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JBO Thread Plug Gauge (GO) - UNC - Right Hand - 2B - 2 1/2 x 4

SKU:JBO-520137

The JBO Thread Plug Gauge (GO) for UNC threads is a precision inspection tool designed to verify internal thread holes quickly and reliably. Its go/no-go design helps technicians confirm whether ... Read more ↓
Thread FormUNC
Size2 1/2
Pitch4
Gauge TypePlug Gauge (GO)
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£196.27
Prices shown ex. VAT
5 days estimated lead time — subject to availability
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Free delivery over £50 ex VAT
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14-day returns
30+ years expertise
Klarna
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01732 887334
Mon – Thurs 8:30 – 17:30 · Fri 8:30 – 16:30

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Description

The JBO Thread Plug Gauge (GO) for UNC threads is a precision inspection tool designed to verify internal thread holes quickly and reliably. Its go/no-go design helps technicians confirm whether a threaded hole conforms to Unified thread standards, ensuring proper fitment for the fasteners used in your assemblies.

Designed for a wide audience—engineers, buyers, shop-floor technicians, and maintenance teams across manufacturing, automotive, and aerospace—the GO gauge makes thread verification straightforward. The GO end allows immediate identification of properly formed threads, reducing guesswork and preventing costly rework in your quality checks.

  • Go design for fast go/no-go verification: Quickly determine if a threaded hole meets spec; a smooth GO entry signals compliant threads, while resistance indicates a deviation that needs correction.
  • UNC standard size: 2 1/2 x 4, Right Hand, 2B: Precisely matched to common Unified National Coarse threads in the right-hand direction, supporting reliable compatibility with standard fasteners and assemblies.
  • Precise dimensions for repeatable results: Meticulous design and tight tolerances deliver consistent measurements across inspections, boosting confidence in part quality and traceability.

Using this gauge helps streamline inspection workflows, reduce downtime associated with undetected thread faults, and ensure every hole is ready for assembly—supporting reliable performance across production lines and service environments.

Part Numbers

Protool Part Number
JBO-520137
Brand
JBO
Category
Gauge
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Need cutting data? Call 01732 887334 or email sales@protool-ltd.co.uk.
Delivery

Free UK mainland delivery on orders over £50 ex VAT. In-stock items ordered before 4:30pm are dispatched the same working day. Full delivery information.

Returns

14-day returns on unused stock items in original packaging. Special-order and bespoke tooling is non-returnable. Read our returns policy.

Technical Support

Over 30 years of machining experience behind the counter. Call 01732 887334, Mon–Thurs 8:30–17:30, Fri 8:30–16:30.

Trade Accounts

Credit accounts, contract pricing and scheduled call-off orders available for trade customers. Apply for an account.

What time are Protool open?

We are open Monday to Friday between 8:30am and 5pm.

Do you offer Free Next Day delivery?

Yes! We offer Free Next Day delivery via Royal Mail Tracked 24 on all orders over £50 ex VAT*. We also offer Free DPD Local Next Day delivery on all orders over £100 ex VAT*.

We also offer the following:

  • Royal Mail Tracked 24 — £5.90 (FREE on orders over £50 ex VAT*). Order before 4:30pm for next day delivery. No signature required.
  • DPD Local Next Day — £8.00 (FREE on orders over £100 ex VAT*). Standard next day delivery to UK mainland addresses.
  • Royal Mail Special Delivery — £12.50. Guaranteed delivery before 1pm the next working day.
  • DPD Saturday Delivery — £25.00. Must be ordered on Friday before 4pm. Pre-12pm delivery.

For delivery to Scottish Highlands & Islands, Northern Ireland, Republic of Ireland, or overseas locations, additional charges apply. Please see our delivery page for full details, or call us on 01732 887 334.

*T's & C's and exclusions apply. Please see our delivery page for more information on all our services.

Ask our technical team about this tool

Not sure if this is the right tool for your job? Ask us about speeds and feeds, material suitability, holders or alternatives — 30+ years of machining experience on the other end.

Prefer to talk? Call 01732 887334 — Mon–Thurs 8:30–17:30, Fri 8:30–16:30.

Full Range: JBO Thread Plug Gauges (GO) - Unified

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You are viewing JBO-520137. Click any other SKU to view its full details.

Product SKUSizePitchPriceStock Order
JBO-511328 1 3/45£141.45 5 days
JBO-511333 24.5£161.19 5 days
JBO-513180 2 1/44.5£173.24 5 days
JBO-520137 Viewing2 1/24£196.27 5 days
JBO-514464 2 3/44£214.91 5 days
JBO-511394 1 5/812£282.91 5 days
JBO-513514 1 3/412£282.91 5 days
JBO-511396 1 7/812£312.51 5 days
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