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JBO Thread Plug Gauge - UNJF Go-No/Go - Right Hand - 3B - 1/2 x 20
SKU:JBO-511608
The JBO Thread Plug Gauge - UNJF Go-No/Go - Right Hand - 3B - 1/2 x 20 is a precision inspection tool for verifying UNJF-threaded holes. Its compact, hand-size design makes it ideal for manufactur...
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Specification
| Thread Form | UNJF |
| Size | 1/2 |
| Pitch | 20 |
| Gauge Type | Plug Gauge (D/E) |
| Thread Direction | Right Hand |
| Tolerance | 3B |
£118.42
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 Plug Gauge - UNJF Go-No/Go - Right Hand - 3B - 1/2 x 20 is a precision inspection tool for verifying UNJF-threaded holes. Its compact, hand-size design makes it ideal for manufacturing, automotive, aerospace, and shop-floor QC tasks, where fast, repeatable checks are essential.
With a dedicated go and no-go end, it offers a clear, tactile pass/fail indication for each hole you measure — helping you confirm correct thread engagement, proper depth, and consistent thread quality without guesswork.
- Go/No-Go quick checks: Dual ends deliver decisive pass/fail results, speeding inspections and reducing rework by eliminating guesswork on hole suitability.
- Right-hand, 3B tolerance class: Specifically designed for UNJF right-hand threads in the 3B class, ensuring reliable compatibility with common assemblies and consistent results across parts.
- Rugged, ergonomic construction: Knurled grip and precisely machined ends provide secure handling and repeatable measurements in busy work environments, supporting long service life.
Using the JBO UNJF Go-No/Go plug gauge helps streamline setups, quickly flag out-of-tolerance holes, and ensure threaded components assemble correctly, improving overall workflow, reducing downtime, and delivering dependable results batch after batch.
| Thread Form | UNJF |
| Size | 1/2 |
| Pitch | 20 |
| Gauge Type | Plug Gauge (D/E) |
| Thread Direction | Right Hand |
| Tolerance | 3B |
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 Plug Gauges - Unified Go-No/Go
View full collection →You are viewing JBO-511608. Click any other SKU to view its full details.
| Product SKU | Size | Pitch | Price | Stock | Order |
|---|---|---|---|---|---|
| JBO-512363 | No. 1 | 64 | £127.21 | 5 days | |
| JBO-512368 | No. 2 | 56 | £96.83 | 5 days | |
| JBO-512373 | No. 3 | 48 | £96.83 | 5 days | |
| JBO-512375 | No. 4 | 40 | £82.24 | In Stock | |
| JBO-512382 | No. 5 | 40 | £82.24 | 5 days | |
