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JBO Thread Plug Gauge - UNF Go-No/Go - Left Hand - 2B - 1/4 x 28
SKU:JBO-512459
The JBO Thread Plug Gauge is a precision tool designed to quickly verify UNF threads, specifically the left-hand variant of 1/4 x 28, with a 2B tolerance. It’s ideal for inspectors, machinists, a...
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Specifications at a glance
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| Thread Form | UNF |
| Size | 1/4 |
| Pitch | 28 |
| Gauge Type | Plug Gauge (D/E) |
£91.01
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.
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Description
The JBO Thread Plug Gauge is a precision tool designed to quickly verify UNF threads, specifically the left-hand variant of 1/4 x 28, with a 2B tolerance. It’s ideal for inspectors, machinists, and quality teams across manufacturing, automotive, and aerospace environments, helping you confirm threaded holes meet universal standards and are ready for use in critical assemblies.
- Go/No-Go quick checks: The simple go/no-go design lets you instantly distinguish conforming from non-conforming threads, speeding up inspections and reducing guesswork in daily QA workflows.
- Left-Hand UNF 1/4 x 28 with 2B tolerance: Precisely matched to the left-hand thread and 2B class tolerances, delivering reliable measurements and consistent fit verification for compatible components.
- Durable, user-friendly construction: Knurled grip and robust ends provide secure handling and long-lasting use in busy workshops, helping readings stay clear and repeatable over time.
Using this gauge helps you streamline thread verification, minimize rework, and maintain tight quality control. Its clear Go/No-Go feedback supports faster decision-making, improving overall workflow and ensuring reliable performance in demanding applications.
Part Numbers
- Protool Part Number
- JBO-512459
- Brand
- JBO
- Category
- Gauge
No downloads are attached to this product yet.
Need cutting data? Call 01732 887334 or email sales@protool-ltd.co.uk.
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
Full Range: JBO Thread Plug Gauges - Unified Go-No/Go
View full collection →You are viewing JBO-512459. 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 Viewing | 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 | 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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