JBO Thread Ring Gauge (NoGo) - UNC - Left Hand - 2A - 5/16 x 18

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JBO Thread Ring Gauge (NoGo) - UNC - Left Hand - 2A - 5/16 x 18

SKU:JBO-501090

Specification

Thread Form	UNC
Size	5/16
Pitch	18
Gauge Type	Ring Gauge (NoGo)
Thread Direction	Left Hand
Tolerance	2A

£82.80

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

Pay in 3 interest-free instalments. No extra cost if paid on time. 18+ only.
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01732 887334

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

The JBO Thread Ring Gauge (NoGo) for UNC Left Hand 2A, 5/16 x 18 is a precision inspection tool used to verify external thread diameters on fasteners, fittings, and machined components. Designed for manufacturing, automotive, and aerospace environments, it enables quick go/no-go checks to confirm compliance with Unified Thread Standards and specifications. The No-Go feature instantly flags non-conforming threads, helping prevent mismatches and costly rework. Crafted from hardened steel, it is built to withstand regular use in demanding shop floors.

No-Go design for fast conformance checks: Quickly identify non-conforming threads during inspection, reducing downtime and preventing incorrect assemblies.
Hardened steel construction for durability: Built to withstand daily use in busy workshops and rigorous QA processes while maintaining measurement accuracy.
UNC Left-Hand 5/16 x 18, 2A precision specification: Ensures consistent, repeatable external-thread measurements aligned with Unified standards.

Using this gauge simplifies your quality workflow by providing a reliable, repeatable method to verify thread size and fit. It saves inspection time, lowers the risk of incorrect parts entering assemblies, and helps your team meet tight production schedules with greater confidence.

Thread Form	UNC
Size	5/16
Pitch	18
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.

Bill

★★★★★

first place we look

honest about stock and prices are competitive.

Phil

★★★★★

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 .

Graham

★★★★★

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.

Jeremy

Full Range: JBO Thread Ring Gauges (NoGo) - Unified

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Product SKU	Size	Pitch	Price	Stock

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 Viewing	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	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