| JBO-512384 | No. 6 | 32 | £68.99 | 5 days | |
| JBO-512389 | No. 8 | 32 | £65.36 | 5 days | |
| JBO-512365 | No. 10 | 24 | £63.94 | 5 days | |
| JBO-512367 | No. 12 | 24 | £69.30 | 5 days | |
| JBO-512403 | 1/4 | 20 | £62.41 | 5 days | |
| JBO-512410 | 5/16 | 18 | £62.41 | 5 days | |
| JBO-512408 | 3/8 | 16 | £64.37 | 5 days | |
| JBO-512415 | 7/16 | 14 | £69.74 | 5 days | |
| JBO-512401 | 1/2 | 13 | £71.61 | 5 days | |
| JBO-512419 | 9/16 | 12 | £77.54 | 5 days | |
| JBO-512413 | 5/8 | 11 | £79.83 | 5 days | |
| JBO-512406 | 3/4 | 10 | £91.24 | 5 days | |
| JBO-512417 | 7/8 | 9 | £106.04 | 5 days | |
| JBO-512392 | 1 | 8 | £119.52 | 5 days | |
| JBO-512398 | 1 1/8 | 7 | £133.78 | 5 days | |
| JBO-512396 | 1 1/4 | 7 | £145.83 | 5 days | |
| JBO-512399 | 1 3/8 | 6 | £169.96 | 5 days | |
| JBO-512394 | 1 1/2 | 6 | £187.50 | 5 days | |
| JBO-512364 | No. 1 | 64 | £166.67 | 5 days | |
| JBO-512369 | No. 2 | 56 | £124.99 | 5 days | |
| JBO-512374 | No. 3 | 48 | £124.99 | 5 days | |
| JBO-512377 | No. 4 | 40 | £106.58 | 5 days | |
| JBO-512383 | No. 5 | 40 | £106.58 | 5 days | |
| JBO-512386 | No. 6 | 32 | £89.16 | 5 days | |
| JBO-512390 | No. 8 | 32 | £84.43 | 5 days | |
| JBO-512366 | No. 10 | 24 | £83.01 | 5 days | |
| JBO-516808 | No. 12 | 24 | £89.69 | 5 days | |
| JBO-512404 | 1/4 | 20 | £82.02 | 5 days | |
| JBO-512412 | 5/16 | 18 | £82.02 | 5 days | |
| JBO-513092 | 3/8 | 16 | £84.22 | 5 days | |
| JBO-512416 | 7/16 | 14 | £90.70 | 5 days | |
| JBO-512402 | 1/2 | 13 | £93.76 | 5 days | |
| JBO-512420 | 9/16 | 12 | £100.67 | 5 days | |
| JBO-512414 | 5/8 | 11 | £104.82 | 5 days | |
| JBO-512407 | 3/4 | 10 | £119.52 | 5 days | |
| JBO-512418 | 7/8 | 9 | £137.06 | 5 days | |
| JBO-512393 | 1 | 8 | £155.70 | 5 days | |
| JBO-517324 | No. 1 | 64 | £183.12 | 5 days | |
| JBO-517325 | No. 2 | 56 | £139.25 | 5 days | |
| JBO-517326 | No. 3 | 48 | £139.25 | 5 days | |
| JBO-514701 | No. 4 | 40 | £118.42 | 5 days | |
| JBO-517327 | No. 5 | 40 | £118.42 | 5 days | |
| JBO-514702 | No. 6 | 32 | £99.13 | 5 days | |
| JBO-514703 | No. 8 | 32 | £94.09 | 5 days | |
| JBO-514070 | No. 10 | 24 | £92.44 | 5 days | |
| JBO-517328 | No. 12 | 24 | £99.68 | 5 days | |
| JBO-512405 | 1/4 | 20 | £91.01 | 5 days | |
| JBO-517329 | 5/16 | 18 | £91.01 | 5 days | |
| JBO-512409 | 3/8 | 16 | £93.64 | 5 days | |
| JBO-517330 | 7/16 | 14 | £100.67 | 5 days | |
| JBO-516810 | 1/2 | 13 | £104.29 | 5 days | |
| JBO-517331 | 9/16 | 12 | £111.84 | 5 days | |
| JBO-517332 | 5/8 | 11 | £116.23 | 5 days | |
| JBO-514704 | 3/4 | 10 | £131.59 | 5 days | |
