JBO Thread Ring Gauge (GO) - UNC - Right Hand - 3A - No. 4 x 40

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JBO Thread Ring Gauge (GO) - UNC - Right Hand - 3A - No. 4 x 40

SKU:JBO-502391

Specification

Thread Form	UNC
Size	No. 4
Pitch	40
Gauge Type	Ring Gauge (GO)
Thread Direction	Right Hand
Tolerance	3A

£105.48

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5 days estimated lead time — subject to availability

Free delivery over £50 ex VAT

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01732 887334

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

Introducing the JBO Thread Ring Gauge (GO) for UNC threads — Right Hand, 3A, No. 4 x 40. This GO gauge provides precise external thread diameter verification, helping machinists, inspectors, and quality teams quickly determine whether components conform to UNC standards. Built for reliability in busy environments, it supports accurate go/no-go checks across diverse industries.

Precise UNC GO verification: Delivers reliable go/no-go checks for No. 4 x 40 UNC threads with consistent external diameter measurement, speeding up inspections and reducing guesswork.
Durable hardened steel construction: Designed to withstand daily use in demanding shops, resisting wear to maintain long-term accuracy and tool life.
User-friendly inspection design: Enables quick identification of properly threaded components, supporting efficient quality control and minimizing downtime.

By incorporating this GO gauge into your inspection routine, you’ll streamline threaded-part verification, improve consistency across parts, and safeguard production timelines with confidence in every measurement.

Thread Form	UNC
Size	No. 4
Pitch	40
Gauge Type	Ring Gauge (GO)
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.

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 (GO) - Unified

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Product SKU	Size	Pitch	Price	Stock

