JBO Thread Plug Gauge - Metric Fine Go/No-Go - Right Hand - 6G - M21 x 1

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JBO Thread Plug Gauge - Metric Fine Go/No-Go - Right Hand - 6G - M21 x 1

SKU:JBO-511932

Specifications at a glance

Thread Form	Metric
Size	M21
Pitch	1
Gauge Type	Plug Gauge (D/E)

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£139.25

Prices shown ex. VAT

5 days estimated lead time — subject to availability

Free delivery over £50 ex VAT

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14-day returns

30+ years expertise

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01732 887334

Mon – Thurs 8:30 – 17:30 · Fri 8:30 – 16:30

Compatible certification

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UKAS Calibration Certificate - Screw Plug Gauges up to 100mm/4" (Up To 14 DAYS FROM STOCK) - 1 Per Gauge
£43.60Available to order

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Description

The JBO Thread Plug Gauge is a metric fine Go/No-Go gauge designed to verify internal threads with precision. It’s built for machinists, inspectors, and assembly teams working with M21 x 1 right-hand threads (6G) to quickly validate hole acceptance, even in high-volume productions. The hardened-steel construction delivers durable, long-lasting performance in tough shop environments.

Go/No-Go precision for metric fine threads: Quickly determine if a tapped hole meets the M21 x 1 right-hand 6G tolerance using distinct go and no-go checks, reducing guesswork and rework.
Specialized for M21 x 1 right-hand threads: Precisely matched to this metric fine thread form to ensure consistent, reliable fits in critical assemblies.
Durable, wear-resistant hardened steel: Built to withstand daily use, maintaining accuracy and extending gauge life in demanding workshop conditions.

This gauge speeds up quality control by providing clear pass/fail results, helping your team avoid misfits during assembly and save time on recalibration. With its textured, knurled body for secure handling, you’ll get repeatable measurements across batches and shifts, giving you confidence in every threaded connection.

Part Numbers

Protool Part Number: JBO-511932
Brand: JBO
Category: Gauge

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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.

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Full Range: JBO Thread Plug Gauges - Metric Fine Go/No-Go

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You are viewing JBO-511932. Click any other SKU to view its full details.

