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JBO Thread Ring Gauge (GO) - UNC - Right Hand - 3A - 1/4 x 20
SKU:JBO-502407
The JBO Thread Ring Gauge (GO) for UNC right-hand threads is a precision inspection tool designed to confirm external thread diameters align with the UNC 1/4 x 20 standard. Built for machinists, ...
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Specification
| Thread Form | UNC |
| Size | 1/4 |
| Pitch | 20 |
| Gauge Type | Ring Gauge (GO) |
| Thread Direction | Right Hand |
| Tolerance | 3A |
£76.22
Prices shown ex. VAT
5 days estimated lead time
— subject to availability
View Other Sizes →
Free delivery over £50 ex VAT
Secure checkout
14-day returns
30+ years expertise
Pay in 3 interest-free instalments. No extra cost if paid on time. 18+ only.
Learn more about Klarna
Learn more about Klarna
The JBO Thread Ring Gauge (GO) for UNC right-hand threads is a precision inspection tool designed to confirm external thread diameters align with the UNC 1/4 x 20 standard. Built for machinists, inspectors, and quality teams, it provides a fast, reliable pass/fail check that keeps assemblies moving and reduces guesswork in threaded component verification.
Whether you’re setting up a new production line or performing routine quality checks, this GO gauge helps you verify components quickly and consistently, supporting accurate documentation and traceability in your quality system.
- Go/No-Go verification for UNC 1/4 x 20: Quickly determine whether a threaded component meets the GO limit, enabling fast clearance decisions and reducing inspection time.
- Hardened steel construction for durability: Engineered to resist wear in busy workshops, maintaining accurate dimensions over thousands of cycles and demanding use.
- 3A-class, Right-Hand UNC compatibility: Precisely sized for common right-hand UNC threads with 3A tolerance, delivering consistent checks across standard fasteners.
Using the JBO GO gauge helps improve workflow by delivering clear go/no-go results, supporting quality control records, and helping you prevent misfits before assembly. Its robust design and reliable performance contribute to longer tool life and fewer reworks, so you can trust each measurement as part of your precision process.
| Thread Form | UNC |
| Size | 1/4 |
| Pitch | 20 |
| Gauge Type | Ring Gauge (GO) |
| Thread Direction | Right Hand |
| Tolerance | 3A |
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.
★★★★★
Nice experience staff are very helpful and interested...
Staff are very helpful and interested in providing a good service making us the customer feel valued.
★★★★★
first place we look
honest about stock and prices are competitive.
★★★★★
Polite and helpful
Staff are very helpful and polite.Goods that were in stock were dispatched same day and back orders were quick in coming through .
★★★★★
