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JBO Thread Ring Gauge (NoGo) - UNF - Right Hand - 3A - 1/2 x 20
SKU:JBO-501128
The JBO Thread Ring Gauge (NoGo) is a precision tool used to verify external threads on fasteners and threaded components. It’s built for manufacturing environments, automotive shops, aerospace Q...
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Specification
| Thread Form | UNF |
| Size | 1/2 |
| Pitch | 20 |
| Gauge Type | Ring Gauge (NoGo) |
| Thread Direction | Right Hand |
| Tolerance | 3A |
£100.55
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 precision tool used to verify external threads on fasteners and threaded components. It’s built for manufacturing environments, automotive shops, aerospace QA labs, and workshop teams that require quick, reliable conformance checks. This NoGo gauge helps ensure parts meet exact thread standards before they move to the next step in your process.
Designed to UNF 1/2 x 20, Right Hand, 3A, this gauge provides fast, reliable conformance checks. The NoGo design makes non-conforming threads easy to spot, reducing guesswork and preventing misfit or failed assemblies. Crafted from hardened steel, it stands up to daily use while preserving measurement accuracy.
- NoGo Verification for Quick Pass/Fail: The NoGo feature delivers an immediate, clear pass/fail result for threaded parts, speeding inspections and helping prevent incorrect assemblies.
- UNF 1/2 x 20 Right-Hand, 3A Compliance: Specifically built to the UNF right-hand 3A standard, ensuring consistent measurements and dependable interchangeability across parts and suppliers.
- Hardened Steel Construction for Durability: Robust, wear-resistant material maintains accuracy through repeated use in busy shop environments.
Using the JBO Thread Ring Gauge NoGo helps you streamline quality control, reduce inspection time, and improve the reliability of threaded connections. It supports tighter tolerances and more consistent results across your workflow, giving you confidence in every assembly and shipment.
| Thread Form | UNF |
| Size | 1/2 |
| Pitch | 20 |
| Gauge Type | Ring Gauge (NoGo) |
| 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 (NoGo) - Unified
View full collection →You are viewing JBO-501128. 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 Viewing | 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 | 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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