| JBO-517333 | 7/8 | 9 | £153.51 | 5 days | |
| JBO-514705 | 1 | 8 | £172.16 | 5 days | |
| JBO-517334 | 1 1/8 | 7 | £196.27 | 5 days | |
| JBO-517335 | 1 1/4 | 7 | £209.44 | 5 days | |
| JBO-517336 | 1 3/8 | 6 | £244.52 | 5 days | |
| JBO-517337 | 1 1/2 | 6 | £273.04 | 5 days | |
| JBO-512421 | No. 0 | 80 | £120.61 | 5 days | |
| JBO-512424 | No. 1 | 72 | £106.37 | 5 days | |
| JBO-512432 | No. 2 | 64 | £118.42 | 5 days | |
| JBO-512434 | No. 3 | 56 | £110.75 | 5 days | |
| JBO-512436 | No. 4 | 48 | £97.06 | 5 days | |
| JBO-512438 | No. 5 | 44 | £86.41 | 5 days | |
| JBO-512440 | No. 6 | 40 | £72.59 | 5 days | |
| JBO-512442 | No. 8 | 36 | £68.75 | 5 days | |
| JBO-512426 | No. 10 | 32 | £63.28 | 5 days | |
| JBO-512431 | No. 12 | 28 | £69.30 | 5 days | |
| JBO-512456 | 1/4 | 28 | £62.41 | 5 days | |
| JBO-512466 | 5/16 | 24 | £62.41 | 5 days | |
| JBO-512462 | 3/8 | 24 | £64.47 | 5 days | |
| JBO-512472 | 7/16 | 20 | £66.89 | 5 days | |
| JBO-512454 | 1/2 | 20 | £71.61 | 5 days | |
| JBO-512478 | 9/16 | 18 | £75.56 | 5 days | |
| JBO-512469 | 5/8 | 18 | £79.83 | 5 days | |
| JBO-512460 | 3/4 | 16 | £89.59 | 5 days | |
| JBO-512476 | 7/8 | 14 | £100.88 | 5 days | |
| JBO-512444 | 1 | 12 | £110.75 | 5 days | |
| JBO-512451 | 1 1/8 | 12 | £126.10 | 5 days | |
| JBO-512449 | 1 1/4 | 12 | £132.68 | 5 days | |
| JBO-512453 | 1 3/8 | 12 | £151.32 | 5 days | |
| JBO-512446 | 1 1/2 | 12 | £166.67 | 5 days | |
| JBO-512422 | No. 0 | 80 | £157.90 | 5 days | |
| JBO-512425 | No. 1 | 72 | £137.06 | 5 days | |
| JBO-512433 | No. 2 | 64 | £154.62 | 5 days | |
| JBO-512435 | No. 3 | 56 | £144.74 | 5 days | |
| JBO-512437 | No. 4 | 48 | £126.10 | 5 days | |
| JBO-512439 | No. 5 | 44 | £111.84 | 5 days | |
| JBO-512441 | No. 6 | 40 | £94.30 | 5 days | |
| JBO-512443 | No. 8 | 36 | £89.05 | 5 days | |
| JBO-512428 | No. 10 | 32 | £82.24 | 5 days | |
| JBO-516811 | No. 12 | 28 | £89.69 | 5 days | |
| JBO-512458 | 1/4 | 28 | £82.02 | 5 days | |
| JBO-512467 | 5/16 | 24 | £82.02 | 5 days | |
| JBO-512463 | 3/8 | 24 | £84.33 | 5 days | |
| JBO-512473 | 7/16 | 20 | £87.73 | 5 days | |
| JBO-512455 | 1/2 | 20 | £93.97 | 5 days | |
| JBO-512479 | 9/16 | 18 | £97.81 | In Stock | |
| JBO-512470 | 5/8 | 18 | £104.82 | 5 days | |
| JBO-512461 | 3/4 | 16 | £117.33 | 5 days | |
| JBO-512477 | 7/8 | 14 | £129.40 | 5 days | |
| JBO-512445 | 1 | 12 | £143.64 | 5 days | |
| JBO-512452 | 1 1/8 | 12 | £163.39 | 5 days | |
| JBO-512450 | 1 1/4 | 12 | £174.35 | 5 days | |
| JBO-513533 | 1 3/8 | 12 | £197.38 | 5 days | |
| JBO-512448 | 1 1/2 | 12 | £214.91 | 5 days | |
