---
type: category
name: "Joining"
processes: 18
url: https://manufacturingprocesses.org/processes/joining
---

# Joining

18 manufacturing processes in the joining family.

Joining processes combine two or more parts into an assembly, either
permanently (welding, brazing, adhesive bonding) or reversibly
(fasteners, snap fits).

The design question is rarely which joining process is strongest, but
which one tolerates the materials, thicknesses and access you already
committed to upstream.

## Processes

| Process | Tolerances | Typical volumes | Lead time |
| --- | --- | --- | --- |
| [Adhesive Bonding](https://manufacturingprocesses.org/processes/joining/adhesive-bonding.md) | Bond line 0.005–0.010 in (0.13–0.25 mm) held with glass beads or shims; assembly position set by the bond fixture, commonly ±0.010 in (±0.25 mm) | 1 to 1,000,000+ | Seconds to fixture with cyanoacrylate; 4–24 h to handling strength and about 7 days to full cure at room temperature; 30–60 min at 250–350 °F (120–175 °C) for heat-cured structural epoxy |
| [Arc Welding](https://manufacturingprocesses.org/processes/joining/arc-welding.md) | ±1/16 in (±1.6 mm) on welded assembly dimensions; ±1/32 in (±0.8 mm) with hard fixturing; tighter only by machining after welding | 1 to 1,000,000+ per year — manual for one-offs and short runs, robotic cells for repeat production | Same day to 1 week for manual one-off weldments; 4–8 weeks to bring a robotic cell online including fixture build and WPS/PQR qualification |
| [Friction Welding](https://manufacturingprocesses.org/processes/joining/friction-welding.md) | Rotary: finished length controlled to about ±0.010 in (±0.25 mm) through upset control; FSW: butt gap under 10% of thickness, plate flatness governed by clamping | 500 to 1,000,000+ per year for rotary; FSW is economic from low hundreds of panels upward | 1–30 s cycle for rotary friction welds; 4–12 weeks for machine tooling, clamping fixtures and parameter development |
| [Hot Plate Welding](https://manufacturingprocesses.org/processes/joining/hot-plate-welding.md) | Assembly height after welding ±0.010–0.020 in (±0.25–0.5 mm), controlled by a positive stop rather than by molded part height; meltdown 0.04–0.16 in (1–4 mm) | 100 to 1,000,000+ per year; field pipe fusion is one joint at a time | 15–120 s per cycle; 3–8 weeks for platen and nest tooling |
| [Joinery](https://manufacturingprocesses.org/processes/joining/joinery.md) | Glue line of 0.002–0.006 in (0.05–0.15 mm) for PVA; joints fitted to firm hand pressure rather than to a numeric tolerance | 1 to a few thousand — hand work for one-offs, jigged or CNC-cut joinery for batch production | Minutes to an hour per joint depending on method; 30–60 minutes clamp time and 24 hours to full adhesive cure |
| [Laser Plastic Welding](https://manufacturingprocesses.org/processes/joining/laser-plastic-welding.md) | Clamped joint gap ≤ 0.004 in (0.1 mm) required across the seam; quasi-simultaneous collapse controlled to about ±0.001 in (±0.025 mm) | 1,000 to 5,000,000+ per year; contour welding is viable from prototype quantities | Seconds to a few tens of seconds per part for contour welding, under 5 s for simultaneous; 4–10 weeks for transparent clamping tooling and part-specific optics |
| [Mechanical Fastening](https://manufacturingprocesses.org/processes/joining/mechanical-fastening.md) | Normal-fit clearance holes about 1/32 in (0.8 mm) over nominal per ASME B18.2.8 for screws up to 1/2 in; preload scatter ±25–35% with torque control, ±15% with angle control, ±5–10% with bolt elongation measurement | 1 to 10,000,000+ | Off-the-shelf hardware in hours to days; seconds per fastener at assembly |
| [PCB Assembly (SMT Reflow)](https://manufacturingprocesses.org/processes/joining/pcb-assembly-smt-reflow.md) | Placement accuracy ±0.001–0.002 in (±25–50 µm) at 3σ; stencil foil 0.004–0.006 in (100–150 µm) with aperture area ratio above 0.66; board bow and twist ≤ 0.75% per IPC-6012 | 5 to 1,000,000+ boards | 1–3 minutes of process time per board once running; 1–3 weeks for a prototype build including stencil, programming and component procurement |
