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JBO Thread Ring Gauge (NoGo) - Metric Fine - Right Hand - 6g - M21 x 0.5
SKU:JBO-502755
The JBO Thread Ring Gauge (NoGo) – Metric Fine is a precision inspection tool designed to verify external thread diameters on fasteners and threaded components. Built for engineers, quality contr...
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Specification
| Thread Form | Metric |
| Size | M21 |
| Pitch | 0.5 |
| Gauge Type | Ring Gauge (NoGo) |
| Thread Direction | Right Hand |
| Tolerance | 6 g |
£281.80
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) – Metric Fine is a precision inspection tool designed to verify external thread diameters on fasteners and threaded components. Built for engineers, quality control professionals, machinists, and workshop technicians, it provides reliable Go/NoGo checks to confirm adherence to exact M21 x 0.5, right-hand, 6g specifications.
Crafted from hardened steel, this gauge delivers long-lasting performance in demanding environments. Its durable design resists wear and maintains dimensional stability through repeated use, cleaning, and handling on busy shop floors. The straightforward form makes it easy to use during standard inspection routines, helping you quickly identify parts that fall outside tolerance.
- Exact metric fine-thread specification (M21 x 0.5, 6g, Right Hand): Calibrated to the NoGo limit for precise, reliable pass/fail checks, helping prevent out-of-tolerance parts from progressing in production.
- Hardened steel construction: Delivers superior wear resistance and dimensional stability, ensuring consistent accuracy over many inspections and years of use.
- Easy identification of non-conforming threads: Enables fast, unambiguous quality decisions on the shop floor, reducing inspection time and minimizing rework.
This gauge supports efficient quality control workflows by providing clear, repeatable results that you can trust across batches. With its rugged construction and precise sizing, it helps you lock in thread integrity, streamline assembly readiness, and maintain high standards in manufacturing, machining, and maintenance applications.
| Thread Form | Metric |
| Size | M21 |
| Pitch | 0.5 |
| Gauge Type | Ring Gauge (NoGo) |
| Thread Direction | Right Hand |
| Tolerance | 6 g |
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) - Metric Fine
View full collection →You are viewing JBO-502755. Click any other SKU to view its full details.
| Product SKU | Size | Pitch | Price | Stock | Order |
|---|---|---|---|---|---|
| JBO-503693 | M1 | 0.2 | £479.18 | 5 days | |
| JBO-503705 | M1.2 | 0.2 | £467.11 | 5 days | |
| JBO-500143 | M1.4 | 0.2 | £456.15 | 5 days | |
| JBO-500150 | M1.6 | 0.2 | £439.70 | 5 days | |
| JBO-503213 | M1.8 | 0.2 | £418.87 | 5 days | |
| JBO-500413 | M2 | 0.2 | £412.29 | 5 days | |
| JBO-500436 | M2.5 | 0.2 | £403.52 | 5 days | |