Product SKU	Size	Pitch	Price	Stock

JBO-530859	M1	0.2	£332.24	5 days
JBO-528018	M1.2	0.2	£328.97	5 days
JBO-513456	M1.4	0.2	£320.18	5 days
JBO-517010	M1.6	0.2	£305.94	5 days
JBO-513362	M1.8	0.2	£300.45	5 days
JBO-518211	M2	0.2	£290.57	5 days
JBO-530985	M2.5	0.2	£285.10	5 days
JBO-511872	M2	0.25	£214.91	5 days
JBO-511878	M2.2	0.25	£214.91	5 days
JBO-511891	M2.5	0.25	£209.44	5 days
JBO-512053	M3	0.25	£209.44	5 days
JBO-512068	M3.5	0.25	£222.60	5 days
JBO-514142	M4	0.25	£222.60	5 days
JBO-512235	M5	0.25	£220.40	5 days
JBO-513946	M6	0.25	£220.40	5 days
JBO-511892	M2.5	0.35	£155.70	5 days
JBO-512054	M3	0.35	£137.06	5 days
JBO-512069	M3.5	0.35	£137.06	5 days
JBO-512190	M4	0.35	£129.40	5 days
JBO-512205	M4.5	0.35	£185.31	5 days
JBO-512236	M5	0.35	£185.31	5 days
JBO-512270	M6	0.35	£194.08	5 days
JBO-512291	M7	0.35	£194.08	5 days
JBO-512320	M8	0.35	£202.87	5 days
JBO-512348	M9	0.35	£202.87	5 days
JBO-520002	M10	0.35	£209.44	5 days
JBO-512072	M3.5	0.5	£153.51	5 days
JBO-512195	M4	0.5	£102.86	5 days
JBO-512206	M4.5	0.5	£115.14	5 days
JBO-512238	M5	0.5	£99.68	5 days
JBO-512248	M5.5	0.5	£194.08	5 days
JBO-512271	M6	0.5	£98.80	5 days
JBO-512285	M6.5	0.5	£194.08	5 days
JBO-512292	M7	0.5	£101.66	5 days
JBO-512301	M7.5	0.5	£196.27	5 days
JBO-512321	M8	0.5	£102.76	5 days
JBO-512343	M8.5	0.5	£196.27	5 days
JBO-512350	M9	0.5	£117.33	5 days
JBO-511656	M10	0.5	£112.95	5 days
JBO-511681	M11	0.5	£129.40	5 days
JBO-511699	M12	0.5	£122.80	5 days
JBO-511722	M13	0.5	£143.64	5 days
JBO-511736	M14	0.5	£132.68	5 days
JBO-511762	M15	0.5	£157.90	5 days
JBO-511785	M16	0.5	£150.21	5 days
JBO-511812	M17	0.5	£187.50	5 days
JBO-511825	M18	0.5	£168.86	5 days
JBO-511845	M19	0.5	£211.63	5 days
JBO-511909	M20	0.5	£187.50	5 days
JBO-511927	M21	0.5	£287.29	5 days
JBO-511939	M22	0.5	£301.53	5 days
JBO-511960	M23	0.5	£311.41	5 days
JBO-511970	M24	0.5	£304.83	5 days
JBO-514233	M25	0.5	£311.41	5 days
JBO-512999	M26	0.5	£312.51	5 days
JBO-513054	M27	0.5	£312.51	5 days
JBO-513285	M28	0.5	£314.71	5 days
JBO-513562	M29	0.5	£319.09	5 days
JBO-513366	M30	0.5	£319.09	5 days
JBO-512095	M31	0.5	£321.28	5 days
JBO-512097	M32	0.5	£321.28	5 days
JBO-512110	M33	0.5	£378.30	5 days
JBO-512125	M34	0.5	£384.88	5 days
JBO-512134	M35	0.5	£389.26	5 days
JBO-513561	M36	0.5	£401.33	5 days
JBO-514184	M37	0.5	£414.48	5 days
JBO-514226	M38	0.5	£425.44	5 days
JBO-513747	M39	0.5	£439.70	5 days
JBO-514150	M40	0.5	£452.85	5 days
JBO-512243	M5	0.75	£79.38	5 days
JBO-512277	M6	0.75	£66.68	5 days
JBO-512295	M7	0.75	£71.49	5 days
JBO-512326	M8	0.75	£70.07	5 days
JBO-512352	M9	0.75	£79.29	5 days
JBO-511659	M10	0.75	£74.90	5 days
JBO-511682	M11	0.75	£84.88	5 days
JBO-511701	M12	0.75	£80.92	5 days
JBO-511723	M13	0.75	£88.27	5 days
JBO-511739	M14	0.75	£88.27	5 days
JBO-511764	M15	0.75	£94.30	5 days
JBO-511789	M16	0.75	£94.30	5 days