Buying experience
Phone requests are handled quickly and without any fuss. The website is easy to use and straightforward to order from. It’s especially helpful that it shows real‑time availability, so we don’t need to call to confirm whether parts will arrive.
Full Range: JBO Thread Ring Gauges (GO) - Unified
View full collection →You are viewing JBO-502407. Click any other SKU to view its full details.
| Product SKU | Size | Pitch | Price | Stock | Order |
|---|---|---|---|---|---|
| JBO-502377 | No. 1 | 64 | £114.03 | 5 days | |
| JBO-502382 | No. 2 | 56 | £86.19 | 5 days | |
| JBO-502386 | No. 3 | 48 | £103.52 | 5 days | |
| JBO-502388 | No. 4 | 40 | £75.45 | 5 days | |
| JBO-502392 | No. 5 | 40 | £69.08 | 5 days | |
| JBO-502393 | No. 6 | 32 | £58.90 | 5 days | |
| JBO-502396 | No. 8 | 32 | £55.39 | 5 days | |
| JBO-502379 | No. 10 | 24 | £54.28 | 5 days | |
| JBO-505676 | No. 12 | 24 | £63.28 | 5 days | |
| JBO-502406 | 1/4 | 20 | £51.88 | 5 days | |
| JBO-502416 | 5/16 | 18 | £55.15 | 5 days | |
| JBO-502413 | 3/8 | 16 | £60.08 | 5 days | |
| JBO-502421 | 7/16 | 14 | £65.48 | 5 days | |
| JBO-502404 | 1/2 | 13 | £71.94 | 5 days | |
| JBO-502425 | 9/16 | 12 | £99.25 | 5 days | |
| JBO-502419 | 5/8 | 11 | £84.43 | 5 days | |
| JBO-502411 | 3/4 | 10 | £104.51 | 5 days | |
| JBO-502423 | 7/8 | 9 | £127.21 | 5 days | |
| JBO-502398 | 1 | 8 | £137.06 | 5 days | |
| JBO-502401 | 1 1/8 | 7 | £183.12 | 5 days | |
| JBO-502400 | 1 1/4 | 7 | £198.46 | 5 days | |
| JBO-502403 | 1 3/8 | 6 | £213.83 | 5 days | |
| JBO-502399 | 1 1/2 | 6 | £233.56 | 5 days | |
| JBO-502402 | 1 3/4 | 5 | £292.77 | 5 days | |
| JBO-502409 | 2 | 4.5 | £335.54 | 5 days | |
| JBO-502963 | 2 1/4 | 4.5 | £382.68 | 5 days | |
| JBO-502410 | 2 1/2 | 4 | £427.63 | 5 days | |
| JBO-507588 | 2 3/4 | 4 | £476.99 | 5 days | |
| JBO-502378 | No. 1 | 64 | £167.77 | 5 days | |
| JBO-502385 | No. 2 | 56 | £128.29 | 5 days | |
| JBO-502387 | No. 3 | 48 | £135.97 | 5 days | |
| JBO-502391 | No. 4 | 40 | £105.48 | 5 days | |
| JBO-502873 | No. 5 | 40 | £96.83 | 5 days | |
| JBO-502394 | No. 6 | 32 | £82.35 | 5 days | |
| JBO-502397 | No. 8 | 32 | £77.41 | 5 days | |
| JBO-502380 | No. 10 | 24 | £77.64 | 5 days | |
| JBO-502381 | No. 12 | 24 | £82.14 | 5 days | |
| JBO-502407 Viewing | 1/4 | 20 | £76.22 | 5 days | |
| JBO-502417 | 5/16 | 18 | £81.03 | 5 days | |
| JBO-502414 | 3/8 | 16 | £88.06 | 5 days | |
| JBO-502422 | 7/16 | 14 | £98.14 | 5 days | |
| JBO-502405 | 1/2 | 13 | £107.90 | 5 days | |
| JBO-503165 | 9/16 | 12 | £120.61 | 5 days | |
| JBO-502420 | 5/8 | 11 | £128.29 | 5 days | |
| JBO-502797 | 3/4 | 10 | £156.81 | In Stock | |
| JBO-502424 | 7/8 | 9 | £189.69 | 5 days | |
| JBO-503166 | 1 | 8 | £209.44 | 5 days | |
| JBO-506400 | No. 1 | 64 | £163.39 | 5 days | |
| JBO-506401 | No. 2 | 56 | £129.40 | 5 days | |
| JBO-506402 | No. 3 | 48 | £148.02 | 5 days | |