| JBO-500416 | M2 | 0.25 | £312.51 | 5 days | |
| JBO-500423 | M2.2 | 0.25 | £288.38 | 5 days | |
| JBO-500437 | M2.5 | 0.25 | £303.75 | 5 days | |
| JBO-503545 | M3 | 0.25 | £297.15 | 5 days | |
| JBO-504324 | M3.5 | 0.25 | £297.15 | 5 days | |
| JBO-503710 | M4 | 0.25 | £285.10 | 5 days | |
| JBO-503841 | M5 | 0.25 | £281.80 | 5 days | |
| JBO-503492 | M6 | 0.25 | £281.80 | 5 days | |
| JBO-500438 | M2.5 | 0.3 | £109.11 | 5 days | |
| JBO-500607 | M3 | 0.3 | £86.74 | 5 days | |
| JBO-500617 | M3.5 | 0.3 | £85.09 | 5 days | |
| JBO-500742 | M4 | 0.3 | £78.30 | 5 days | |
| JBO-500757 | M4.5 | 0.3 | £120.61 | 5 days | |
| JBO-500834 | M5 | 0.3 | £124.99 | 5 days | |
| JBO-500907 | M6 | 0.3 | £124.99 | 5 days | |
| JBO-500952 | M7 | 0.3 | £156.81 | 5 days | |
| JBO-500992 | M8 | 0.3 | £156.81 | 5 days | |
| JBO-501026 | M9 | 0.3 | £161.19 | 5 days | |
| JBO-500169 | M10 | 0.3 | £161.19 | 5 days | |
| JBO-500620 | M3.5 | 0.5 | £114.03 | 5 days | |
| JBO-500745 | M4 | 0.5 | £71.28 | 5 days | |
| JBO-500758 | M4.5 | 0.5 | £93.76 | 5 days | |
| JBO-500836 | M5 | 0.5 | £71.28 | 5 days | |
| JBO-500849 | M5.5 | 0.5 | £203.95 | 5 days | |
| JBO-500910 | M6 | 0.5 | £72.05 | 5 days | |
| JBO-500922 | M6.5 | 0.5 | £203.95 | 5 days | |
| JBO-500953 | M7 | 0.5 | £75.33 | 5 days | |
| JBO-502740 | M7.5 | 0.5 | £200.65 | 5 days | |
| JBO-500993 | M8 | 0.5 | £77.31 | 5 days | |
| JBO-501011 | M8.5 | 0.5 | £200.65 | 5 days | |
| JBO-501027 | M9 | 0.5 | £84.12 | 5 days | |
| JBO-500170 | M10 | 0.5 | £86.62 | 5 days | |
| JBO-500204 | M11 | 0.5 | £105.05 | 5 days | |
| JBO-500231 | M12 | 0.5 | £99.13 | 5 days | |
| JBO-500262 | M13 | 0.5 | £127.21 | 5 days | |
| JBO-500284 | M14 | 0.5 | £120.61 | 5 days | |
| JBO-500313 | M15 | 0.5 | £129.40 | 5 days | |
| JBO-500336 | M16 | 0.5 | £132.68 | 5 days | |
| JBO-500361 | M17 | 0.5 | £151.32 | 5 days | |
| JBO-500374 | M18 | 0.5 | £150.21 | 5 days | |
| JBO-500397 | M19 | 0.5 | £172.16 | 5 days | |
| JBO-500455 | M20 | 0.5 | £162.28 | 5 days | |
| JBO-502755 Viewing | M21 | 0.5 | £281.80 | 5 days | |
| JBO-500482 | M22 | 0.5 | £292.77 | 5 days | |
| JBO-500502 | M23 | 0.5 | £292.77 | 5 days | |
| JBO-500515 | M24 | 0.5 | £292.77 | 5 days | |
| JBO-500534 | M25 | 0.5 | £304.83 | 5 days | |
| JBO-502743 | M26 | 0.5 | £328.97 | 5 days | |
| JBO-500563 | M27 | 0.5 | £328.97 | 5 days | |
| JBO-500580 | M28 | 0.5 | £328.97 | 5 days | |
| JBO-502976 | M29 | 0.5 | £328.97 | 5 days | |
| JBO-500628 | M30 | 0.5 | £328.97 | 5 days | |
| JBO-503260 | M31 | 0.5 | £361.85 | 5 days | |
| JBO-502943 | M32 | 0.5 | £361.85 | 5 days | |
| JBO-502980 | M33 | 0.5 | £368.43 | 5 days | |
| JBO-500676 | M34 | 0.5 | £368.43 | 5 days | |
| JBO-500685 | M35 | 0.5 | £376.11 | 5 days | |
| JBO-503263 | M36 | 0.5 | £381.60 | 5 days | |
| JBO-503630 | M37 | 0.5 | £381.60 | 5 days | |
| JBO-502815 | M38 | 0.5 | £441.89 | 5 days | |