JBO-511813	M17	0.75	£107.57	5 days
JBO-511826	M18	0.75	£99.56	5 days
JBO-511846	M19	0.75	£117.33	5 days
JBO-511910	M20	0.75	£110.75	5 days
JBO-511928	M21	0.75	£126.10	5 days
JBO-511940	M22	0.75	£129.40	5 days
JBO-512997	M23	0.75	£141.45	5 days
JBO-511971	M24	0.75	£139.25	5 days
JBO-511984	M25	0.75	£144.74	5 days
JBO-511993	M26	0.75	£149.13	5 days
JBO-512009	M27	0.75	£150.21	5 days
JBO-512025	M28	0.75	£154.62	5 days
JBO-512034	M29	0.75	£166.67	5 days
JBO-512078	M30	0.75	£160.09	5 days
JBO-513442	M31	0.75	£375.00	5 days
JBO-516791	M32	0.75	£375.00	5 days
JBO-512111	M33	0.75	£376.11	5 days
JBO-516445	M34	0.75	£376.11	5 days
JBO-513917	M35	0.75	£379.41	5 days
JBO-512147	M36	0.75	£379.41	5 days
JBO-513182	M37	0.75	£382.68	5 days
JBO-512159	M38	0.75	£382.68	5 days
JBO-512168	M39	0.75	£392.56	5 days
JBO-512208	M40	0.75	£385.98	5 days
JBO-512331	M8	1	£61.75	5 days
JBO-512356	M9	1	£67.45	5 days
JBO-511663	M10	1	£65.03	5 days
JBO-511684	M11	1	£71.94	5 days
JBO-511703	M12	1	£70.62	5 days
JBO-511724	M13	1	£82.14	5 days
JBO-511745	M14	1	£75.12	5 days
JBO-511766	M15	1	£84.99	5 days
JBO-511792	M16	1	£80.70	5 days
JBO-511815	M17	1	£91.35	5 days
JBO-511829	M18	1	£84.33	5 days
JBO-511849	M19	1	£100.43	5 days
JBO-511911	M20	1	£90.04	5 days
JBO-511930	M21	1	£114.03	5 days
JBO-511942	M22	1	£101.09	5 days
JBO-511961	M23	1	£122.80	5 days
JBO-511972	M24	1	£108.89	5 days
JBO-511985	M25	1	£119.52	5 days
JBO-511994	M26	1	£123.91	5 days
JBO-512011	M27	1	£128.29	5 days
JBO-512026	M28	1	£130.48	5 days
JBO-512035	M29	1	£150.21	5 days
JBO-512079	M30	1	£132.68	5 days
JBO-512098	M32	1	£137.06	5 days
JBO-512112	M33	1	£143.64	5 days
JBO-512126	M34	1	£148.02	5 days
JBO-512135	M35	1	£155.70	5 days
JBO-512148	M36	1	£160.09	5 days
JBO-512160	M38	1	£171.05	5 days
JBO-512169	M39	1	£224.79	5 days
JBO-512209	M40	1	£183.12	5 days
JBO-511675	M10	1.25	£75.78	5 days
JBO-511711	M12	1.25	£80.61	5 days
JBO-511752	M14	1.25	£92.89	5 days
JBO-511800	M16	1.25	£222.60	5 days
JBO-511833	M18	1.25	£264.27	5 days
JBO-511917	M20	1.25	£279.61	5 days
JBO-514324	M22	1.25	£285.10	5 days
JBO-514109	M24	1.25	£289.49	5 days
JBO-511716	M12	1.5	£64.37	5 days
JBO-511728	M13	1.5	£132.68	5 days
JBO-511755	M14	1.5	£68.75	5 days
JBO-511771	M15	1.5	£84.99	5 days
JBO-511802	M16	1.5	£71.84	5 days
JBO-511818	M17	1.5	£119.52	5 days
JBO-511835	M18	1.5	£76.44	5 days
JBO-511855	M19	1.5	£178.73	5 days
JBO-511918	M20	1.5	£82.02	5 days
JBO-511933	M21	1.5	£194.08	5 days
JBO-511948	M22	1.5	£89.92	5 days
JBO-511976	M24	1.5	£96.83	5 days
JBO-511989	M25	1.5	£100.43	5 days
JBO-511997	M26	1.5	£103.63	5 days
JBO-512015	M27	1.5	£106.70	5 days
JBO-512028	M28	1.5	£109.65	5 days
JBO-512083	M30	1.5	£118.42	5 days
JBO-512101	M32	1.5	£120.61	5 days
JBO-512117	M33	1.5	£123.91	5 days
JBO-512130	M34	1.5	£130.48	5 days
JBO-512137	M35	1.5	£129.40	5 days
JBO-512150	M36	1.5	£131.59	5 days