| JBO-504041 | No. 4 | 40 | £112.95 | 5 days | |
| JBO-506403 | No. 5 | 40 | £103.52 | 5 days | |
| JBO-502395 | No. 6 | 32 | £88.15 | 5 days | |
| JBO-506404 | No. 8 | 32 | £83.11 | 5 days | |
| JBO-503427 | No. 10 | 24 | £81.36 | 5 days | |
| JBO-505677 | No. 12 | 24 | £87.84 | 5 days | |
| JBO-502408 | 1/4 | 20 | £77.76 | 5 days | |
| JBO-502418 | 5/16 | 18 | £82.80 | 5 days | |
| JBO-502415 | 3/8 | 16 | £90.25 | 5 days | |
| JBO-506405 | 7/16 | 14 | £98.14 | 5 days | |
| JBO-506406 | 1/2 | 13 | £107.90 | 5 days | |
| JBO-506407 | 9/16 | 12 | £118.42 | 5 days | |
| JBO-504042 | 5/8 | 11 | £130.48 | 5 days | |
| JBO-502412 | 3/4 | 10 | £156.81 | 5 days | |
| JBO-506408 | 7/8 | 9 | £189.69 | 5 days | |
| JBO-504043 | 1 | 8 | £209.44 | 5 days | |
| JBO-506409 | 1 1/8 | 7 | £245.62 | 5 days | |
| JBO-505756 | 1 1/4 | 7 | £268.65 | 5 days | |
| JBO-506410 | 1 3/8 | 6 | £299.34 | 5 days | |
| JBO-506411 | 1 1/2 | 6 | £317.99 | 5 days | |
| JBO-502426 | No. 1 | 72 | £126.10 | 5 days | |
| JBO-502436 | No. 2 | 64 | £105.26 | 5 days | |
| JBO-502438 | No. 3 | 56 | £104.95 | 5 days | |
| JBO-502440 | No. 4 | 48 | £92.98 | 5 days | |
| JBO-502442 | No. 5 | 44 | £74.55 | 5 days | |
| JBO-502444 | No. 6 | 40 | £71.72 | 5 days | |
| JBO-502446 | No. 8 | 36 | £66.35 | 5 days | |
| JBO-502430 | No. 10 | 32 | £52.75 | 5 days | |
| JBO-502433 | No. 12 | 28 | £63.28 | 5 days | |
| JBO-502458 | 1/4 | 28 | £51.97 | 5 days | |
| JBO-502469 | 5/16 | 24 | £55.15 | 5 days | |
| JBO-502466 | 3/8 | 24 | £60.08 | 5 days | |
| JBO-502475 | 7/16 | 20 | £64.82 | 5 days | |
| JBO-502455 | 1/2 | 20 | £71.94 | 5 days | |
| JBO-502481 | 9/16 | 18 | £77.41 | 5 days | |
| JBO-502472 | 5/8 | 18 | £85.65 | 5 days | |
| JBO-502461 | 3/4 | 16 | £99.68 | 5 days | |
| JBO-502478 | 7/8 | 14 | £117.33 | 5 days | |
| JBO-502448 | 1 | 12 | £131.59 | 5 days | |
| JBO-502453 | 1 1/8 | 12 | £148.02 | 5 days | |
| JBO-502452 | 1 1/4 | 12 | £161.19 | 5 days | |
| JBO-502454 | 1 3/8 | 12 | £175.43 | 5 days | |
| JBO-502451 | 1 1/2 | 12 | £186.41 | 5 days | |
| JBO-502427 | No. 0 | 80 | £176.54 | 5 days | |
| JBO-502429 | No. 1 | 72 | £148.02 | 5 days | |
| JBO-502437 | No. 2 | 64 | £137.06 | 5 days | |
| JBO-502439 | No. 3 | 56 | £135.97 | 5 days | |
| JBO-502441 | No. 4 | 48 | £121.72 | 5 days | |
| JBO-502443 | No. 5 | 44 | £96.83 | 5 days | |
| JBO-502445 | No. 6 | 40 | £93.10 | 5 days | |
| JBO-502447 | No. 8 | 36 | £85.65 | 5 days | |
| JBO-502431 | No. 10 | 32 | £73.58 | 5 days | |
| JBO-502435 | No. 12 | 28 | £82.14 | 5 days | |
| JBO-502459 | 1/4 | 28 | £72.81 | 5 days | |
| JBO-502470 | 5/16 | 24 | £77.10 | 5 days | |
| JBO-502467 | 3/8 | 24 | £84.22 | 5 days | |
| JBO-502476 | 7/16 | 20 | £90.46 | 5 days | |
| JBO-502456 | 1/2 | 20 | £100.55 | 5 days | |
| JBO-502482 | 9/16 | 18 | £108.45 | 5 days | |
| JBO-502473 | 5/8 | 18 | £119.52 | 5 days | |