| JBO-500724 | M39 | 0.5 | £441.89 | 5 days | |
| JBO-500760 | M40 | 0.5 | £441.89 | 5 days | |
| JBO-500843 | M5 | 0.75 | £73.47 | 5 days | |
| JBO-500916 | M6 | 0.75 | £56.26 | 5 days | |
| JBO-500957 | M7 | 0.75 | £67.98 | 5 days | |
| JBO-500998 | M8 | 0.75 | £58.45 | 5 days | |
| JBO-501031 | M9 | 0.75 | £73.80 | 5 days | |
| JBO-500174 | M10 | 0.75 | £63.71 | 5 days | |
| JBO-500208 | M11 | 0.75 | £81.81 | 5 days | |
| JBO-500234 | M12 | 0.75 | £74.79 | 5 days | |
| JBO-500263 | M13 | 0.75 | £93.55 | 5 days | |
| JBO-500287 | M14 | 0.75 | £80.70 | 5 days | |
| JBO-500316 | M15 | 0.75 | £105.83 | 5 days | |
| JBO-500339 | M16 | 0.75 | £93.10 | 5 days | |
| JBO-500362 | M17 | 0.75 | £117.33 | 5 days | |
| JBO-500375 | M18 | 0.75 | £100.22 | 5 days | |
| JBO-500398 | M19 | 0.75 | £120.61 | 5 days | |
| JBO-500456 | M20 | 0.75 | £106.80 | 5 days | |
| JBO-500474 | M21 | 0.75 | £133.78 | 5 days | |
| JBO-500484 | M22 | 0.75 | £126.10 | 5 days | |
| JBO-500503 | M23 | 0.75 | £144.74 | 5 days | |
| JBO-500516 | M24 | 0.75 | £133.78 | 5 days | |
| JBO-500535 | M25 | 0.75 | £134.87 | 5 days | |
| JBO-500547 | M26 | 0.75 | £148.02 | 5 days | |
| JBO-500564 | M27 | 0.75 | £161.19 | 5 days | |
| JBO-500582 | M28 | 0.75 | £164.47 | 5 days | |
| JBO-500592 | M29 | 0.75 | £202.87 | 5 days | |
| JBO-500630 | M30 | 0.75 | £164.47 | 5 days | |
| JBO-500648 | M31 | 0.75 | £310.32 | 5 days | |
| JBO-500651 | M32 | 0.75 | £313.60 | 5 days | |
| JBO-500666 | M33 | 0.75 | £321.28 | 5 days | |
| JBO-500677 | M34 | 0.75 | £330.05 | 5 days | |
| JBO-500686 | M35 | 0.75 | £336.63 | 5 days | |
| JBO-500699 | M36 | 0.75 | £344.31 | 5 days | |
| JBO-500710 | M37 | 0.75 | £350.89 | 5 days | |
| JBO-500714 | M38 | 0.75 | £360.76 | 5 days | |
| JBO-500725 | M39 | 0.75 | £403.52 | 5 days | |
| JBO-500761 | M40 | 0.75 | £376.11 | 5 days | |
| JBO-501003 | M8 | 1 | £51.88 | 5 days | |
| JBO-501034 | M9 | 1 | £66.35 | 5 days | |
| JBO-500179 | M10 | 1 | £58.12 | 5 days | |
| JBO-500211 | M11 | 1 | £75.00 | 5 days | |
| JBO-500239 | M12 | 1 | £65.90 | 5 days | |
| JBO-500266 | M13 | 1 | £88.27 | 5 days | |
| JBO-500292 | M14 | 1 | £70.95 | 5 days | |
| JBO-500318 | M15 | 1 | £92.98 | 5 days | |
| JBO-500343 | M16 | 1 | £77.64 | 5 days | |
| JBO-500365 | M17 | 1 | £90.04 | 5 days | |
| JBO-500377 | M18 | 1 | £85.65 | 5 days | |
| JBO-500399 | M19 | 1 | £104.18 | 5 days | |
| JBO-500458 | M20 | 1 | £91.90 | 5 days | |
| JBO-500476 | M21 | 1 | £111.84 | 5 days | |
| JBO-500486 | M22 | 1 | £101.54 | 5 days | |
| JBO-500505 | M23 | 1 | £117.33 | 5 days | |
| JBO-500518 | M24 | 1 | £108.45 | 5 days | |
| JBO-500537 | M25 | 1 | £115.14 | 5 days | |
| JBO-500548 | M26 | 1 | £119.52 | 5 days | |
| JBO-500565 | M27 | 1 | £121.72 | 5 days | |
| JBO-500583 | M28 | 1 | £127.21 | 5 days | |
| JBO-500593 | M29 | 1 | £203.95 | 5 days | |
| JBO-500631 | M30 | 1 | £128.29 | 5 days | |
| JBO-500652 | M32 | 1 | £143.64 | 5 days | |