JBO-502377	No. 1	64	£114.03	5 days
JBO-502382	No. 2	56	£86.19	5 days
JBO-502386	No. 3	48	£103.52	5 days
JBO-502388	No. 4	40	£75.45	5 days
JBO-502392	No. 5	40	£69.08	5 days
JBO-502393	No. 6	32	£58.90	5 days
JBO-502396	No. 8	32	£55.39	5 days
JBO-502379	No. 10	24	£54.28	5 days
JBO-505676	No. 12	24	£63.28	5 days
JBO-502406	1/4	20	£51.88	5 days
JBO-502416	5/16	18	£55.15	5 days
JBO-502413	3/8	16	£60.08	5 days
JBO-502421	7/16	14	£65.48	5 days
JBO-502404	1/2	13	£71.94	5 days
JBO-502425	9/16	12	£99.25	5 days
JBO-502419	5/8	11	£84.43	5 days
JBO-502411	3/4	10	£104.51	5 days
JBO-502423	7/8	9	£127.21	5 days
JBO-502398	1	8	£137.06	5 days
JBO-502401	1 1/8	7	£183.12	5 days
JBO-502400	1 1/4	7	£198.46	5 days
JBO-502403	1 3/8	6	£213.83	5 days
JBO-502399	1 1/2	6	£233.56	5 days
JBO-502402	1 3/4	5	£292.77	5 days
JBO-502409	2	4.5	£335.54	5 days
JBO-502963	2 1/4	4.5	£382.68	5 days
JBO-502410	2 1/2	4	£427.63	5 days
JBO-507588	2 3/4	4	£476.99	5 days
JBO-502378	No. 1	64	£167.77	5 days
JBO-502385	No. 2	56	£128.29	5 days
JBO-502387	No. 3	48	£135.97	5 days
JBO-502391 Viewing	No. 4	40	£105.48	5 days
JBO-502873	No. 5	40	£96.83	5 days
JBO-502394	No. 6	32	£82.35	5 days
JBO-502397	No. 8	32	£77.41	5 days
JBO-502380	No. 10	24	£77.64	5 days
JBO-502381	No. 12	24	£82.14	5 days
JBO-502407	1/4	20	£76.22	5 days
JBO-502417	5/16	18	£81.03	5 days
JBO-502414	3/8	16	£88.06	5 days
JBO-502422	7/16	14	£98.14	5 days
JBO-502405	1/2	13	£107.90	5 days
JBO-503165	9/16	12	£120.61	5 days
JBO-502420	5/8	11	£128.29	5 days
JBO-502797	3/4	10	£156.81	In Stock
JBO-502424	7/8	9	£189.69	5 days
JBO-503166	1	8	£209.44	5 days
JBO-506400	No. 1	64	£163.39	5 days
JBO-506401	No. 2	56	£129.40	5 days
JBO-506402	No. 3	48	£148.02	5 days
JBO-504041	No. 4	40	£112.95	5 days
JBO-506403	No. 5	40	£103.52	5 days
JBO-502395	No. 6	32	£88.15	5 days
JBO-506404	No. 8	32	£83.11	5 days
JBO-503427	No. 10	24	£81.36	5 days
JBO-505677	No. 12	24	£87.84	5 days
JBO-502408	1/4	20	£77.76	5 days
JBO-502418	5/16	18	£82.80	5 days
JBO-502415	3/8	16	£90.25	5 days
JBO-506405	7/16	14	£98.14	5 days
JBO-506406	1/2	13	£107.90	5 days
JBO-506407	9/16	12	£118.42	5 days
JBO-504042	5/8	11	£130.48	5 days
JBO-502412	3/4	10	£156.81	5 days
JBO-506408	7/8	9	£189.69	5 days
JBO-504043	1	8	£209.44	5 days
JBO-506409	1 1/8	7	£245.62	5 days
JBO-505756	1 1/4	7	£268.65	5 days
JBO-506410	1 3/8	6	£299.34	5 days
JBO-506411	1 1/2	6	£317.99	5 days
JBO-502426	No. 1	72	£126.10	5 days
JBO-502436	No. 2	64	£105.26	5 days
JBO-502438	No. 3	56	£104.95	5 days
JBO-502440	No. 4	48	£92.98	5 days
JBO-502442	No. 5	44	£74.55	5 days
JBO-502444	No. 6	40	£71.72	5 days
JBO-502446	No. 8	36	£66.35	5 days
JBO-502430	No. 10	32	£52.75	5 days
JBO-502433	No. 12	28	£63.28	5 days
JBO-502458	1/4	28	£51.97	5 days
JBO-502469	5/16	24	£55.15	5 days
JBO-502466	3/8	24	£60.08	5 days
JBO-502475	7/16	20	£64.82	5 days
JBO-502455	1/2	20	£71.94	5 days
JBO-502481	9/16	18	£77.41	5 days
JBO-502472	5/8	18	£85.65	5 days
JBO-502461	3/4	16	£99.68	5 days
JBO-502478	7/8	14	£117.33	5 days
JBO-502448	1	12	£131.59	5 days
JBO-502453	1 1/8	12	£148.02	5 days
JBO-502452	1 1/4	12	£161.19	5 days
JBO-502454	1 3/8	12	£175.43	5 days
JBO-502451	1 1/2	12	£186.41	5 days
JBO-502427	No. 0	80	£176.54	5 days
JBO-502429	No. 1	72	£148.02	5 days
JBO-502437	No. 2	64	£137.06	5 days
JBO-502439	No. 3	56	£135.97	5 days
JBO-502441	No. 4	48	£121.72	5 days
JBO-502443	No. 5	44	£96.83	5 days
JBO-502445	No. 6	40	£93.10	5 days
JBO-502447	No. 8	36	£85.65	5 days
JBO-502431	No. 10	32	£73.58	5 days
JBO-502435	No. 12	28	£82.14	5 days
JBO-502459	1/4	28	£72.81	5 days
JBO-502470	5/16	24	£77.10	5 days
JBO-502467	3/8	24	£84.22	5 days
JBO-502476	7/16	20	£90.46	5 days
JBO-502456	1/2	20	£100.55	5 days
JBO-502482	9/16	18	£108.45	5 days
JBO-502473	5/8	18	£119.52	5 days
JBO-502463	3/4	16	£139.25	5 days
JBO-502479	7/8	14	£164.47	5 days
JBO-502449	1	12	£183.12	5 days
JBO-502757	1 1/8	12	£207.25	5 days