JBO-512162	M38	1.5	£144.74	5 days
JBO-512170	M39	1.5	£154.62	5 days
JBO-512212	M40	1.5	£152.43	5 days
JBO-511843	M18	2	£84.64	5 days
JBO-511923	M20	2	£87.73	5 days
JBO-511955	M22	2	£93.86	5 days
JBO-511981	M24	2	£99.46	5 days
JBO-511992	M25	2	£105.48	5 days
JBO-512003	M26	2	£109.22	5 days
JBO-512020	M27	2	£108.33	5 days
JBO-512032	M28	2	£115.14	5 days
JBO-512089	M30	2	£118.42	5 days
JBO-512106	M32	2	£123.91	5 days
JBO-512120	M33	2	£127.21	5 days
JBO-512133	M34	2	£169.96	5 days
JBO-512142	M35	2	£173.24	5 days
JBO-512153	M36	2	£137.06	5 days
JBO-512165	M38	2	£151.32	5 days
JBO-512173	M39	2	£154.62	5 days
JBO-512216	M40	2	£161.19	5 days
JBO-512094	M30	3	£143.64	5 days
JBO-512124	M33	3	£150.21	5 days
JBO-512156	M36	3	£152.43	5 days
JBO-512175	M39	3	£185.31	5 days
JBO-512217	M40	3	£207.25	5 days
JBO-512197	M4	0.5	£118.42	5 days
JBO-512207	M4.5	0.5	£131.59	5 days
JBO-512240	M5	0.5	£114.03	5 days
JBO-512249	M5.5	0.5	£201.76	5 days
JBO-512274	M6	0.5	£114.03	5 days
JBO-512294	M7	0.5	£119.52	5 days
JBO-512324	M8	0.5	£117.33	5 days
JBO-512351	M9	0.5	£143.64	5 days
JBO-511657	M10	0.5	£131.59	5 days
JBO-514114	M11	0.5	£157.90	5 days
JBO-511700	M12	0.5	£142.55	5 days
JBO-511738	M14	0.5	£159.00	5 days
JBO-511763	M15	0.5	£187.50	5 days
JBO-511787	M16	0.5	£182.03	5 days
JBO-518297	M17	0.5	£226.98	5 days
JBO-513016	M18	0.5	£212.72	5 days
JBO-516782	M20	0.5	£231.36	5 days
JBO-512280	M6	0.75	£74.03	5 days
JBO-512298	M7	0.75	£83.23	5 days
JBO-512327	M8	0.75	£74.13	5 days
JBO-512354	M9	0.75	£92.77	5 days
JBO-511661	M10	0.75	£87.40	5 days
JBO-511683	M11	0.75	£101.87	5 days
JBO-511702	M12	0.75	£96.05	5 days
JBO-513284	M13	0.75	£105.71	5 days
JBO-511742	M14	0.75	£102.98	5 days
JBO-511765	M15	0.75	£109.65	5 days
JBO-511790	M16	0.75	£109.65	5 days
JBO-511814	M17	0.75	£128.29	5 days
JBO-511828	M18	0.75	£116.23	5 days
JBO-511847	M19	0.75	£134.87	5 days
JBO-514211	M20	0.75	£131.59	5 days
JBO-511929	M21	0.75	£152.43	5 days
JBO-511941	M22	0.75	£152.43	5 days
JBO-523226	M23	0.75	£163.39	5 days
JBO-512335	M8	1	£69.08	5 days
JBO-512359	M9	1	£79.29	5 days
JBO-511668	M10	1	£72.50	5 days
JBO-511685	M11	1	£86.52	5 days
JBO-511706	M12	1	£78.84	5 days
JBO-511725	M13	1	£98.59	5 days
JBO-511747	M14	1	£91.35	5 days
JBO-511768	M15	1	£101.87	5 days
JBO-511795	M16	1	£97.16	5 days
JBO-511816	M17	1	£109.65	5 days
JBO-511831	M18	1	£102.76	5 days
JBO-511851	M19	1	£122.80	5 days
JBO-511913	M20	1	£108.33	5 days
JBO-511932 Viewing	M21	1	£139.25	5 days
JBO-511945	M22	1	£120.61	5 days
JBO-511962	M23	1	£148.02	5 days
JBO-511974	M24	1	£129.40	5 days
JBO-511986	M25	1	£144.74	5 days
JBO-511995	M26	1	£149.13	5 days
JBO-512012	M27	1	£154.62	5 days
JBO-512027	M28	1	£159.00	5 days
JBO-513718	M29	1	£178.73	5 days
JBO-512081	M30	1	£161.19	5 days
JBO-512099	M32	1	£164.47	5 days

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