S-320AT Inline Auto Lead Cutter: Repeatable Lead Trim After Wave Soldering

Boards come off the wave solder with leads standing four or five millimetres proud. An operator works down each board with side cutters — sixty joints, sixty cuts, and clippings that land wherever they land. Residual length varies with wrist angle, so the next station sees anything from flush to three millimetres on one part number. The S-320AT turns trimming into a conveyor step: a programmed path cuts every lead to the length you set, and a vacuum collects the offcuts.

The cost you haven't named

• Cut length is set by a wrist, not by a programme. Hand clipping produces a distribution rather than a dimension. When a housing, heatsink or ICT fixture needs clearance, that spread is where interference comes from.
• Clippings go everywhere. Trimmed pins land on the bench, in the conveyor, on the floor and occasionally on the board. Loose metal on a populated assembly is a short-circuit risk that inspection finds late, if at all.
• Throughput is capped by the slowest pair of hands. A THT line running at wave-solder pace queues behind a bench operation that adds no product value.
• Rework is charged to the wrong station. A lead bent or pulled during manual trimming shows up as a solder joint defect at test, so the loss is booked against the soldering profile instead of against handling.
• Ergonomics carry a hidden bill. Repetitive clipping drives wrist strain and turnover, and that cost lands in hiring and training rather than in the bill of materials.
• Offline cutters add a handling step. Bench-top machines — including the SM-306 loose capacitor lead cutter in our range — suit loose parts and pre-form work. A board that has already been soldered should not go back to a bench.

The Four-Point Inline Lead Trim Audit

Specify the trim before you specify the machine, and the quotation becomes a short conversation.

1. Measure the lead population. Count cutting points per board, record lead diameter (up to 1.6 mm) and lead length before cut (under 6 mm), and check the tallest body on the panel against the 110 mm clearance. Anything outside those windows needs a different cutter head, and it is cheaper to find that on paper than after installation.

2. Set the residual length window. Decide what the drawing requires — 0.5 to 5 mm adjustable on this machine — and confirm the tolerance your next assembly step can absorb, which the machine holds at ±0.1 mm.

3. Size the cut rate to the line. Multiply cutting points per board by boards per hour and compare with the rating of over 7,200 points per hour. If the number is close, ask about the conveyor handshake before you ask about the cutter.

4. Plan the workholding and the handshake. Confirm the panel size (X=250 mm, Y=320 mm), the 0.8–2.5 mm thickness range, and whether each panel has a process edge. The minimum is D=3 mm; without it, a fixture is required. SMEMA signalling then decides whether the machine runs unattended between wave solder and the next station.

The vehicle: S-320AT Inline Auto Lead Cutter

The S-320AT is built for one position in the line: directly after wave soldering, in the conveyor. That is the difference between this machine and a bench-top cutter. The SM-306 and similar offline units handle loose components, cutting capacitor and resistor leads before insertion or trimming parts in bulk. The S-320AT receives a soldered PCBA, holds it on a fixture, and cuts leads one by one along a programmed path, so the board never leaves the line and the residual length is a programmed value rather than a habit.

• Measure the lead population → defined cutting envelope. Leads up to 1.6 mm diameter and under 6 mm before cut, bodies under 110 mm tall, on boards up to X=250 × Y=320 mm and 0.8–2.5 mm thick. Parts outside that envelope are identified during the audit and quoted with a matched cutter head.
• Set the residual length window → 0.5–5 mm adjustable at ±0.1 mm. Cut length is entered as a value, so every board in the run leaves with the same residual — the setting that matters when a housing or test fixture has a clearance limit.
• Size the cut rate → over 7,200 points per hour on a programmed path. The head follows the board's own programme, cutting point by point, which keeps pace with wave-solder output instead of queueing it into racks for a bench operation.
• Plan the workholding and handshake → SMEMA conveyor with vacuum waste recovery. The inline conveyor takes boards from the wave solder automatically, and the vacuum picks up trimmed pins as they are cut, so offcuts are collected and recycled rather than scattered across the line.

Specification note: cut length range, achievable points per hour on your panel, cutter head design, fixture requirement, conveyor height and power supply should be confirmed at quotation, because they depend on your PCB dimensions, component mix and line layout.

Specifications

| Parameter | Value |

| --- | --- |

| PCBA max size | X = 250 mm, Y = 320 mm |

| PCB thickness | 0.8–2.5 mm |

| Lead length before cut | < 6 mm |

| Lead cut length range | 0.5–5 mm, adjustable |

| Cutting precision | ±0.1 mm |

| Component body height | < 110 mm |

| Component lead diameter | < 1.6 mm |

| Cutting efficiency | > 7,200 points/hr |

| Cutter material | Tungsten steel |

| Power | 700 W |

| Minimum process edge | D = 3 mm (fixture required without process edge) |

| Integration | SMEMA-compatible inline conveyor |

| Waste handling | Automatic vacuum collection and pin recycling |

The loop: re-audit trim quality every week

Cutter edges wear, panel programmes change and fixturing loosens — all three show up in the cut length before they show up as a fault. Build a loop: every week, sample trimmed boards from each active programme, measure residual length on the tallest and shortest leads, and compare against the commissioning value. Set blade replacement intervals from your own cut-point counts. When a new panel enters the run, repeat the audit before volume builds — body-height and process-edge checks are the two items most often found late.

Your next step

Send us your board dimensions, a component list with lead diameters and body heights, your target residual length and boards per hour. We will return a trim review showing where the S-320AT sits in your line, whether a fixture or custom cutter head is needed, and what to confirm at quotation. Reach Jason at jasonwu@smthelp.com or on WhatsApp +86 13602562576.

FAQ

What board sizes does the S-320AT handle?

Panels up to X=250 mm by Y=320 mm, thickness 0.8–2.5 mm. The minimum process edge is D=3 mm; a fixture is required if the panel has no process edge.

What lead sizes can it cut?

Lead diameters up to 1.6 mm and length under 6 mm before cutting, with the residual length adjustable between 0.5 and 5 mm at ±0.1 mm precision.

How does it handle the offcuts?

Trimmed pins are vacuumed as they are cut and recycled, so clippings do not reach the board, the conveyor or the floor.

Can it be added to an existing line?

Yes. The inline conveyor is SMEMA-compatible, taking boards from the wave soldering machine and passing them downstream, and cutter heads can be designed for different product types.

Jason Wu

Founder & CEO, Southern Machinery (Shenzhen Southern Machinery Sales And Service Co., Ltd.)

Email: jasonwu@smthelp.com / info@smthelp.com

WhatsApp: +86 13602562576

Catalog & manuals: file.autoinsertion.com | Machine photos: ph.smthelp.com

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