| JBO-500667 | M33 | 1 | £145.83 | 5 days | |
| JBO-500678 | M34 | 1 | £149.13 | 5 days | |
| JBO-500687 | M35 | 1 | £153.51 | 5 days | |
| JBO-500700 | M36 | 1 | £159.00 | 5 days | |
| JBO-500715 | M38 | 1 | £164.47 | 5 days | |
| JBO-500726 | M39 | 1 | £202.87 | 5 days | |
| JBO-500762 | M40 | 1 | £177.65 | 5 days | |
| JBO-500778 | M42 | 1 | £182.03 | 5 days | |
| JBO-500793 | M45 | 1 | £196.27 | 5 days | |
| JBO-500808 | M48 | 1 | £207.25 | 5 days | |
| JBO-500852 | M50 | 1 | £212.72 | 5 days | |
| JBO-500862 | M52 | 1 | £223.68 | 5 days | |
| JBO-502793 | M55 | 1 | £232.47 | 5 days | |
| JBO-500878 | M56 | 1 | £236.85 | 5 days | |
| JBO-500890 | M58 | 1 | £244.52 | 5 days | |
| JBO-500924 | M60 | 1 | £254.39 | 5 days | |
| JBO-500932 | M62 | 1 | £300.45 | 5 days | |
| JBO-504314 | M64 | 1 | £308.13 | 5 days | |
| JBO-500941 | M65 | 1 | £312.51 | 5 days | |
| JBO-520154 | M68 | 1 | £324.56 | 5 days | |
| JBO-520155 | M70 | 1 | £333.35 | 5 days | |
| JBO-520156 | M72 | 1 | £347.59 | 5 days | |
| JBO-500972 | M75 | 1 | £372.81 | 5 days | |
| JBO-520157 | M76 | 1 | £376.11 | 5 days | |
| JBO-520158 | M78 | 1 | £399.14 | 5 days | |
| JBO-520159 | M80 | 1 | £393.65 | 5 days | |
| JBO-500187 | M10 | 1.25 | £67.98 | 5 days | |
| JBO-500246 | M12 | 1.25 | £86.74 | 5 days | |
| JBO-500297 | M14 | 1.25 | £96.28 | 5 days | |
| JBO-500350 | M16 | 1.25 | £255.50 | 5 days | |
| JBO-500384 | M18 | 1.25 | £274.12 | 5 days | |
| JBO-500463 | M20 | 1.25 | £284.00 | 5 days | |
| JBO-505741 | M22 | 1.25 | £303.75 | 5 days | |
| JBO-500523 | M24 | 1.25 | £333.35 | 5 days | |
| JBO-500250 | M12 | 1.5 | £62.27 | 5 days | |
| JBO-500271 | M13 | 1.5 | £142.55 | 5 days | |
| JBO-500301 | M14 | 1.5 | £66.45 | 5 days | |
| JBO-500323 | M15 | 1.5 | £88.60 | 5 days | |
| JBO-500351 | M16 | 1.5 | £72.36 | 5 days | |
| JBO-500369 | M17 | 1.5 | £109.22 | 5 days | |
| JBO-500385 | M18 | 1.5 | £77.97 | 5 days | |
| JBO-500403 | M19 | 1.5 | £156.81 | 5 days | |
| JBO-500464 | M20 | 1.5 | £86.62 | 5 days | |
| JBO-500478 | M21 | 1.5 | £212.72 | 5 days | |
| JBO-500491 | M22 | 1.5 | £92.32 | 5 days | |
| JBO-500524 | M24 | 1.5 | £98.14 | 5 days | |
| JBO-500541 | M25 | 1.5 | £102.76 | 5 days | |
| JBO-500553 | M26 | 1.5 | £105.92 | 5 days | |
| JBO-500569 | M27 | 1.5 | £109.65 | 5 days | |
| JBO-500587 | M28 | 1.5 | £111.84 | 5 days | |
| JBO-500636 | M30 | 1.5 | £117.33 | 5 days | |
| JBO-500656 | M32 | 1.5 | £124.99 | 5 days | |
| JBO-500668 | M33 | 1.5 | £128.29 | 5 days | |
| JBO-500680 | M34 | 1.5 | £141.45 | 5 days | |
| JBO-500688 | M35 | 1.5 | £132.68 | 5 days | |
| JBO-500702 | M36 | 1.5 | £135.97 | 5 days | |
| JBO-500716 | M38 | 1.5 | £143.64 | 5 days | |
| JBO-500727 | M39 | 1.5 | £159.00 | 5 days | |
| JBO-500763 | M40 | 1.5 | £151.32 | 5 days | |
| JBO-500779 | M42 | 1.5 | £161.19 | 5 days | |
| JBO-500794 | M45 | 1.5 | £168.86 | 5 days | |
