JST Connectors Q&A

Table of Content

What are JST Connectors?

It’s a misconception that JST connector is a single connector specification.

JST is short for JAPANESE SOLDERLESS TERMINALS. It’s a Japanese connector manufacturer. JST makes a wide range of connectors for a variety of uses.

Thus JST connectors stands for connectors made by JST. NOT a single connector specification.

Even if you say JST 2.0mm connector, it doesn’t identify a single connector specification. JST PUD, PA, and PH series are 2.0mm connectors.

To identify a JST connector, you should either use its unique part number or a specific description with series, name, gender, circuit name, etc. 

Related article: Measure JST Connector Pitch.

Let’s take the following connector for example. You should use its part number “B10B-PUDSS-1” or a description like ‘JST PUD vertical 10 pin header’.

jst b10b-pudss-1

What is the difference between JST PH and JST SH?

JST PH and JST SH have differences in terms of pitch, circuit size, current rating, voltage rating, board connector types, and lock feature. Let’s check one by one.


Pitch size is a primary distinguishing factor between JST PH and JST SH connectors. JST PH connectors is 2.0mm (0.079 inches) pitch, while JST SH is 1.0mm (0.039 inches) pitch. This means that JST SH connectors have a higher pin density and are suitable for use in smaller form factor devices.

Circuit size

JST PH connectors are available in circuit sizes ranging from 2 to 16 contacts, whereas JST SH connectors can have anywhere from 2 to 15 contacts, and 20 contacts.

The current rating and voltage rating

Current rating of JST PH connector is 2A per contact, and the voltage rating is 100V AC/DC. Making it suitable for use in applications with higher power requirements. Correspondingly, JST SH connector is 1A, and 50V AC/DC. Which is suitable for low-power applications.

Board connector types

JST PH connectors are available in both SMT and through-hole types, making them well-suited to a variety of applications. While JST SH connectors have only SMT type, which limits their use in through-hole PCB designs. However, JST SH connectors’ smaller pitch size makes them ideal for use in high-density PCB designs that require small and compact connectors.

Lock feature

JST PH connectors feature a friction lock mechanism, which helps to keep the connection between female and male secure and stable. This makes them ideal for applications where vibration or other external factors could potentially cause the connection to become loose. In contrast, JST SH connectors do not feature a lock mechanism, making them easier to connect and disconnect but also less secure than JST PH connectors. Therefore, designers need to carefully consider the specific requirements of their application when selecting a connector with or without a locking mechanism.

What does a JST connector look like?

Common JST wire-to-board, wire-to-wire connectors look rectangular in 2D and cubic in 3D. They are normally in white, black, or beige.

jst connector on PCB
jst connectors on PCB
alternative connectors
common JST headers
jst xhr 2pin
JST XHR 2 pin with cable

What are JST connectors used for?

JST connectors are used widely across a spectrum of electrical applications. Mainly in consumer products for rechargeable battery packs, battery balancers, battery eliminator circuits, etc.

Where are JST connectors made?

JST connectors are made in its plants in Japan, China, the USA, Indonesia, South Korea, and Malaysia.

Are JST connectors waterproof?

JST has a wide range of connectors. There are waterproof connectors. Following are JST waterproof connectors.

JWPF connector wire to wire
JWPF wire to wire
JWPF connector wire to board
JWPF wire to board
MWP connector
MWP connector
WPK connector
WPK connector
EVZ2 connector
EVZ2 connector
MWT connector
MWT connector
UB connector Micro USB
UB connector Micro USB
UBC connector
UBC connector
JFA connector
JFA connector
WPJ connector (wrie to board)
WPJ wrie to board
WPJ connector wire to wire
WPJ wire to wire
JWPS connector (wire to wire)
JWPS wire to wire
JWPS connector (wire to board)
JWPS wire to board

How do I know what JST connectors I have?

To identify a JST connector, we need to know the pitch of the connector, and the look of it.

Pitch is the distance between the centers of two neighboring circuits. For example, the JST PH series is a 2.0 mm pitch connector system.

When we say to measure a JST connector size, we are talking about measuring the pitch of the connector.

Related article: measure JST connector pitch.

Please understand that there are different series of JST connectors in the same pitch. For example, both the JST EH series and the JST XH series are 2.50 mm pitch connectors. So you can’t identify a JST connector only by its pith. But we can see that JST XH series housing has two symmetric spoon-like locks.

jst XHR

How to solder a JST connector?

