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JBO Thread Ring Gauge (NoGo) - UNEF - Left Hand - 2A - 7/8 x 20
SKU:JBO-506509
The JBO Thread Ring Gauge (NoGo) is a precision tool for verifying external UNEF threads on fasteners and machined parts. Specifically designed for left-hand threads in the 7/8 x 20 size and clas...
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Specification
| Thread Form | UNEF |
| Size | 7/8 |
| Pitch | 20 |
| Gauge Type | Ring Gauge (NoGo) |
| Thread Direction | Left Hand |
| Tolerance | 2A |
£218.21
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 for verifying external UNEF threads on fasteners and machined parts. Specifically designed for left-hand threads in the 7/8 x 20 size and class 2A, this gauge helps inspectors and machinists confirm that components meet Unified thread standards.
Built for daily shop use, the NoGo design provides a clear pass/fail indication, speeding up quality checks and reducing guesswork during assembly. Crafted from hardened steel, it resists wear to maintain accurate measurements over time, even with frequent handling and inspection workloads.
- No-Go Design for Quick Conformity Checks: Quickly identifies non-conforming threads, reducing inspection time and rework by showing a clear pass/fail result for the 7/8 x 20 UNEF left-hand threads.
- Hardened Steel Construction for Durability: Withstands daily use in busy workshops, maintaining strength and accuracy and resisting wear that can drift gauges over time.
- Exact UNEF Left-Hand 7/8 x 20, 2A Class: Ensures measurements align with the standard, providing reliable checks that support correct part fitment and quality control.
Using this gauge streamlines quality control by delivering fast, reliable checks for left-hand external threads. It supports consistent results across manufacturing, automotive, and aerospace workflows, helps prevent misfits and returns, and keeps your threading inspections accurate over the life of the tool.
| Thread Form | UNEF |
| Size | 7/8 |
| Pitch | 20 |
| 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-506509. 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 | 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 Viewing | 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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