JBO-503207	1 1/4	12	£225.87	5 days
JBO-503209	1 3/8	12	£245.62	5 days
JBO-502768	1 1/2	12	£264.27	5 days
JBO-506438	No. 0	80	£176.54	5 days
JBO-506441	No. 1	72	£148.02	5 days
JBO-506445	No. 2	64	£137.06	5 days
JBO-506448	No. 3	56	£135.97	5 days
JBO-506449	No. 4	48	£121.72	5 days
JBO-506452	No. 5	44	£96.83	5 days
JBO-506453	No. 6	40	£93.10	5 days
JBO-506454	No. 8	36	£85.65	5 days
JBO-502432	No. 10	32	£76.44	5 days
JBO-506455	No. 12	28	£83.67	5 days
JBO-502460	1/4	28	£72.81	5 days
JBO-502471	5/16	24	£81.03	5 days
JBO-502468	3/8	24	£84.22	5 days
JBO-502477	7/16	20	£92.98	5 days
JBO-502457	1/2	20	£104.72	5 days
JBO-502483	9/16	18	£116.23	5 days
JBO-502474	5/8	18	£119.52	5 days
JBO-502464	3/4	16	£139.25	5 days
JBO-502480	7/8	14	£164.47	5 days
JBO-502450	1	12	£183.12	5 days
JBO-503127	1 1/8	12	£207.25	5 days
JBO-506456	1 1/4	12	£225.87	5 days
JBO-506457	1 3/8	12	£245.62	5 days
JBO-505736	1 1/2	12	£264.27	5 days
JBO-501299	No. 12	32	£74.79	5 days
JBO-501313	1/4	32	£74.79	5 days
JBO-501326	5/16	32	£80.16	5 days
JBO-501323	3/8	32	£85.20	5 days
JBO-501329	7/16	2	£90.46	5 days
JBO-501310	1/2	28	£94.52	5 days
JBO-501334	9/16	24	£104.60	5 days
JBO-501327	5/8	24	£111.84	5 days
JBO-501316	11/16	24	£120.61	5 days
JBO-501319	3/4	20	£127.21	5 days
JBO-501317	13/16	20	£133.78	5 days
JBO-501333	7/8	20	£144.74	5 days
JBO-501318	15/16	20	£155.70	5 days
JBO-501300	1	20	£163.39	5 days
JBO-501305	1 1/16	18	£173.24	5 days
JBO-501303	1 1/8	18	£179.84	5 days
JBO-501307	1 3/16	18	£189.69	5 days
JBO-501302	1 1/4	18	£202.87	5 days
JBO-501308	1 5/16	18	£213.83	5 days
JBO-501306	1 3/8	18	£225.87	5 days
JBO-501309	1 7/16	18	£236.85	5 days
JBO-501301	1 1/2	18	£248.90	5 days
JBO-506769	1 9/16	18	£266.46	5 days
JBO-506489	No. 12	32	£105.71	5 days
JBO-501315	1/4	32	£105.71	5 days
JBO-506490	5/16	32	£116.23	5 days
JBO-506491	3/8	32	£121.72	5 days
JBO-501332	7/16	2	£127.21	5 days
JBO-503778	1/2	28	£133.78	5 days
JBO-505871	9/16	24	£145.83	5 days
JBO-503138	5/8	24	£167.77	5 days
JBO-506492	11/16	24	£178.73	5 days
JBO-501322	3/4	20	£188.61	5 days
JBO-506493	13/16	20	£202.87	5 days
JBO-506494	7/8	20	£218.21	5 days
JBO-506495	15/16	20	£233.56	5 days
JBO-504056	1	20	£244.52	5 days
JBO-502570	1/4	36	£207.25	5 days
JBO-502546	1	32	£421.06	5 days
JBO-502576	11/16	16	£350.89	5 days
JBO-502580	13/16	16	£307.02	5 days
JBO-502601	7/8	16	£313.60	5 days
JBO-502545	1	16	£350.89	5 days
JBO-542688	1 1/16	16	£370.62	5 days
JBO-502561	1 3/16	16	£407.90	5 days
JBO-505372	1	14	£288.38	5 days
JBO-502552	1 1/16	12	£321.28	5 days
JBO-502560	1 3/16	12	£364.04	5 days
JBO-502563	1 5/16	12	£359.66	5 days
JBO-502562	1 5/8	12	£459.45	5 days
JBO-502554	1 3/4	12	£441.89	5 days
JBO-502565	1 7/8	12	£482.48	5 days
JBO-502584	2	12	£490.14	5 days
JBO-503417	1 1/8	8	£357.46	5 days
JBO-502549	1 1/4	8	£359.66	5 days
JBO-552099	1 3/8	8	£387.07	5 days
JBO-502547	1 1/2	8	£463.83	5 days
JBO-502924	1 5/8	8	£486.86	5 days
JBO-502556	1 3/4	8	£552.65	5 days
JBO-503356	2	8	£596.51	5 days
JBO-504210	No. 2	56	£167.77	5 days
JBO-503593	No. 4	40	£139.25	5 days
JBO-505569	No. 6	32	£120.61	5 days
JBO-501415	No. 8	32	£111.84	5 days
JBO-547026	No. 10	24	£111.84	5 days
JBO-547027	1/4	20	£111.84	5 days
JBO-547028	5/16	18	£111.84	5 days
JBO-507449	3/8	16	£116.23	5 days
JBO-554996	7/16	14	£148.02	5 days
JBO-547029	No. 4	48	£143.64	5 days
JBO-505347	No. 6	40	£117.33	5 days
JBO-501418	No. 8	36	£108.02	5 days
JBO-501417	No. 10	32	£94.30	5 days
JBO-504244	No. 12	28	£108.02	5 days
JBO-501419	1/4	28	£94.30	5 days
JBO-501422	5/16	24	£98.80	5 days
JBO-501421	3/8	24	£106.58	5 days
JBO-501424	7/16	20	£116.23	5 days
JBO-502986	1/2	20	£128.29	5 days
JBO-501425	9/16	18	£135.97	5 days
JBO-501423	5/8	18	£153.51	5 days
JBO-501420	3/4	16	£176.54	5 days
JBO-503651	7/8	14	£207.25	5 days
JBO-503703	1	12	£233.56	5 days
JBO-547575	1/4	28	£151.32	5 days
JBO-503866	3/8	24	£171.05	5 days
JBO-547590	1/2	20	£206.14	5 days