| JBO-502463 | 3/4 | 16 | £139.25 | 5 days | |
| JBO-502479 | 7/8 | 14 | £164.47 | 5 days | |
| JBO-502449 | 1 | 12 | £183.12 | 5 days | |
| JBO-502757 | 1 1/8 | 12 | £207.25 | 5 days | |
| JBO-503207 | 1 1/4 | 12 | £225.87 | 5 days | |
| JBO-503209 | 1 3/8 | 12 | £245.62 | 5 days | |
| JBO-502768 | 1 1/2 | 12 | £264.27 | 5 days | |
| JBO-506438 | No. 0 | 80 | £176.54 | 5 days | |
| JBO-506441 | No. 1 | 72 | £148.02 | 5 days | |
| JBO-506445 | No. 2 | 64 | £137.06 | 5 days | |
| JBO-506448 | No. 3 | 56 | £135.97 | 5 days | |
| JBO-506449 | No. 4 | 48 | £121.72 | 5 days | |
| JBO-506452 | No. 5 | 44 | £96.83 | 5 days | |
| JBO-506453 | No. 6 | 40 | £93.10 | 5 days | |
| JBO-506454 | No. 8 | 36 | £85.65 | 5 days | |
| JBO-502432 | No. 10 | 32 | £76.44 | 5 days | |
| JBO-506455 | No. 12 | 28 | £83.67 | 5 days | |
| JBO-502460 | 1/4 | 28 | £72.81 | 5 days | |
| JBO-502471 | 5/16 | 24 | £81.03 | 5 days | |
| JBO-502468 | 3/8 | 24 | £84.22 | 5 days | |
| JBO-502477 | 7/16 | 20 | £92.98 | 5 days | |
| JBO-502457 | 1/2 | 20 | £104.72 | 5 days | |
| JBO-502483 | 9/16 | 18 | £116.23 | 5 days | |
| JBO-502474 | 5/8 | 18 | £119.52 | 5 days | |
| JBO-502464 | 3/4 | 16 | £139.25 | 5 days | |
| JBO-502480 | 7/8 | 14 | £164.47 | 5 days | |
| JBO-502450 | 1 | 12 | £183.12 | 5 days | |
| JBO-503127 | 1 1/8 | 12 | £207.25 | 5 days | |
| JBO-506456 | 1 1/4 | 12 | £225.87 | 5 days | |
| JBO-506457 | 1 3/8 | 12 | £245.62 | 5 days | |
| JBO-505736 | 1 1/2 | 12 | £264.27 | 5 days | |
| JBO-501299 | No. 12 | 32 | £74.79 | 5 days | |
| JBO-501313 | 1/4 | 32 | £74.79 | 5 days | |
| JBO-501326 | 5/16 | 32 | £80.16 | 5 days | |
| JBO-501323 | 3/8 | 32 | £85.20 | 5 days | |
| JBO-501329 | 7/16 | 2 | £90.46 | 5 days | |
| JBO-501310 | 1/2 | 28 | £94.52 | 5 days | |
| JBO-501334 | 9/16 | 24 | £104.60 | 5 days | |
| JBO-501327 | 5/8 | 24 | £111.84 | 5 days | |
| JBO-501316 | 11/16 | 24 | £120.61 | 5 days | |
| JBO-501319 | 3/4 | 20 | £127.21 | 5 days | |
| JBO-501317 | 13/16 | 20 | £133.78 | 5 days | |
| JBO-501333 | 7/8 | 20 | £144.74 | 5 days | |
| JBO-501318 | 15/16 | 20 | £155.70 | 5 days | |
| JBO-501300 | 1 | 20 | £163.39 | 5 days | |
| JBO-501305 | 1 1/16 | 18 | £173.24 | 5 days | |
| JBO-501303 | 1 1/8 | 18 | £179.84 | 5 days | |
| JBO-501307 | 1 3/16 | 18 | £189.69 | 5 days | |
| JBO-501302 | 1 1/4 | 18 | £202.87 | 5 days | |
| JBO-501308 | 1 5/16 | 18 | £213.83 | 5 days | |
| JBO-501306 | 1 3/8 | 18 | £225.87 | 5 days | |
| JBO-501309 | 1 7/16 | 18 | £236.85 | 5 days | |
| JBO-501301 | 1 1/2 | 18 | £248.90 | 5 days | |
| JBO-506769 | 1 9/16 | 18 | £266.46 | 5 days | |
| JBO-506489 | No. 12 | 32 | £105.71 | 5 days | |
| JBO-501315 | 1/4 | 32 | £105.71 | 5 days | |
| JBO-506490 | 5/16 | 32 | £116.23 | 5 days | |
| JBO-506491 | 3/8 | 32 | £121.72 | 5 days | |
| JBO-501332 | 7/16 | 2 | £127.21 | 5 days | |
