3.50 mm 2-Pin Screw Terminal Footprint and DFM Practical Guide

3.50 mm 2-position screw terminal is a through hole package used for through hole assembly, also seen labeled 3.5 mm terminal block, 2-way Euroblock, two-pole wire terminal. A dependable footprint follows the exact orderable-device drawing rather than the family name: nominal body Often about 7 × 7–9 mm; series-specific, overall span Includes wire funnel and screw overhang, seated height Commonly 8–12 mm, pitch 3.50 mm, pin count 2, and exposed pad Plated through-hole annuli.

Use the selected terminal's rectangular or round lead drawing, recommended finished hole, and housing outline.

Typical uses include low-voltage power, sensors, relay contacts. 3.50 mm pitch does not make terminal-block series interchangeable; lead shape, body depth, rating, and tooling vary.

• A 3.50 mm pitch is compact for field wiring, but different series move the lead relative to the wire entry and use materially different body depths.
• The finished hole must fit the lead at maximum material condition plus insertion tolerance and plating; the drill file normally specifies the pre-plating tool size.

Point wire entry toward an accessible board edge, reserve screwdriver and ferrule space, and size copper from current and temperature rise rather than connector pitch.

• Reserve the full connector or component envelope on both sides, include mating and wire-entry space, and keep copper clear of hardware and hand-tool access.

Hand assembly is rated easy. Hand, wave, or selective solder with the block fully seated. Watch for wrong wire-entry direction, small holes, and inadequate mechanical support.

• Use strong annular rings, adequate edge setback, and selective-solder clearance; heavy wire torque should transfer into the board and enclosure safely.
• Choose annular rings from the fabricator's registration allowance and confirm whether slots, press-fit holes, or non-plated features need separate drill outputs.
• Account for wave or selective solder orientation, pallet access, thermal spokes, and bottom-side protrusion before panel release.

Inspection focus:

• Inspect seating and barrel fill, torque wires with the specified tool, then pull and load-test the connection while monitoring temperature.
• Inspect barrel fill, wetting around the lead, polarity, seating, and mechanical alignment; continuity alone does not prove a durable connector joint.

Common mistakes:

• Mirroring the footprint can turn the wire funnel inward so the terminal fits electrically but cannot be wired inside the enclosure.
• Do not use nominal lead width as the finished-hole size or forget that plating reduces the hole after drilling.

1. Before approving 3.50 mm 2-position screw terminal, compare the exact orderable-device drawing with the library item: body range (Often about 7 × 7–9 mm; series-specific), terminal or lead span (Includes wire funnel and screw overhang), pitch (3.50 mm), pin count (2), height (Commonly 8–12 mm), and exposed-pad definition (Plated through-hole annuli). Record the source drawing revision and every intentional courtyard, toe, heel, side, mask, or paste adjustment.
2. Treat the easy hand-solder rating as a prototype-planning input, not proof of production yield. Review wrong wire-entry direction, small holes, and inadequate mechanical support with the assembler, confirm that hand, wave, or selective solder with the block fully seated is compatible with the build, and require the S1 connectivity gate plus relevant S2 geometry checks to pass against the released footprint and selected fabrication profile.

Manufacturing gate checks:

1. S1Pad count, numbering, and schematic parity. Lead shape, finished holes, pitch, wire-entry courtyard, edge clearance, current copper, and net polarity must all match.
2. S2Finished-hole tolerance and annular ring. The lead must insert after plating while retaining enough copper for registration, solder fill, and mechanical load.
3. S2Finished-hole size and annular ring. Drill, plating, lead tolerance, and the remaining annular ring must agree with the fab capability.