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JBO Thread Ring Gauge (NoGo) - UNEF - Left Hand - 2A - 1/2 x 28
SKU:JBO-503779
The JBO Thread Ring Gauge (NoGo) is a precise inspection tool designed to verify external threads to the Unified thread standard. Ideal for engineers, inspectors, manufacturers, and workshop team...
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Specification
| Thread Form | UNEF |
| Size | 1/2 |
| Pitch | 28 |
| Gauge Type | Ring Gauge (NoGo) |
| Thread Direction | Left Hand |
| Tolerance | 2A |
£133.78
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 (NoGo) is a precise inspection tool designed to verify external threads to the Unified thread standard. Ideal for engineers, inspectors, manufacturers, and workshop teams, it helps ensure every threaded component meets exact specifications with quick, reliable checks.
Built for real-world use, this NoGo gauge features a hardened steel construction for durability in busy production environments. Its exacting profile supports fast, repeatable measurements, so you can trust your thread checks day after day.
- NoGo design for fast non-conformance identification: Quickly determine if a thread is out of tolerance, enabling immediate pass/fail decisions and reducing inspection time.
- Hardened steel construction for durability: Withstands daily handling and high-volume checking, delivering consistent performance and long service life.
- UNEF 2A Left-Hand 1/2 x 28 external thread gauge: Precisely matched to the UNEF standard for left-hand threads, ensuring accurate, repeatable measurements and proper fitment in compatible assemblies.
In daily workflows, this gauge helps you accelerate quality checks, minimize rework, and confirm proper thread engagement across manufacturing, automotive, and aerospace applications. Rely on it for consistent results, straightforward inspection, and confidence in every threaded connection you produce.
| Thread Form | UNEF |
| Size | 1/2 |
| Pitch | 28 |
| Gauge Type | Ring Gauge (NoGo) |
| Thread Direction | Left Hand |
| Tolerance | 2A |
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 (NoGo) - Unified
View full collection →You are viewing JBO-503779. Click any other SKU to view its full details.
| Product SKU | Size | Pitch | Price | Stock | Order |
|---|---|---|---|---|---|
| JBO-501051 | No. 1 | 64 | £114.03 | 5 days | |
| JBO-501057 | No. 2 | 56 | £86.19 | 5 days | |
| JBO-501061 | No. 3 | 48 | £103.52 | 5 days | |
| JBO-501063 | No. 4 | 40 | £75.45 | 5 days | |
| JBO-501066 | No. 5 | 40 | £69.08 | 5 days | |
| JBO-501067 | No. 6 | 32 | £58.90 | 5 days | |
| JBO-501070 | No. 8 | 32 | £55.39 | 5 days | |