| JBO-517341 | No. 0 | 80 | £169.96 | 5 days | |
| JBO-517342 | No. 1 | 72 | £149.13 | 5 days | |
| JBO-517343 | No. 2 | 64 | £166.67 | 5 days | |
| JBO-517344 | No. 3 | 56 | £155.70 | 5 days | |
| JBO-517345 | No. 4 | 48 | £133.78 | 5 days | |
| JBO-517346 | No. 5 | 44 | £120.61 | 5 days | |
| JBO-517347 | No. 6 | 40 | £104.82 | 5 days | |
| JBO-517348 | No. 8 | 36 | £98.80 | 5 days | |
| JBO-512430 | No. 10 | 32 | £91.35 | 5 days | |
| JBO-517349 | No. 12 | 28 | £99.68 | 5 days | |
| JBO-512459 | 1/4 | 28 | £91.01 | 5 days | |
| JBO-512468 | 5/16 | 24 | £91.01 | 5 days | |
| JBO-512464 | 3/8 | 24 | £93.97 | 5 days | |
| JBO-514344 | 7/16 | 20 | £97.72 | 5 days | |
| JBO-516996 | 1/2 | 20 | £104.29 | 5 days | |
| JBO-512480 | 9/16 | 18 | £108.89 | 5 days | |
| JBO-512471 | 5/8 | 18 | £116.23 | 5 days | |
| JBO-516813 | 3/4 | 16 | £129.40 | 5 days | |
| JBO-513423 | 7/8 | 14 | £145.83 | 5 days | |
| JBO-513491 | 1 | 12 | £160.09 | 5 days | |
| JBO-514147 | 1 1/8 | 12 | £182.03 | 5 days | |
| JBO-517350 | 1 1/4 | 12 | £195.18 | 5 days | |
| JBO-514709 | 1 3/8 | 12 | £219.30 | 5 days | |
| JBO-517351 | 1 1/2 | 12 | £239.05 | 5 days | |
| JBO-511537 | No. 12 | 32 | £81.03 | 5 days | |
| JBO-511550 | 1/4 | 32 | £81.03 | 5 days | |
| JBO-511560 | 5/16 | 32 | £84.22 | 5 days | |
| JBO-511558 | 3/8 | 32 | £86.19 | 5 days | |
| JBO-511565 | 7/16 | 2 | £89.16 | 5 days | |
| JBO-511548 | 1/2 | 28 | £90.79 | 5 days | |
| JBO-511569 | 9/16 | 24 | £94.63 | 5 days | |
| JBO-511562 | 5/8 | 24 | £97.93 | 5 days | |
| JBO-511552 | 11/16 | 24 | £101.87 | 5 days | |
| JBO-511556 | 3/4 | 20 | £105.05 | 5 days | |
| JBO-511554 | 13/16 | 20 | £109.65 | 5 days | |
| JBO-511568 | 7/8 | 20 | £115.14 | 5 days | |
| JBO-511555 | 15/16 | 20 | £119.52 | 5 days | |
| JBO-511539 | 1 | 20 | £123.91 | 5 days | |
| JBO-511543 | 1 1/16 | 18 | £130.48 | 5 days | |
| JBO-511542 | 1 1/8 | 18 | £137.06 | 5 days | |
| JBO-511545 | 1 3/16 | 18 | £145.83 | 5 days | |
| JBO-511541 | 1 1/4 | 18 | £152.43 | 5 days | |
| JBO-511544 | 1 3/8 | 18 | £168.86 | 5 days | |
| JBO-511547 | 1 7/16 | 18 | £177.65 | 5 days | |
| JBO-511540 | 1 1/2 | 18 | £186.41 | 5 days | |
| JBO-514880 | 1 9/16 | 18 | £202.87 | 5 days | |
| JBO-517352 | No. 12 | 32 | £107.36 | 5 days | |
| JBO-516900 | 1/4 | 32 | £107.36 | 5 days | |
| JBO-517353 | 5/16 | 32 | £111.84 | 5 days | |
| JBO-517354 | 3/8 | 32 | £114.03 | 5 days | |
| JBO-514710 | 7/16 | 2 | £117.33 | 5 days | |
| JBO-517355 | 1/2 | 28 | £119.52 | 5 days | |
| JBO-517356 | 9/16 | 24 | £124.99 | 5 days | |
