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JBO Thread Plug Gauge - UNJF Go-No/Go - Left Hand - 3B - 3/8 x 24
SKU:JBO-520938
The JBO Thread Plug Gauge is a precision inspection tool built to verify UNJF (Unified Fine) threads in left-hand holes. It’s ideal for manufacturers, automotive shops, aerospace assemblies, and ...
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Specification
| Thread Form | UNJF |
| Size | 3/8 |
| Pitch | 24 |
| Gauge Type | Plug Gauge (D/E) |
| Thread Direction | Left Hand |
| Tolerance | 3B |
£167.77
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 is a precision inspection tool built to verify UNJF (Unified Fine) threads in left-hand holes. It’s ideal for manufacturers, automotive shops, aerospace assemblies, and precision workshops that rely on quick, reliable go/no-go checks for 3/8 x 24 threads in class 3B. With its compact, dual-ended design, you can test both the minimum and maximum limits with one instrument, keeping your workflow efficient.
This gauge is designed for heavy use in demanding environments. It features a knurled, textured sleeve for a secure grip and durable metal ends machined to tight tolerances. The left-hand configuration and UNJF Go-No/Go specification ensure compatibility with your threaded components and deliver consistent results across inspections.
- Dual-ended Go/No-Go design: Quickly verify that threads meet the required limits with one tool, reducing inspection time and eliminating guesswork.
- Left-hand UNJF 3B 3/8 x 24 compatibility: Precisely engineered to the UNJF standard for left-hand threads, providing reliable pass/fail decisions every check.
- Rugged, knurled construction: Built for durability in busy environments, with a textured grip and corrosion-resistant finish that stands up to daily use.
This plug gauge helps streamline quality control by delivering clear, repeatable results that support accurate assembly and reduced downtime. With its focused, user-friendly design, you’ll gain confidence in every measurement, improve workflow efficiency, and maintain consistent threading checks across your production line.
| Thread Form | UNJF |
| Size | 3/8 |
| Pitch | 24 |
| Gauge Type | Plug Gauge (D/E) |
| Thread Direction | Left 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-520938. 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 | 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 Viewing | 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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