16-20mm 0.63-0.79" Three Point Internal Bore Micrometer - 3227 Series (Insize)

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16-20mm 0.63-0.79" Three Point Internal Bore Micrometer - 3227 Series (Insize)

SKU:3227-20

Specification

Range (mm)	16-20
Range (inch)	0.63-0.79
Setting Ring	16mm (included)
b	6
Accuracy	Â±0.004mm
Graduation	0.03mm

£219.13

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4–5 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

The Insize 3227 Three-Point Internal Bore Micrometer is a precision measuring tool designed for accurate inside-diameter checks. With three-point contact, it delivers stable, repeatable readings across bore walls, making it ideal for engineers, machinists, quality inspectors, and serious hobbyists who need dependable internal measurements in tight tolerances.

This model covers bore sizes from 16–20 mm (0.63–0.79") and can measure up to 300 mm. It features a fine 0.005 mm graduation, carbide measuring faces for wear resistance, a ratchet stop to ensure consistent contact pressure, and it is supplied with a setting ring for quick, reliable zeroing. These features combine to provide long-life reliability in demanding workshop environments.

Three-point internal measurement: achieves stable, repeatable readings by evenly distributing contact pressure around the bore, reducing eccentricity errors.
Carbide measuring faces: designed for wear resistance and longevity, maintaining accuracy even after frequent use in metalworking environments.
Ratchet stop with setting ring: delivers consistent touch and easy zeroing, minimizing user variation and speeding up repetitive inspections.

In use, this bore micrometer helps you quickly verify internal diameters with confidence, reducing rework and downtime. Its rugged construction and precise graduation enable reliable results across a wide range of bore sizes, making it a trusted addition to any inspection bench or machine shop workflow.

Range (mm)	16-20
Range (inch)	0.63-0.79
Setting Ring	16mm (included)
b	6
Accuracy	Â±0.004mm
Graduation	0.03mm
Read Out	Analogue
IP Rating	IP65
mm or Inch	mm\|inch
Data Output	No
Individual or Set	Individual

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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Staff are very helpful and interested in providing a good service making us the customer feel valued.

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first place we look

honest about stock and prices are competitive.

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Staff are very helpful and polite.Goods that were in stock were dispatched same day and back orders were quick in coming through .

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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: Three Point Internal Bore Micrometers - 3227 Series (Insize)

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You are viewing 3227-20. Click any other SKU to view its full details.

Product SKU	Metric Range (mm)	Metric Range (Inch)	Ip Rating	mm or Inch	Price	Stock

3227-8	46240	0.24-0.31	IP65	mm\|inch	£273.39	4-5 days
3227-10	46303	0.31-0.39	IP65	mm\|inch	£273.39	4-5 days
3227-12	46366	0.39-0.47	IP65	mm\|inch	£273.39	4-5 days
3227-16	42705	0.47-0.63	IP65	mm\|inch	£219.13	4-5 days
3227-20 Viewing	16-20	0.63-0.79	IP65	mm\|inch	£219.13	4-5 days
3227-25	20-25	0.79-0.98	IP65	mm\|inch	£285.91	4-5 days
3227-30	25-30	0.98-1.18	IP65	mm\|inch	£285.91	4-5 days
3227-40	30-40	1.18-1.57	IP65	mm\|inch	£325.57	4-5 days
3227-50	40-50	1.57-1.97	IP65	mm\|inch	£354.78	4-5 days
3227-63	50-63	1.97-2.48	IP65	mm\|inch	£393.39	4-5 days
3227-75	62-75	2.44-2.95	IP65	mm\|inch	£408.00	4-5 days
3227-88	75-88	2.95-3.46	IP65	mm\|inch	£427.83	4-5 days
3227-100	87-100	3.43-3.94	IP65	mm\|inch	£449.74	4-5 days
3227-125	100-125	3.94-4.92	IP65	mm\|inch	£563.48	4-5 days
3227-150	125-150	4.92-5.91	IP65	mm\|inch	£636.52	4-5 days
3227-175	150-175	5.91-6.89	IP65	mm\|inch	£705.39	4-5 days
3227-200	175-200	6.89-7.87	IP65	mm\|inch	£814.96	4-5 days
3227-225	200-225	7.87-8.86	IP65	mm\|inch	£1,039.30	4-5 days
3227-250	225-250	8.86-9.84	IP65	mm\|inch	£1,173.91	4-5 days
3227-275	250-275	9.84-10.83	IP65	mm\|inch	£1,361.74	4-5 days
3227-300	275-300	10.83-11.81	IP65	mm\|inch	£1,581.91	4-5 days