| JBO-500810 | M48 | 1.5 | £176.54 | 5 days | |
| JBO-500853 | M50 | 1.5 | £183.12 | 5 days | |
| JBO-500863 | M52 | 1.5 | £194.08 | 5 days | |
| JBO-500874 | M55 | 1.5 | £200.65 | 5 days | |
| JBO-500879 | M56 | 1.5 | £203.95 | 5 days | |
| JBO-500891 | M58 | 1.5 | £209.44 | 5 days | |
| JBO-500925 | M60 | 1.5 | £216.02 | 5 days | |
| JBO-500933 | M62 | 1.5 | £224.79 | 5 days | |
| JBO-500936 | M64 | 1.5 | £232.47 | 5 days | |
| JBO-500942 | M65 | 1.5 | £235.75 | 5 days | |
| JBO-500945 | M68 | 1.5 | £244.52 | 5 days | |
| JBO-500964 | M70 | 1.5 | £256.58 | 5 days | |
| JBO-500967 | M72 | 1.5 | £265.35 | 5 days | |
| JBO-500973 | M75 | 1.5 | £279.61 | 5 days | |
| JBO-500976 | M76 | 1.5 | £304.83 | 5 days | |
| JBO-500978 | M78 | 1.5 | £300.45 | 5 days | |
| JBO-501013 | M80 | 1.5 | £304.83 | 5 days | |
| JBO-501018 | M82 | 1.5 | £316.90 | 5 days | |
| JBO-501019 | M85 | 1.5 | £328.97 | 5 days | |
| JBO-501022 | M88 | 1.5 | £349.78 | 5 days | |
| JBO-503431 | M90 | 1.5 | £350.89 | 5 days | |
| JBO-501041 | M92 | 1.5 | £361.85 | 5 days | |
| JBO-501043 | M95 | 1.5 | £375.00 | 5 days | |
| JBO-520170 | M98 | 1.5 | £434.23 | 5 days | |
| JBO-500194 | M100 | 1.5 | £398.03 | 5 days | |
| JBO-500197 | M102 | 1.5 | £449.58 | 5 days | |
| JBO-500199 | M105 | 1.5 | £418.87 | 5 days | |
| JBO-520171 | M108 | 1.5 | £483.56 | 5 days | |
| JBO-503404 | M110 | 1.5 | £444.09 | 5 days | |
| JBO-500217 | M112 | 1.5 | £539.49 | 5 days | |
| JBO-520172 | M115 | 1.5 | £547.16 | 5 days | |
| JBO-520173 | M118 | 1.5 | £595.41 | 5 days | |
| JBO-520174 | M120 | 1.5 | £581.17 | 5 days | |
| JBO-500261 | M122 | 1.5 | £595.41 | 5 days | |
| JBO-504425 | M125 | 1.5 | £618.43 | 5 days | |
| JBO-504426 | M128 | 1.5 | £671.07 | 5 days | |
| JBO-500273 | M130 | 1.5 | £652.42 | 5 days | |
| JBO-520175 | M132 | 1.5 | £700.67 | 5 days | |
| JBO-505452 | M135 | 1.5 | £701.78 | 5 days | |
| JBO-520176 | M138 | 1.5 | £723.70 | 5 days | |
| JBO-520177 | M140 | 1.5 | £740.15 | 5 days | |
| JBO-520178 | M142 | 1.5 | £750.02 | 5 days | |
| JBO-520179 | M145 | 1.5 | £762.09 | 5 days | |
| JBO-520180 | M148 | 1.5 | £781.82 | 5 days | |
| JBO-520181 | M150 | 1.5 | £781.82 | 5 days | |
| JBO-500394 | M18 | 2 | £97.93 | 5 days | |
| JBO-500471 | M20 | 2 | £92.32 | 5 days | |
| JBO-500499 | M22 | 2 | £98.24 | 5 days | |
| JBO-500529 | M24 | 2 | £102.53 | 5 days | |
| JBO-500546 | M25 | 2 | £108.78 | 5 days | |
| JBO-500558 | M26 | 2 | £114.03 | 5 days | |
| JBO-500575 | M27 | 2 | £112.95 | 5 days | |
| JBO-500591 | M28 | 2 | £120.61 | 5 days | |
| JBO-500641 | M30 | 2 | £122.80 | 5 days | |
| JBO-500662 | M32 | 2 | £129.40 | 5 days | |
| JBO-500671 | M33 | 2 | £130.48 | 5 days | |
| JBO-500684 | M34 | 2 | £171.05 | 5 days | |
| JBO-500694 | M35 | 2 | £173.24 | 5 days | |
| JBO-500705 | M36 | 2 | £139.25 | 5 days | |
| JBO-500722 | M38 | 2 | £150.21 | 5 days |
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