| JBO-501053 | No. 10 | 24 | £54.28 | 5 days | |
| JBO-501055 | No. 12 | 24 | £63.28 | 5 days | |
| JBO-501080 | 1/4 | 20 | £51.88 | 5 days | |
| JBO-501088 | 5/16 | 18 | £55.15 | 5 days | |
| JBO-501085 | 3/8 | 16 | £60.08 | 5 days | |
| JBO-501093 | 7/16 | 14 | £65.48 | 5 days | |
| JBO-501078 | 1/2 | 13 | £71.94 | 5 days | |
| JBO-501097 | 9/16 | 12 | £99.25 | 5 days | |
| JBO-501091 | 5/8 | 11 | £84.43 | 5 days | |
| JBO-501083 | 3/4 | 10 | £104.51 | 5 days | |
| JBO-501095 | 7/8 | 9 | £127.21 | 5 days | |
| JBO-501072 | 1 | 8 | £137.06 | 5 days | |
| JBO-501075 | 1 1/8 | 7 | £183.12 | 5 days | |
| JBO-501074 | 1 1/4 | 7 | £198.46 | 5 days | |
| JBO-501077 | 1 3/8 | 6 | £213.83 | 5 days | |
| JBO-501073 | 1 1/2 | 6 | £233.56 | 5 days | |
| JBO-501076 | 1 3/4 | 5 | £292.77 | 5 days | |
| JBO-503352 | 2 | 4.5 | £335.54 | 5 days | |
| JBO-502964 | 2 1/4 | 4.5 | £382.68 | 5 days | |
| JBO-541018 | 2 1/2 | 4 | £427.63 | 5 days | |
| JBO-507589 | 2 3/4 | 4 | £476.99 | 5 days | |
| JBO-501052 | No. 1 | 64 | £167.77 | 5 days | |
| JBO-501060 | No. 2 | 56 | £128.29 | 5 days | |
| JBO-501062 | No. 3 | 48 | £135.97 | 5 days | |
| JBO-501065 | No. 4 | 40 | £105.48 | 5 days | |
| JBO-502874 | No. 5 | 40 | £96.83 | 5 days | |
| JBO-501068 | No. 6 | 32 | £82.35 | 5 days | |
| JBO-501071 | No. 8 | 32 | £77.41 | 5 days | |
| JBO-501054 | No. 10 | 24 | £77.64 | 5 days | |
| JBO-501056 | No. 12 | 24 | £82.14 | 5 days | |
| JBO-501081 | 1/4 | 20 | £76.22 | 5 days | |
| JBO-501089 | 5/16 | 18 | £81.03 | 5 days | |
| JBO-501086 | 3/8 | 16 | £88.06 | 5 days | |
| JBO-501094 | 7/16 | 14 | £98.14 | 5 days | |
| JBO-501079 | 1/2 | 13 | £107.90 | 5 days | |
| JBO-503178 | 9/16 | 12 | £120.61 | 5 days | |
| JBO-501092 | 5/8 | 11 | £128.29 | 5 days | |
| JBO-502798 | 3/4 | 10 | £156.81 | 5 days | |
| JBO-501096 | 7/8 | 9 | £189.69 | 5 days | |
| JBO-503179 | 1 | 8 | £209.44 | 5 days | |
| JBO-506412 | No. 1 | 64 | £163.39 | 5 days | |
| JBO-506413 | No. 2 | 56 | £129.40 | 5 days | |
| JBO-506414 | No. 3 | 48 | £148.02 | 5 days | |
| JBO-504045 | No. 4 | 40 | £112.95 | 5 days | |
| JBO-506415 | No. 5 | 40 | £103.52 | 5 days | |
| JBO-501069 | No. 6 | 32 | £88.15 | 5 days | |
| JBO-506416 | No. 8 | 32 | £83.11 | 5 days | |
| JBO-503428 | No. 10 | 24 | £81.36 | 5 days | |
| JBO-505540 | No. 12 | 24 | £87.84 | 5 days | |
| JBO-501082 | 1/4 | 20 | £77.76 | 5 days | |
| JBO-501090 | 5/16 | 18 | £82.80 | 5 days | |
| JBO-501087 | 3/8 | 16 | £90.25 | 5 days | |
| JBO-506417 | 7/16 | 14 | £98.14 | 5 days | |
| JBO-506418 | 1/2 | 13 | £107.90 | 5 days | |
| JBO-506420 | 9/16 | 12 | £118.42 | 5 days | |
| JBO-504046 | 5/8 | 11 | £130.48 | 5 days | |
| JBO-501084 | 3/4 | 10 | £156.81 | 5 days | |
