JST Connector Comparison: PH vs XH vs SH vs ZH vs GH for Board-to-Wire Applications

Selecting between JST's PH, XH, SH, ZH, and GH board-to-wire series comes down to four engineering constraints:

Key Takeaways

• Pitch and current scale together — PH (2.00 mm) and XH (2.50 mm) handle 2–3 A per circuit, while SH (1.00 mm), GH (1.25 mm), and ZH (1.50 mm) all cap at 1 A per circuit at 50 V AC/DC.
• JST XH is the workhorse for general industrial board-to-wire — 3 A per circuit at 250 V across AWG 22–30 makes it the default below 3 A and 85 °C ambient.
• SH is the only friction-fit series — PH, XH, ZH, and GH have positive latches; SH retains by contact spring force alone and should not be specified for vibration-rated applications.
• IPC/WHMA-A-620 Class 2 acceptance requires JST-published crimp-height tolerance, visible insulation crimp wings, and pull-force per IPC-620 Table 19-2 — applies equally to all five series.
• Sub-1.5 mm pitch forces an AWG and cost penalty — SH and GH require AWG 28–32 wire and tighter crimp tooling, raising assembly cost relative to PH or XH.

Engineering rule of thumb: For board-to-wire applications under 3 A with available board space, default to JST XH — it carries the highest current per circuit, accepts the widest AWG range, and has the most mature crimp-tooling and aftermarket-terminal ecosystem of the five series.

Pitch Selection and PCB Footprint Constraints

Pitch defines the center-to-center distance between contacts and is the first selection axis because it constrains both PCB real estate and the practical AWG range a connector can accept. JST's board-to-wire series scale from 1.00 mm (SH) up to 2.50 mm (XH), with intermediate options at 1.25 mm (GH), 1.50 mm (ZH), and 2.00 mm (PH).

A 10-circuit XH header occupies roughly 25 mm of PCB edge; the same count in SH occupies 10 mm. That 15 mm delta justifies the smaller pitch in handheld instruments, board-stack assemblies, and dense control PCBs. The tradeoff: smaller pitch forces smaller terminals, finer AWG, and lower current per circuit.

For board-to-wire applications where assembly serviceability matters more than density — industrial controls, lab equipment, manufacturing test fixtures — PH and XH remain the default. The 2.0–2.5 mm pitch is large enough for routine field rework with hand crimpers and standard release tooling.

Current, Voltage, and Derating Across the Five Series

Per JST published datasheets, current ratings split cleanly into two tiers. PH carries 2 A per circuit at 100 V AC/DC. XH is the highest-current series at 3 A per circuit and 250 V AC/DC. SH, ZH, and GH all rate at 1 A per circuit and 50 V AC/DC.

These ratings are single-circuit maxima at +25 °C ambient. When all circuits carry rated current simultaneously, expect 20–30% derating from adjacent-circuit thermal coupling. Operating temperature across all five series is -25 °C to +85 °C.

For loads above 3 A, JST's larger-pitch series (VH at 3.96 mm) or alternative families like Molex KK or Mini-Fit Jr. are appropriate. Stacking multiple XH circuits in parallel is a common workaround but is not supported by JST current-sharing data — pin contact resistance variance can cause unequal current distribution and localized overheating.

Locking Mechanisms: Latched vs. Friction-Fit

PH, XH, ZH, and GH all use a positive latch — a flexible housing tab that engages a feature on the mating header and must be depressed to disengage, providing measurable retention against vibration and accidental snag loads.

SH is friction-fit only. It has no positive locking feature; mating retention depends on the contact spring force alone. This is the single most common selection trap when miniaturizing — SH gives the smallest pitch but disqualifies the connector for vibration-rated applications without external retention.

For automotive, mobile equipment, and any application subject to MIL-STD-810 or IEC 60068-2-6 vibration testing, specify a latched series. If 1.0 mm pitch is non-negotiable, SH must be combined with potting compound, board-level conformal coating around the housing, or mechanical capture features built into the enclosure.

Wire AWG Compatibility and IPC/WHMA-A-620 Crimp Validation

Wire range follows pitch: PH and XH accept AWG 22–30, ZH and GH accept AWG 26–32, SH accepts AWG 28–32. JST publishes per-series crimp-height specifications in their crimping instruction documents — the controlling reference for any custom cable assembly using these terminals.