| JBO-503778 | 1/2 | 28 | £133.78 | 5 days | |
| JBO-505871 | 9/16 | 24 | £145.83 | 5 days | |
| JBO-503138 | 5/8 | 24 | £167.77 | 5 days | |
| JBO-506492 | 11/16 | 24 | £178.73 | 5 days | |
| JBO-501322 | 3/4 | 20 | £188.61 | 5 days | |
| JBO-506493 | 13/16 | 20 | £202.87 | 5 days | |
| JBO-506494 | 7/8 | 20 | £218.21 | 5 days | |
| JBO-506495 | 15/16 | 20 | £233.56 | 5 days | |
| JBO-504056 | 1 | 20 | £244.52 | 5 days | |
| JBO-502570 | 1/4 | 36 | £207.25 | 5 days | |
| JBO-502546 | 1 | 32 | £421.06 | 5 days | |
| JBO-502576 | 11/16 | 16 | £350.89 | 5 days | |
| JBO-502580 | 13/16 | 16 | £307.02 | 5 days | |
| JBO-502601 | 7/8 | 16 | £313.60 | 5 days | |
| JBO-502545 | 1 | 16 | £350.89 | 5 days | |
| JBO-542688 | 1 1/16 | 16 | £370.62 | 5 days | |
| JBO-502561 | 1 3/16 | 16 | £407.90 | 5 days | |
| JBO-505372 | 1 | 14 | £288.38 | 5 days | |
| JBO-502552 | 1 1/16 | 12 | £321.28 | 5 days | |
| JBO-502560 | 1 3/16 | 12 | £364.04 | 5 days | |
| JBO-502563 | 1 5/16 | 12 | £359.66 | 5 days | |
| JBO-502562 | 1 5/8 | 12 | £459.45 | 5 days | |
| JBO-502554 | 1 3/4 | 12 | £441.89 | 5 days | |
| JBO-502565 | 1 7/8 | 12 | £482.48 | 5 days | |
| JBO-502584 | 2 | 12 | £490.14 | 5 days | |
| JBO-503417 | 1 1/8 | 8 | £357.46 | 5 days | |
| JBO-502549 | 1 1/4 | 8 | £359.66 | 5 days | |
| JBO-552099 | 1 3/8 | 8 | £387.07 | 5 days | |
| JBO-502547 | 1 1/2 | 8 | £463.83 | 5 days | |
| JBO-502924 | 1 5/8 | 8 | £486.86 | 5 days | |
| JBO-502556 | 1 3/4 | 8 | £552.65 | 5 days | |
| JBO-503356 | 2 | 8 | £596.51 | 5 days | |
| JBO-504210 | No. 2 | 56 | £167.77 | 5 days | |
| JBO-503593 | No. 4 | 40 | £139.25 | 5 days | |
| JBO-505569 | No. 6 | 32 | £120.61 | 5 days | |
| JBO-501415 | No. 8 | 32 | £111.84 | 5 days | |
| JBO-547026 | No. 10 | 24 | £111.84 | 5 days | |
| JBO-547027 | 1/4 | 20 | £111.84 | 5 days | |
| JBO-547028 | 5/16 | 18 | £111.84 | 5 days | |
| JBO-507449 | 3/8 | 16 | £116.23 | 5 days | |
| JBO-554996 | 7/16 | 14 | £148.02 | 5 days | |
| JBO-547029 | No. 4 | 48 | £143.64 | 5 days | |
| JBO-505347 | No. 6 | 40 | £117.33 | 5 days | |
| JBO-501418 | No. 8 | 36 | £108.02 | 5 days | |
| JBO-501417 | No. 10 | 32 | £94.30 | 5 days | |
| JBO-504244 | No. 12 | 28 | £108.02 | 5 days | |
| JBO-501419 | 1/4 | 28 | £94.30 | 5 days | |
| JBO-501422 | 5/16 | 24 | £98.80 | 5 days | |
| JBO-501421 | 3/8 | 24 | £106.58 | 5 days | |
| JBO-501424 | 7/16 | 20 | £116.23 | 5 days | |
| JBO-502986 | 1/2 | 20 | £128.29 | 5 days | |
| JBO-501425 | 9/16 | 18 | £135.97 | 5 days | |
| JBO-501423 | 5/8 | 18 | £153.51 | 5 days | |
| JBO-501420 | 3/4 | 16 | £176.54 | 5 days | |
| JBO-503651 | 7/8 | 14 | £207.25 | 5 days | |
| JBO-503703 | 1 | 12 | £233.56 | 5 days | |
| JBO-547575 | 1/4 | 28 | £151.32 | 5 days | |
| JBO-503866 | 3/8 | 24 | £171.05 | 5 days | |
| JBO-547590 | 1/2 | 20 | £206.14 | 5 days |
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