| [Power Beam Welding](https://manufacturingprocesses.org/processes/joining/power-beam-welding.md) | Beam-to-seam alignment ±0.004 in (±0.1 mm); joint gap ≤ 0.004 in (0.1 mm) for autogenous welds; post-weld distortion roughly an order of magnitude below an equivalent arc weld | 100 to 1,000,000+ per year | Seconds of weld time per joint; 2–8 weeks for precision fixtures and schedule development; EBW adds minutes of chamber pump-down per load |
| [Resistance Welding](https://manufacturingprocesses.org/processes/joining/resistance-welding.md) | ±1/32 in (±0.8 mm) on fixtured sheet assemblies; nugget diameter held to 4√t–5√t (t in mm); electrode indentation ≤ 20–25% of sheet thickness | 5,000 to 10,000,000+ per year — the capital only pays back at production volume | 0.1–0.5 s of weld time and 1–2 s per spot on a robotic gun; 2–8 weeks for weld fixtures, guns and electrode tooling |
| [Riveting](https://manufacturingprocesses.org/processes/joining/riveting.md) | Hole 0.003–0.006 in (0.08–0.15 mm) over nominal shank; driven head 1.5x shank diameter wide by 0.5x shank diameter high; SPR interlock commonly ≥ 0.016 in (0.4 mm) with ≥ 0.008 in (0.2 mm) remaining bottom sheet | 1 to 10,000,000+ | Immediate with off-the-shelf hardware; 1–2 s per joint for automated self-piercing riveting; 4–10 weeks for SPR dies and C-frame tooling |
| [Soldering and Brazing](https://manufacturingprocesses.org/processes/joining/soldering-and-brazing.md) | Joint clearance 0.001–0.005 in (0.025–0.13 mm) for brazing, 0.003–0.005 in (0.075–0.13 mm) for soldering, specified at brazing temperature; assembly position set by fixture or self-locating features | 1 to 1,000,000+ — torch for one-offs and repair, continuous or vacuum furnace at production volume | Seconds to minutes for torch and induction work; 20–90 minute furnace cycles including ramp and controlled cool |
| [Staking](https://manufacturingprocesses.org/processes/joining/staking.md) | Formed head height controlled to about ±0.005 in (±0.13 mm) by tool stop; hole-to-boss clearance 0.002–0.010 in (0.05–0.25 mm) | 1,000 to 10,000,000+ per year | 0.2–0.8 s per ultrasonic stake, 4–15 s per hot air cycle; 2–5 weeks for multi-tip forming tooling |
| [Timber Frame Structures](https://manufacturingprocesses.org/processes/joining/timber-frame-structures.md) | CNC-cut joinery to about ±1/16 in (±1.5 mm) over member lengths of 40 ft (12 m) and more; erection tolerances are set by the project specification | — | Months from design freeze to erection, dominated by engineering, shop drawing approval and engineered-timber mill scheduling; CNC cutting of a frame itself takes days |
| [Ultrasonic Welding](https://manufacturingprocesses.org/processes/joining/ultrasonic-welding.md) | Weld collapse held to ±0.002 in (±0.05 mm) with distance-mode control; joint faces should be molded flat and parallel to the limit the tool allows | 10,000 to 10,000,000+ per year | 0.1–1.0 s weld, under 2 s total cycle; 2–4 weeks for horn and nest fixture tooling |
| [Upholstery](https://manufacturingprocesses.org/processes/joining/upholstery.md) | — | 1 to 100,000+ — hand work for one-offs and restoration, CNC cutting and sewing cells for production runs | Hours of hand labor per seat for traditional sprung upholstery; production cut-and-sew cells work in minutes per panel once patterns and cutting nests exist |
| [Vibration Welding](https://manufacturingprocesses.org/processes/joining/vibration-welding.md) | Meltdown controlled to about ±0.004 in (±0.1 mm); final assembly height set by a positive stop or machine collapse control rather than by molded part height | 5,000 to 5,000,000+ per year | 6–20 s cycle including 1–10 s of vibration and a 2–6 s hold; 3–8 weeks for matched nest tooling |
| [Weaving](https://manufacturingprocesses.org/processes/joining/weaving.md) | — | 1 to a few thousand — hand weaving for one-offs and restoration, pre-woven webbing for production | Hours per seat for hand weaving; pre-woven webbing is routed, splined and trimmed in well under an hour |

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*Source: [Manufacturing Processes](https://manufacturingprocesses.org/processes/joining)*