Per IPC/WHMA-A-620 crimp acceptance, a Class 2 build requires:

• Visible insulation crimp wings folded into the wire jacket
• Wire conductor visible at the inspection window with no missed strands
• Crimp height within JST's published tolerance band — typically ±0.05 mm for SH/GH, ±0.10 mm for PH/XH
• Pull-force values meeting AWG-specific minimums in IPC-620 Table 19-2

Class 3 builds (medical, aerospace, mil-spec) add micro-section validation per IPC-A-610, requiring at least four contact points between the crimp barrel and conductor strands and no fractured wires. Crimp pull-force testing and micro-section analysis on first articles and at lot intervals is required for Class 3 acceptance.

Application Mapping: Where Each Series Fits

XH dominates general industrial board-to-wire — power input on PLCs, motor encoder breakouts, fan headers in cabinet-mount equipment. The 3 A rating covers most peripheral loads, and the 250 V rating clears NEC requirements for switched 120 V AC accessory circuits.

PH is common in compact industrial sensors and battery interconnect — its 2.0 mm pitch fits dense PCBs while preserving 2 A capacity. Lithium battery packs frequently use PH for cell balance and discharge connections in custom wire harness assemblies.

SH, GH, and ZH appear in medical handheld devices, miniature instrumentation, board-to-board flex jumpers, and any application where 1 A is sufficient and PCB area is at a premium. GH is preferred over SH wherever vibration is a concern, because GH adds the positive latch SH lacks at only 0.25 mm of additional pitch.

JST Board-to-Wire Series Comparison

Specification FAQ

Is JST PH or XH better for general-purpose industrial wiring?

For industrial board-to-wire under 3 A, JST XH is the better default. Its 3 A per circuit at 250 V AC/DC clears most peripheral and accessory loads on a PLC or controller, and the 2.5 mm pitch accepts AWG 22–30, giving more wire-sizing flexibility than PH's 2.0 mm pitch. Specify PH only when XH's footprint is too large for the available PCB area or when 2 A and 100 V coverage is sufficient.

When does miniaturizing to JST SH or GH make engineering sense?

SH or GH is justified when a 10-circuit XH header — roughly 25 mm of PCB edge — won't fit the available board space. A 10-circuit GH header reduces that to 12.5 mm; SH cuts it to 10 mm. The tradeoff is reduced current capacity (1 A per circuit), narrower AWG range, and higher assembly cost from precision crimp tooling.

Can aftermarket "JST-compatible" terminals replace original JST terminals?

Aftermarket terminals from non-JST sources frequently miss JST's published crimp-height tolerance, fail pull-force minimums in IPC-620 Section 19, or use plating thickness below the original specification. For IPC/WHMA-A-620 Class 2 or Class 3 builds, original JST or licensed-equivalent terminals with documented lot traceability are required. Hobbyist-grade equivalents are not acceptable for industrial or regulated applications.

What pull-force values are required for IPC-620 Class 2 acceptance on JST crimps?

IPC/WHMA-A-620 Section 19 specifies minimum pull-force by AWG, not by connector series. For AWG 22 the minimum is 8 lbf (35.6 N); for AWG 26 it is 3 lbf (13.3 N); for AWG 30 it is 1.5 lbf (6.7 N). These minimums apply equally to PH, XH, SH, ZH, and GH crimps. Class 3 acceptance adds micro-section inspection per IPC-A-610.

What lead time and MOQ apply to custom JST cable harness assemblies?

Prototype quantities (under 100 units) for custom JST harnesses across PH, XH, SH, ZH, and GH typically deliver in 2–3 weeks with first-article documentation including crimp pull-test results. Production volumes (1,000+) move to dedicated tooling and run 4–6 weeks. MOQ varies by connector pitch and AWG — smaller series (SH/GH) generally require higher MOQ due to crimp tooling setup time. Provide the JST part number, circuit count, and wire AWG to scope a specific quote.

Selecting between JST PH, XH, SH, ZH, and GH starts with pitch and current and ends with whether the application can tolerate friction-fit retention. For most industrial board-to-wire applications under 3 A, XH is the engineering default; for compact assemblies subject to vibration, GH or ZH preserves the positive latch at reduced pitch; SH belongs to applications where 1.00 mm pitch is the absolute constraint and retention is solved at the enclosure level. Validate every crimp against JST's published crimp-height specification and the IPC/WHMA-A-620 acceptance class required for the end application.