| JBO-517357 | 5/8 | 24 | £129.40 | 5 days | |
| JBO-517358 | 11/16 | 24 | £133.78 | 5 days | |
| JBO-514711 | 3/4 | 20 | £139.25 | 5 days | |
| JBO-517359 | 13/16 | 20 | £145.83 | 5 days | |
| JBO-517360 | 7/8 | 20 | £153.51 | 5 days | |
| JBO-517361 | 15/16 | 20 | £160.09 | 5 days | |
| JBO-517362 | 1 | 20 | £163.39 | 5 days | |
| JBO-512599 | 1/4 | 36 | £206.14 | 5 days | |
| JBO-512583 | 1 | 32 | £357.46 | 5 days | |
| JBO-512603 | 11/16 | 16 | £296.06 | 5 days | |
| JBO-512604 | 13/16 | 16 | £304.83 | 5 days | |
| JBO-512618 | 7/8 | 16 | £328.97 | 5 days | |
| JBO-513082 | 1 | 16 | £336.63 | 5 days | |
| JBO-514092 | 1 1/16 | 16 | £339.93 | 5 days | |
| JBO-512593 | 1 3/16 | 16 | £347.59 | 5 days | |
| JBO-512580 | 1 | 14 | £315.79 | 5 days | |
| JBO-512588 | 1 1/16 | 12 | £290.57 | 5 days | |
| JBO-512592 | 1 3/16 | 12 | £309.22 | 5 days | |
| JBO-512594 | 1 5/16 | 12 | £350.89 | 5 days | |
| JBO-512586 | 1 1/8 | 8 | £373.92 | 5 days | |
| JBO-512585 | 1 1/4 | 8 | £425.44 | 5 days | |
| JBO-512591 | 1 3/8 | 8 | £458.34 | 5 days | |
| JBO-512584 | 1 1/2 | 8 | £460.54 | 5 days | |
| JBO-514228 | No. 2 | 56 | £145.83 | 5 days | |
| JBO-511603 | No. 4 | 40 | £124.99 | 5 days | |
| JBO-511604 | No. 6 | 32 | £114.03 | 5 days | |
| JBO-511605 | No. 8 | 32 | £107.57 | 5 days | |
| JBO-514625 | No. 10 | 24 | £110.75 | 5 days | |
| JBO-518292 | 1/4 | 20 | £110.75 | 5 days | |
| JBO-516556 | 5/16 | 18 | £107.57 | 5 days | |
| JBO-515276 | 3/8 | 16 | £109.22 | 5 days | |
| JBO-515969 | 7/16 | 14 | £133.78 | 5 days | |
| JBO-514760 | No. 4 | 48 | £131.59 | 5 days | |
| JBO-518725 | No. 6 | 40 | £118.42 | 5 days | |
| JBO-514327 | No. 8 | 36 | £111.84 | 5 days | |
| JBO-511606 | No. 10 | 32 | £104.51 | 5 days | |
| JBO-517771 | No. 12 | 28 | £110.75 | 5 days | |
| JBO-511609 | 1/4 | 28 | £104.51 | 5 days | |
| JBO-511612 | 5/16 | 24 | £104.51 | 5 days | |
| JBO-511611 | 3/8 | 24 | £107.57 | 5 days | |
| JBO-511615 | 7/16 | 20 | £111.84 | 5 days | |
| JBO-511608 Viewing | 1/2 | 20 | £118.42 | 5 days | |
| JBO-511617 | 9/16 | 18 | £124.99 | 5 days | |
| JBO-511614 | 5/8 | 18 | £132.68 | 5 days | |
| JBO-511610 | 3/4 | 16 | £149.13 | 5 days | |
| JBO-511616 | 7/8 | 14 | £164.47 | 5 days | |
| JBO-511607 | 1 | 12 | £179.84 | 5 days | |
| JBO-516765 | 1/4 | 28 | £162.28 | 5 days | |
| JBO-511613 | 5/16 | 24 | £162.28 | 5 days | |
| JBO-520938 | 3/8 | 24 | £167.77 | 5 days | |
| JBO-513270 | 1/2 | 20 | £183.12 | 5 days | |
| JBO-514326 | 3/4 | 16 | £231.36 | 5 days |
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