IP68 Outdoor Waterproof Connectors M21 Straight Assembled Plug Soldering Wire Connector

The M21 Assembly Plug (also known as M21 field-wireable plug, 21 mm threaded circular connector, SP21-class assemblable plug) is a 21 mm-class threaded circular interconnect designed for ≈21 mm panel cut-outs with M21-class coupling nuts. As the larger sibling of the SP17 and positioned just below M25 in current capability, it offers robust performance: 2-pin configurations handle 25-30 A at 300-500 V AC/DC, 3/4-pin versions manage 12-15 A, 5-pin handles 5 A, and up to 12-pin signal versions support 5 A. Standard IP67 protection is available with optional IP68 rating when mated.

The "Assembly" designation means the plug body ships disassembled, allowing users to bring their own cable, strip and solder/screw conductors into the contact carrier, clamp the rear gland, and lock the coupling nut. It follows the same 21 mm form factor as the widely used SP21/MP-T21 family, ensuring compatibility with standard 21 mm panel sockets.

• Coupling: M21-class ≈21 mm nut OD, threaded fine-pitch lock
• Form Factors: Cable plug (inline), 90° elbow plug, panel flange socket, rear-nut socket
• Termination Options: Solder cup (standard), screw-clamp (2-4 pin), IDC optional
• Cable Gland: Type I 4.5-7 mm, Type II 7-12 mm with rear rubber gland + compression nut
• Contact Material: Brass with gold flash (3 µ"+ minimum) or tin plating
• Insert Material: PPS for high temperature resistance (260 °C peak)
• Shell Options: PA66+GF (black/blue/yellow), PC option; Ni-plated brass optional
• Sealing System: Silicone O-ring face seal + rear grommet + optional mating cap

• vs M20 Quick-lock: +5-10 A headroom on 2-pin, field termination options, superior vibration resistance
• vs M25 Assembly Plug: 30% smaller footprint, lower BOM cost, sufficient for ≤30 A applications
• vs SP13/SP17: Triple the 2-pin current capacity (30 A vs 13 A), ideal for mid-large LED/power applications
• vs Metal Aviation Connectors: IP68 sealed construction, rust-free, 50-70% cost savings
• vs Junction Box + PG Gland: Single reusable sealed plug solution with keyed polarization

• Outdoor LED & Street Lighting: Streetlight power trunk, facade/landscape LED splits, LED billboard power+dimming, tunnel lamp mid-span repair
• Solar & Storage Systems: Solar streetlight battery-to-lamp connections, PV combiner auxiliary power, off-grid cabinet 48 V bus taps
• Industrial Power: 230 VAC cabinet auxiliary feeds, 24 VDC valve island trunks, small motor/gearbox power connections, AGV 48 V charge drops
• Robotics & AGV: Mobile robot power+communications, cobot wrist tool feeds, drag-chain end power with PUR cable
• Marine / RV / Agriculture: Deck lighting trunks, tractor implement 12/24 V connections, irrigation valve manifold power, yacht battery disconnects
• Stage & Event: Outdoor LED decor trees, temporary performance light power joins, portable generator auxiliary outlets