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VCOIL Plug Gauge (D/E) - UNC (STI) - Heli Coil Gauge - Right Hand - 3B - 1/4 x 20
| Thread Form | UNC (STI) |
| Size | 1/4 |
| Pitch | 20 |
| Gauge Type | Plug Gauge (D/E) |
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The ones our customers buy most.Description
Precision VCOIL Plug Gauge for UNC 1/4 x 20 internal threads, designed for quality-focused shops that install Helicoil inserts. It combines Go/No-Go testing with ANSI/ASME thread standards to ensure threads meet exact specifications.
- Thread system and size: UNC (STI) 1/4 x 20, Right Hand, 3B tolerance class, tailored for Helicoil insert applications.
- Go/No-Go design: A single gauge that includes both go and no-go ends; the go end should screw into the thread by hand, and the scrap/no-go end should not turn more than two full turns.
- Standards compliance: Manufactured and assessed according to ANSI/ASME thread systems, with a reference temperature of 20°C for parts and gauges.
- Scrap indication: The scrap side is clearly marked, enabling quick identification during inspection.
- Helicoil compatibility: Specifically configured for validating internally threaded helicoil insert configurations to ensure proper fit and function.
- Usage convenience: Designed for reliable, on-the-spot verification on the shop floor, reducing guesswork during assembly and maintenance.
Using this gauge helps ensure internal threads are within spec, supporting consistent part fit, reducing rework, and speeding up quality checks during production or repair workflows. It’s a trusted tool for technicians working with UNC 1/4-20 threads and Helicoil inserts, providing clear go/no-go results and durable, repeatable measurements.
Part Numbers
- Protool Part Number
- TC-19907
- Brand
- VCOIL
- Category
- Gauge
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.
Full Range: VCOIL Plug Gauges UNC (STI)
View full collection →You are viewing TC-19907. Click any other SKU to view its full details.
| Product SKU | Size | Pitch | Price | Stock | Order |
|---|---|---|---|---|---|
| TC-19800 | No. 2 | 56 | £101.37 | 7 days | |
| TC-19801 | No. 4 | 40 | £101.37 | 7 days | |
| TC-19802 | No. 5 | 40 | £101.37 | In Stock | |
| TC-19803 | No. 6 | 32 | £101.37 | 7 days | |
| TC-19804 | No. 8 | 32 | £103.35 | 7 days | |
| TC-19805 | No. 10 | 24 | £103.35 | In Stock | |
| TC-19806 | No. 12 | 24 | £95.40 | In Stock | |
| TC-19807 | 1/4 | 20 | £99.38 | 7 days | |
| TC-19808 | 5/16 | 18 | £99.38 | In Stock | |
| TC-19809 | 3/8 | 16 | £115.28 | In Stock | |
| TC-19810 | 7/16 | 14 | £108.65 | In Stock | |
| TC-19811 | 1/2 | 13 | £147.08 | 7 days | |
| TC-19812 | 9/16 | 12 | £156.35 | In Stock | |
| TC-19813 | 5/8 | 11 | £174.90 | In Stock | |
| TC-19814 | 3/4 | 10 | £184.18 | In Stock | |
| TC-19815 | 7/8 | 9 | £193.45 | 7 days | |
| TC-19816 | 1 | 8 | £247.78 | 7 days | |
| TC-19817 | 1.1/8 | 7 | £266.33 | 7 days | |
| TC-19818 | 1.1/4 | 7 | £303.43 | 7 days | |
| TC-19819 | 1.3/8 | 6 | £212.00 | 7 days | |
| TC-19820 | 1.3/8 | 6 | £212.00 | 7 days | |
| TC-19821 | 1.1/2 | 6 | £238.50 | 7 days | |
| TC-19822 | 1.1/2 | 6 | £238.50 | 7 days | |
| TC-19900 | No. 2 | 56 | £121.90 | 7 days | |
| TC-19901 | No. 4 | 40 | £121.90 | 7 days | |
| TC-19902 | No. 5 | 40 | £121.90 | 7 days | |
| TC-19903 | No. 6 | 32 | £121.90 | 7 days | |
| TC-19904 | No. 8 | 32 | £124.55 | 7 days | |
| TC-19905 | No. 10 | 24 | £124.55 | 7 days | |
| TC-19906 | No. 12 | 24 | £115.28 | 7 days | |
| TC-19907 Viewing | 1/4 | 20 | £119.25 | 7 days | |
| TC-19908 | 5/16 | 18 | £119.25 | 7 days | |
| TC-19909 | 3/8 | 16 | £137.80 | 7 days | |
| TC-19910 | 7/16 | 14 | £131.18 | 7 days | |
| TC-19911 | 1/2 | 13 | £176.23 | 7 days | |
| TC-19912 | 9/16 | 12 | £188.15 | 7 days | |
| TC-19913 | 5/8 | 11 | £209.35 | 7 days | |
| TC-19914 | 3/4 | 10 | £221.28 | 7 days | |
| TC-19915 | 7/8 | 9 | £231.88 | 7 days | |
| TC-19916 | 1 | 8 | £298.13 | 7 days | |
| TC-19917 | 1.1/8 | 7 | £319.33 | 7 days | |
| TC-19918 | 1.1/4 | 7 | £364.38 | 7 days | |
| TC-19919 | 1.3/8 | 6 | £254.40 | 7 days | |
| TC-19920 | 1.3/8 | 6 | £254.40 | 7 days | |
| TC-19921 | 1.1/2 | 6 | £286.20 | 7 days | |
| TC-19922 | 1.1/2 | 6 | £286.20 | 7 days |
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