Terminal Size Chart: JIS vs DIN vs AWG (mm² Conversion Guide)

If you buy terminals and crimping tools for more than one market, you have probably seen the same wire described three different ways: 5.5 mm² on a Japanese terminal, 6 mm² on a European lug and 10 AWG on an American one. They are close — but not identical — and choosing the wrong crimp size is one of the most common causes of loose, overheating connections.

This guide explains the three sizing systems, gives you a conversion chart, and shows how to choose a crimping tool that matches the terminals you sell or use.

1. The three sizing systems

System	Used mainly in	How sizes are written	Examples
JIS (Japanese Industrial Standard)	Japan, Taiwan, much of Asia	Conductor cross-section in mm², using JIS steps	1.25, 2, 3.5, 5.5, 8, 14, 22, 38, 60, 80, 100, 150
DIN / IEC (metric)	Europe and most metric markets	Conductor cross-section in mm², using IEC steps	1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150
AWG / MCM	North America	Gauge number (larger number = smaller wire); MCM (kcmil) above 4/0	16, 14, 12, 10, 8, 6, 4, 2, 1/0 … 4/0, 250 MCM

JIS and DIN are both in mm², but they use different size steps — for example JIS 5.5 mm² versus DIN 6 mm², or JIS 38 mm² versus DIN 35 mm². A terminal and a crimp die must be made for the same step.

2. AWG to mm² conversion chart with nearest JIS and DIN sizes

AWG / MCM	Conductor area (mm²)	Nearest JIS terminal (mm²)	Nearest DIN terminal (mm²)
22	0.33	1.25 (covers 22–16 AWG)	0.5
20	0.52	1.25	0.5
18	0.82	1.25	0.75 / 1
16	1.31	1.25	1.5
14	2.08	2	2.5
12	3.31	3.5	4
10	5.26	5.5	6
8	8.37	8	10
6	13.3	14	16
4	21.2	22	25
2	33.6	38	35
1/0	53.5	60	50
2/0	67.4	70	70
3/0	85.0	80	95
4/0	107	100	120
250 MCM	127	—	120
300 MCM	152	150	150

The “nearest” sizes are a practical guide, not an official equivalence. Always follow the size range printed by the terminal manufacturer.

3. Insulated terminal color codes

Pre-insulated terminals use a simple color code that is the same across most markets:

Color	AWG range	Metric range (mm²)	Typical JIS size
Red	22–16	0.5–1.5	1.25
Blue	16–14	1.5–2.5	2
Yellow	12–10	4–6	5.5

4. How to read terminal markings

JIS terminals are usually marked with type, wire size and stud size. For example, R5.5-6 means a ring (R) terminal for 5.5 mm² wire and an M6 stud; Y indicates a fork (spade) terminal.
DIN cable lugs are usually marked with the cross-section and stud size, for example 35-10 for a 35 mm² lug with an M10 hole.
AWG terminals are marked with the wire gauge range, for example 12-10.

5. Why the crimp size must match

Die too large → the barrel is not compressed enough; the conductor can pull out, and contact resistance rises, which leads to heat.
Die too small → over-compression can crack the barrel or cut conductor strands.
Different standard → a DIN 35 mm² lug in a JIS 38 mm² die (or the reverse) may look close but will not give a correct crimp.

Use the crimping tool position that matches the terminal size, and check the crimp: the conductor should not move when pulled by hand, and the barrel should not be cracked.

Indent or hexagonal crimp?

Indent (point) crimping presses a single indent into the barrel and is common for terminals and smaller lugs. Hexagonal crimping compresses the lug evenly from six sides, creating a larger contact area — it is often preferred for cable lugs where a reliable, low-resistance connection is critical.

6. Choosing a crimping tool by terminal size

Each THK crimping tool lists its JIS, DIN and AWG sizes, so you can match it to the terminals in your market:

Terminal sizes you crimp	Crimp type	THK models
Small terminals, JIS 1.25–2 / DIN 1.5–2.5 / AWG 22–14	Indent	VTC-02
Up to JIS 5.5 / DIN 6 / AWG 10	Indent	VTC-5.5
Up to JIS 8–14 / DIN 10–16 / AWG 8–6	Indent	VTC-08, VTC-14
JIS 5.5–38 / DIN 6–50 / AWG 12–1/0	Indent	VTC-25, VTC-38, VTC-38N
Cable lugs up to JIS 60–80 / AWG 3/0	Indent	VTC-60, VTC-80
Cable lugs up to JIS 100–150 / DIN 120–150 / AWG 4/0–300 MCM	Indent	VTC-100, VTC-120, VTC-150
DIN 6–16 or 6–50 mm² / AWG 10–1/0	Hexagonal	VTC-25H, VTC-50H
Cable lugs up to 120–150 mm² / AWG 4/0–300 MCM	Hexagonal	VTC-120H, VTC-150H

See the exact sizes of every model on our crimping tools page or in the product catalog (PDF).

Need crimping tools for your market?

Tell us which terminal standard your customers use (JIS, DIN or AWG), the size range and the quantity — we will recommend the right models and send a quotation, usually within 1–2 business days. THK Cutters manufactures crimping tools, hexagonal crimping tools and cable cutters in Taiwan, with OEM and private label available.

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