper, and Faithfull feature hardened steel construction that maintains accuracy over years of workshop use. Robust pivot mechanisms ensure blades remain secure with repeated use, whilst clear markings ensure easy reference.

Range Coverage: Verify the pitch range covered suits your applications. Metric gauges typically span 0.25mm to 6mm pitch, whilst imperial gauges cover various TPI ranges. Specialist sets like the Sealey 26-piece nut and bolt thread checking gauge expand functionality beyond simple screw pitch identification.

Frequently Asked Questions

What's the difference between metric and imperial thread pitch measurements?

Metric threads measure pitch as the distance between threads in millimetres (e.g., 1.5mm pitch), whilst imperial threads use TPI (threads per inch) – for example, 20 TPI means 20 complete threads within one inch. You cannot interchange these systems, which is why comprehensive sets covering multiple standards are valuable for professional environments.

Do I need separate gauges for internal and external threads?

No – screw pitch gauges work equally well on both external threads (bolts, screws) and internal threads (nuts, threaded holes). Simply place the gauge blade against the thread profile; for internal threads, you may need good lighting and positioning to see the match clearly.

How should I maintain my screw pitch gauges?

Keep gauges clean and lightly oiled to prevent corrosion, particularly in damp workshop environments. Wipe blades after use and store in their case to protect against damage – bent blades lose accuracy permanently. With proper care, quality gauges from brands stocked at MyToolShed.co.uk provide decades of reliable service.