| JBO-506422 | 7/8 | 9 | £189.69 | 5 days | |
| JBO-506423 | 1 | 8 | £209.44 | 5 days | |
| JBO-506424 | 1 1/8 | 7 | £245.62 | 5 days | |
| JBO-506426 | 1 1/4 | 7 | £268.65 | 5 days | |
| JBO-506428 | 1 3/8 | 6 | £299.34 | 5 days | |
| JBO-506430 | 1 1/2 | 6 | £317.99 | 5 days | |
| JBO-501099 | No. 0 | 80 | £126.10 | 5 days | |
| JBO-501101 | No. 1 | 72 | £105.38 | 5 days | |
| JBO-501108 | No. 2 | 64 | £105.26 | 5 days | |
| JBO-501110 | No. 3 | 56 | £104.95 | 5 days | |
| JBO-501112 | No. 4 | 48 | £92.98 | 5 days | |
| JBO-501114 | No. 5 | 44 | £74.55 | 5 days | |
| JBO-501116 | No. 6 | 40 | £71.72 | 5 days | |
| JBO-501118 | No. 8 | 36 | £66.35 | 5 days | |
| JBO-501103 | No. 10 | 32 | £52.75 | 5 days | |
| JBO-501106 | No. 12 | 28 | £63.28 | 5 days | |
| JBO-501130 | 1/4 | 28 | £51.97 | 5 days | |
| JBO-501140 | 5/16 | 24 | £55.15 | 5 days | |
| JBO-501137 | 3/8 | 24 | £60.08 | 5 days | |
| JBO-501146 | 7/16 | 20 | £64.82 | 5 days | |
| JBO-501127 | 1/2 | 20 | £71.94 | 5 days | |
| JBO-501152 | 9/16 | 18 | £77.41 | 5 days | |
| JBO-501143 | 5/8 | 18 | £85.65 | 5 days | |
| JBO-501133 | 3/4 | 16 | £99.68 | 5 days | |
| JBO-501149 | 7/8 | 14 | £117.33 | 5 days | |
| JBO-501120 | 1 | 12 | £131.59 | 5 days | |
| JBO-501125 | 1 1/8 | 12 | £148.02 | 5 days | |
| JBO-501124 | 1 1/4 | 12 | £161.19 | 5 days | |
| JBO-501126 | 1 3/8 | 12 | £175.43 | 5 days | |
| JBO-501123 | 1 1/2 | 12 | £186.41 | 5 days | |
| JBO-501100 | No. 0 | 80 | £176.54 | 5 days | |
| JBO-501102 | No. 1 | 72 | £148.02 | 5 days | |
| JBO-501109 | No. 2 | 64 | £137.06 | 5 days | |
| JBO-501111 | No. 3 | 56 | £135.97 | 5 days | |
| JBO-501113 | No. 4 | 48 | £121.72 | 5 days | |
| JBO-501115 | No. 5 | 44 | £96.83 | 5 days | |
| JBO-501117 | No. 6 | 40 | £93.10 | 5 days | |
| JBO-501119 | No. 8 | 36 | £85.65 | 5 days | |
| JBO-501104 | No. 10 | 32 | £73.58 | 5 days | |
| JBO-501107 | No. 12 | 28 | £82.14 | 5 days | |
| JBO-501131 | 1/4 | 28 | £72.81 | 5 days | |
| JBO-501141 | 5/16 | 24 | £77.10 | 5 days | |
| JBO-501138 | 3/8 | 24 | £84.22 | 5 days | |
| JBO-501147 | 7/16 | 20 | £90.46 | 5 days | |
| JBO-501128 | 1/2 | 20 | £100.55 | 5 days | |
| JBO-501153 | 9/16 | 18 | £108.45 | 5 days | |
| JBO-501144 | 5/8 | 18 | £119.52 | 5 days | |
| JBO-501134 | 3/4 | 16 | £139.25 | 5 days | |
| JBO-501150 | 7/8 | 14 | £164.47 | 5 days | |
| JBO-501121 | 1 | 12 | £183.12 | 5 days | |
| JBO-502758 | 1 1/8 | 12 | £207.25 | 5 days | |
| JBO-503208 | 1 1/4 | 12 | £225.87 | 5 days | |
| JBO-503210 | 1 3/8 | 12 | £245.62 | 5 days | |
| JBO-502767 | 1 1/2 | 12 | £264.27 | 5 days | |
| JBO-506458 | No. 0 | 80 | £176.54 | 5 days | |
| JBO-506460 | No. 1 | 72 | £148.02 | 5 days | |