JST connector is designed to crimp, not to solder. We strongly recommend you crimp instead of solder. Following is a video from Hugh Elliott soldering wires onto JST XH terminals. But later he bought a proper crimper to finish the work quicker, easier and cleaner.

How terminals connect with contacts of header?

When you insert crimped terminals into a header, the contacts of the header change the shapes of the crimped terminals. Thus there is a friction force between the contacts of the header and terminals.

terminals connection

The red dots are connection points between the contacts of the header and terminals. 

contact of header

Do JST connectors lock?

Some JST connectors have lock features and some don’t.

There are three types of locking features.

1. friction locking feature (ACH, EH, PH, XH).

friction lock feature


2. secure locking feature (GH, GHD, ZE, ZPD, JWPF, PA, PUD, XA, SL, VH, EL, YL, NV, VL).

secure lock

friction lock vs secure lock

3. inertia locking feature.

inertia lock


How to unplug a JST connector (without damaging it)?

With the understanding of how terminals connect with contacts of header. We know that when the wires are crimped correctly, pulling the crimped wires to disconnect the terminals from the contacts of the header won’t break the connections between the terminals and wires.

Now let’s unplug different types of JST connectors.

  • If the connector has a secure lock or inertia lock, you should unlock it before pulling it. You can easily unplug a connector with a secure lock or inertia lock, as the lock itself is intended for fingers to latch onto.
  • For connector housings without hook lock but with edges extending past the connection holes, it should be easy to latch onto with your fingernails and then pull the housing from the header.
    edges connector housing
  • If the connector is without a lock feature or with a friction lock, and no edges to latch onto, just pull it by the wires all the way down by the connector itself. Make sure you have the same amount of tension on all wires to avoid damage to any terminals or connections between terminals and wires. The plastic is very soft, and it’s designed for being unplugged this way (the wires should be crimped correctly).

What are the different types of JST connectors?

Please check another article we wrote: Comment JST connector types.

Are JST and Molex the same?

First, let’s understand the basics of JST and Molex.


In electronics, JST stands for Japan Solderless Terminals. Japan Solderless Terminals (JST) is a global manufacturer of interconnection products such as connectors, cables, wires, optoelectronics, and more.


Molex LLC is a manufacturer of electronic, electrical, and fiber optic connectivity systems. Molex offers over 100,000 products across various industries, including data communications, medical, industrial, automotive, and consumer electronics.

A JST connector series and a Molex connector series are NOT the same. Even if they are of the same pitch (pin-to-pin distance).

For example, the JST GH connector and the Molex PicoBlade connector are both 1.25 mm (0.049 in) pitch. But you can’t use a JST female connector with a Molex PicoBlade male connector. And vice versa.

JST GH Connector
1251 molex picoblade series
Molex PicoBlade Connector

Only use the female and male connectors in the same series.

It’s easy to identify JST GH and Molex PicoBlade.

JST GH housing has a secure locking feature, which Molex PicoBlade housing doesn’t.

Molex 51021-0400
Molex 51021-0400

JST GH header has a hole for locking, which Molex PicoBlade header doesn’t.

Molex 53398-0571
Molex 53398-0571

If you have you have a problem identifying a connector, please read another article.

How to measure JST connector size?

If you still can’t identify a connector, please leave a comment.

How many amps can a JST connector handle?

JST has a wide range of connectors. Please check the amps of common JST connectors in another article.

Common JST Connector Types

Are JST connectors standard?

JST connectors are widely used in the electronics industry and have become a de facto standard for wire-to-board and wire-to-wire applications.

Many manufacturers of electronic devices and components use JST connectors due to their reliability, durability, and versatility. As a result, JST connectors are considered a standard connector in many applications, especially in the areas of consumer electronics, automotive, and industrial equipment.

However, it is important to note that JST connectors are not the only standard connectors available, and other connector types may be more suitable for specific applications.

What is the smallest JST connector?

The JST SH series is known for its small size and high pin density. It is 1.0mm (0.039 inches) pitch and is available from 2 to 15 contacts. Therefore, the smallest JST connector would be the JST SH connector with 2 contacts, which is commonly used in small and compact electronic devices that require high-density interconnections.

1002 JST SH Series Connector
JST SH series
JST SH 2 pin Housing

JST ACH (1.2mm pitch) and JST SUR (0.8mm pitch) is also very small. However, the JST SH series is the most common one.

1201 1.20mm JST ACH Connector
JST ACH Connector
0801 JST SUR Connector
JST SUR Connector


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