Why Molex Wire-to-Board Families Matter
Molex built its reputation on wire-to-board connectors, and its 1.00 mm to 3.96 mm families remain workhorses in consumer electronics, appliances, industrial controls, and automotive modules. Picking the wrong series costs time in rework and money in returns, so it pays to understand what separates PicoBlade, Pico-Clasp, SL, and KK.
PicoBlade (1.25 mm Pitch)
PicoBlade is a 1.25 mm pitch, single-row wire-to-board system rated at 1 A per circuit. Its friction lock holds the mated pair reliably without a latch, and the compact size suits space-constrained boards such as wearables, cameras, and small motors. Choose PicoBlade when you need density and low current – signal and low-power connections where a millimeter of board space matters.
Pico-Clasp (1.00 mm Pitch)
Pico-Clasp pushes pitch down to 1.00 mm, with a positive latch that gives an audible and tactile click when fully mated. That latch makes it a favorite where vibration or handling could otherwise loosen a friction-lock connector. It is rated at 1 A per circuit and is common in portable devices, drones, and battery-powered products. The trade-off for the finer pitch is stricter wire management and tighter PCB design rules.
SL (2.54 mm Pitch)
SL is a 2.54 mm pitch family that feels almost industrial next to the pico range: higher current, robust latching, and excellent retention. It is widely used in appliances, HVAC controls, and industrial equipment where connectors are handled during assembly and service. If you need a familiar 0.1-inch-style pitch with real mechanical grip, SL is usually the answer. The broader connector-selection logic is covered in our PCB connector selection guide.
KK (2.54 mm and 3.96 mm)
KK is the classic Molex interconnection system, long synonymous with wire-to-board in appliances and white goods. Headers, receptacles, and crimp terminals are available in 2.54 mm and 3.96 mm variants, with current ratings climbing as pitch grows. KK is mature, cheap, and everywhere, which makes it easy to source but also easy for counterfeiters to clone – so traceability matters. Molex’s own higher-current Micro-Fit and Mini-Fit ranges are compared in our Micro-Fit vs Mini-Fit Jr article.
Comparing the Families
Density vs robustness
Pico-Clasp (1.00 mm) and PicoBlade (1.25 mm) win on density; SL and KK win on robustness and current. As a rule, the smaller the pitch, the more the design depends on good strain relief, because a fine-pitch contact cannot tolerate much pull force.
Current rating
Fine-pitch families sit around 1 A per circuit; KK and SL climb meaningfully higher as pitch increases. Always derate for the number of energized circuits and ambient temperature.
Locking and retention
PicoBlade uses a friction lock; Pico-Clasp, SL, and most KK variants offer positive latches. Match the retention to the environment – a static connector inside an enclosure behaves very differently from one on a moving cable.
Termination and Wire Gauge
All four families are crimp-terminated, which means the crimp tool and the terminal-to-wire match determine field reliability as much as the connector itself. Use the Molex-specified tooling, verify pull force, and inspect for insulation in the crimp barrel and for strands missing the wire crimp. Our crimp termination quality guide walks through the defects to screen.
Sourcing Molex Connectors Reliably
Molex parts are heavily counterfeited, so buy from authorized channels or suppliers who document traceability. Confirm the housing, terminal, and header part numbers separately – mismatched terminal-and-housing combinations are a frequent and avoidable assembly problem.
By Technology supplies Molex PicoBlade, Pico-Clasp, SL, KK, and related series with traceable sourcing and cross-references to alternates. Send your connector list to sales@by-techs.com and we will confirm availability, pricing, and lead time.