| JBO-506461 | No. 2 | 64 | £137.06 | 5 days | |
| JBO-506462 | No. 3 | 56 | £135.97 | 5 days | |
| JBO-506463 | No. 4 | 48 | £121.72 | 5 days | |
| JBO-506465 | No. 5 | 44 | £96.83 | 5 days | |
| JBO-506466 | No. 6 | 40 | £93.10 | 5 days | |
| JBO-506468 | No. 8 | 36 | £85.65 | 5 days | |
| JBO-501105 | No. 10 | 32 | £76.44 | 5 days | |
| JBO-506470 | No. 12 | 28 | £83.67 | 5 days | |
| JBO-501132 | 1/4 | 28 | £72.81 | 5 days | |
| JBO-501142 | 5/16 | 24 | £81.03 | 5 days | |
| JBO-501139 | 3/8 | 24 | £84.22 | 5 days | |
| JBO-501148 | 7/16 | 20 | £92.98 | 5 days | |
| JBO-501129 | 1/2 | 20 | £104.72 | 5 days | |
| JBO-501154 | 9/16 | 18 | £116.23 | 5 days | |
| JBO-501145 | 5/8 | 18 | £119.52 | 5 days | |
| JBO-501135 | 3/4 | 16 | £139.25 | 5 days | |
| JBO-501151 | 7/8 | 14 | £164.47 | 5 days | |
| JBO-501122 | 1 | 12 | £183.12 | 5 days | |
| JBO-503126 | 1 1/8 | 12 | £207.25 | 5 days | |
| JBO-506473 | 1 1/4 | 12 | £225.87 | 5 days | |
| JBO-506476 | 1 3/8 | 12 | £245.62 | 5 days | |
| JBO-502851 | 1 1/2 | 12 | £264.27 | 5 days | |
| JBO-500006 | No. 12 | 32 | £74.79 | 5 days | |
| JBO-500019 | 1/4 | 32 | £74.79 | 5 days | |
| JBO-500033 | 5/16 | 32 | £80.16 | 5 days | |
| JBO-500029 | 3/8 | 32 | £85.20 | 5 days | |
| JBO-500036 | 7/16 | 2 | £90.46 | 5 days | |
| JBO-500016 | 1/2 | 28 | £94.52 | 5 days | |
| JBO-500040 | 9/16 | 24 | £104.60 | 5 days | |
| JBO-500034 | 5/8 | 24 | £111.84 | 5 days | |
| JBO-500022 | 11/16 | 24 | £120.61 | 5 days | |
| JBO-500025 | 3/4 | 20 | £127.21 | 5 days | |
| JBO-500023 | 13/16 | 20 | £133.78 | 5 days | |
| JBO-500039 | 7/8 | 20 | £144.74 | 5 days | |
| JBO-500024 | 15/16 | 20 | £155.70 | 5 days | |
| JBO-500007 | 1 | 20 | £163.39 | 5 days | |
| JBO-500011 | 1 1/16 | 18 | £173.24 | 5 days | |
| JBO-505428 | 1 1/8 | 18 | £179.84 | 5 days | |
| JBO-500013 | 1 3/16 | 18 | £189.69 | 5 days | |
| JBO-500009 | 1 1/4 | 18 | £202.87 | 5 days | |
| JBO-500014 | 1 5/16 | 18 | £213.83 | 5 days | |
| JBO-500012 | 1 3/8 | 18 | £225.87 | 5 days | |
| JBO-500015 | 1 7/16 | 18 | £236.85 | 5 days | |
| JBO-500008 | 1 1/2 | 18 | £248.90 | 5 days | |
| JBO-503813 | 1 9/16 | 18 | £266.46 | 5 days | |
| JBO-506504 | No. 12 | 32 | £105.71 | 5 days | |
| JBO-500021 | 1/4 | 32 | £105.71 | 5 days | |
| JBO-506505 | 5/16 | 32 | £116.23 | 5 days | |
| JBO-506506 | 3/8 | 32 | £121.72 | 5 days | |
| JBO-500038 | 7/16 | 2 | £127.21 | 5 days | |
| JBO-503779 Viewing | 1/2 | 28 | £133.78 | 5 days | |
| JBO-505872 | 9/16 | 24 | £145.83 | 5 days | |
| JBO-503137 | 5/8 | 24 | £167.77 | 5 days | |
| JBO-506507 | 11/16 | 24 | £178.73 | 5 days | |
| JBO-500028 | 3/4 | 20 | £188.61 | 5 days | |
| JBO-506508 | 13/16 | 20 | £202.87 | 5 days | |
| JBO-506509 | 7/8 | 20 | £218.21 | 5 days | |
| JBO-506510 | 15/16 | 20 | £233.56 | 5 days | |
| JBO-504057 | 1 | 20 | £244.52 | 5 days | |
| JBO-501232 | 1/4 | 36 | £207.25 | 5 days | |
| JBO-501205 | 1 | 32 | £421.06 | 5 days | |
| JBO-501237 | 11/16 | 16 | £350.89 | 5 days | |
| JBO-501240 | 13/16 | 16 | £307.02 | 5 days | |
| JBO-501259 | 7/8 | 16 | £313.60 | 5 days | |
| JBO-501204 | 1 | 16 | £350.89 | 5 days | |
| JBO-540054 | 1 1/16 | 16 | £370.62 | 5 days | |
| JBO-501223 | 1 3/16 | 16 | £407.90 | 5 days | |
| JBO-501202 | 1 | 14 | £288.38 | 5 days | |
| JBO-501214 | 1 1/16 | 12 | £321.28 | 5 days | |
| JBO-501222 | 1 3/16 | 12 | £364.04 | 5 days | |
| JBO-501225 | 1 5/16 | 12 | £359.66 | 5 days | |
| JBO-502756 | 1 5/8 | 12 | £459.45 | 5 days | |
| JBO-501216 | 1 3/4 | 12 | £441.89 | 5 days | |
| JBO-501227 | 1 7/8 | 12 | £482.48 | 5 days | |
| JBO-502835 | 2 | 12 | £490.14 | 5 days | |
| JBO-501213 | 1 1/8 | 8 | £357.46 | 5 days | |
| JBO-501209 | 1 1/4 | 8 | £359.66 | 5 days | |
| JBO-501221 | 1 3/8 | 8 | £387.07 | 5 days | |
| JBO-501207 | 1 1/2 | 8 | £463.83 | 5 days | |
| JBO-501224 | 1 5/8 | 8 | £486.86 | 5 days | |
| JBO-501218 | 1 3/4 | 8 | £552.65 | 5 days | |
| JBO-503355 | 2 | 8 | £596.51 | 5 days | |
| JBO-504211 | No. 2 | 56 | £167.77 | 5 days | |
| JBO-503594 | No. 4 | 40 | £139.25 | 5 days | |
| JBO-500119 | No. 6 | 32 | £120.61 | 5 days | |
| JBO-500120 | No. 8 | 32 | £111.84 | 5 days | |
| JBO-544018 | No. 10 | 24 | £111.84 | 5 days | |
| JBO-544019 | 1/4 | 20 | £111.84 | 5 days | |
| JBO-544020 | 5/16 | 18 | £111.84 | 5 days | |
| JBO-544021 | 3/8 | 16 | £116.23 | 5 days | |
| JBO-554997 | 7/16 | 14 | £148.02 | 5 days | |
| JBO-544022 | No. 4 | 48 | £143.64 | 5 days | |
| JBO-505348 | No. 6 | 40 | £117.33 | 5 days | |
| JBO-500123 | No. 8 | 36 | £108.02 | 5 days | |
| JBO-500122 | No. 10 | 32 | £94.30 | 5 days | |
| JBO-504245 | No. 12 | 28 | £108.02 | 5 days | |
| JBO-500125 | 1/4 | 28 | £94.30 | 5 days | |
| JBO-500127 | 5/16 | 24 | £98.80 | 5 days | |
| JBO-500126 | 3/8 | 24 | £106.58 | 5 days | |
| JBO-500129 | 7/16 | 20 | £116.23 | 5 days | |
| JBO-502985 | 1/2 | 20 | £128.29 | 5 days | |
| JBO-500130 | 9/16 | 18 | £135.97 | 5 days | |
| JBO-500128 | 5/8 | 18 | £153.51 | 5 days | |
| JBO-503100 | 3/4 | 16 | £176.54 | 5 days | |
| JBO-503652 | 7/8 | 14 | £207.25 | 5 days | |
| JBO-500124 | 1 | 12 | £233.56 | 5 days | |
| JBO-544318 | 1/4 | 28 | £151.32 | 5 days | |
| JBO-504653 | 5/16 | 24 | £159.00 | 5 days | |
| JBO-503867 | 3/8 | 24 | £171.05 | 5 days | |
| JBO-544329 | 1/2 | 20 | £206.14 | 5 days | |
| JBO-503729 | 3/4 | 16 | £248.90 | 5 days |
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