Riveting
Riveting sets a rivet through aligned holes and upsets its tail so the joint clamps permanently, with no heat and no access to both sides for blind types.
- Part
- Joining
- Revised
- 2026-08-11
At a glance
- Family
- Mechanical
- Typical tolerances
- 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
- Typical volumes
- 1 to 10,000,000+
- Lead time
- 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
- Materials
- Metal, Plastic, Composite
What it is
Riveting sets a rivet through aligned holes and upsets its tail into a second head, clamping the joint permanently. There is no heat, so nothing is annealed, nothing distorts, and heat-treated alloys keep their temper — which is precisely why 2024 and 7075 aluminum aircraft structure is riveted rather than welded.
The joint is a shear joint. A driven solid rivet's allowable comes from the shear area of its shank at the rivet material's shear strength — 30 ksi (207 MPa) for the 2117-T4 alloy used in standard aircraft rivets — and the joint can equally fail by sheet bearing or edge tear-out, which is what edge distance and pitch rules exist to prevent.
The family covers solid rivets, blind rivets that need access to one side only, structural blind rivets, self-piercing rivets that make their own hole, and rivet nuts that leave a thread behind. Volumes run from a single repair to millions of joints a year on an automotive line.
How it works
- Drill and deburr. The hole is drilled 0.003–0.006 in (0.08–0.15 mm) over the rivet's nominal shank — a 1/8 in rivet takes a #30 drill at 0.1285 in. Both sides are deburred, and in aerospace practice the hole may be reamed and cold-worked. Drill sizes are on the drill size chart.
- Insert. Rivet length equals grip length plus about 1.5x diameter for a solid rivet — enough material to form the driven head without so much that it buckles.
- Upset. A bucking bar backs the tail while a rivet gun or squeeze tool deforms it. The shank swells to fill the hole (an important part of the joint's shear performance) and the tail flows into a driven head.
- Verify. The driven head is gauged: 1.5x shank diameter across and 0.5x shank diameter high is the standard target.
The other rivet types
Blind rivets are set from one side. A mandrel is pulled through the rivet body, flaring the far end, and then snaps at a designed break point. Standard open-end pop rivets are for light-duty and non-structural work; structural blind rivets retain and lock the mandrel stem so it contributes shear area and the joint does not lose the pin in service.
Self-piercing rivets (SPR) need no hole at all. A punch drives a semi-tubular rivet through the top sheet and flares it into — but not through — the bottom sheet, which is held in a profiled die. Setting force is roughly 6,700–18,000 lbf (30–80 kN), the cycle is 1–2 s, and total stack thickness runs about 0.04–0.24 in (1–6 mm). SPR is how aluminum-intensive car bodies are assembled, because those alloys resist spot welding and cannot be arc welded without losing temper.
Rivet nuts (blind threaded inserts) are set like a blind rivet but leave a threaded barrel behind, providing a serviceable thread in thin sheet or tube with one-sided access.
Design guidelines
Edge distance and pitch are the strength rules
Edge distance from the rivet centerline to the sheet edge must be at least 2x the rivet diameter, and 2.5x is the working target — closer and the joint tears out through the edge instead of loading the rivet. Rivet pitch along a row is a minimum of 3x diameter and typically 4–6x; row spacing at least 2.5x diameter. These are the numbers that keep failure in the rivet, where it is predictable, rather than in the sheet.
Hole and grip
Drill the hole 0.003–0.006 in (0.08–0.15 mm) over the nominal shank so the rivet enters without force but swells to fill on upsetting. Rivet length for a solid rivet is grip plus 1.5x diameter. Blind rivets are sold in grip ranges — a rivet whose grip range does not match the actual stack will either not clamp or will not form a proper blind head, and this is the single most common riveting error.
Loading and access
Rivets carry shear well and tension poorly, and solid rivets in particular are not tension fasteners. Where a joint sees pull-through, use a structural blind rivet with a retained locking stem, a bolted joint, or a washer or backing plate to spread the bearing load; in composite structures, bearing failure usually governs before rivet shear does. On access: solid riveting needs both sides (gun on one face, bucking bar behind), blind riveting needs one, and self-piercing riveting needs a C-frame with the die behind the joint — the same throat-depth constraint that governs resistance welding.
Material combinations
| Pair | Notes |
|---|---|
| Aluminum sheet to aluminum sheet | The classic case; 2117-T4 rivets in 2024/7075 structure retain full temper |
| Steel to steel | Solid or blind steel rivets; galvanized sheet rivets without any of the welding problems |
| Aluminum to steel | SPR and blind rivets both work; use a compatible rivet material and seal against galvanic corrosion |
| Composite to metal | Bearing failure governs — spread load with a washer or bushing, and never overtorque |
| Plastic to metal | Blind rivets with large flanges or backup washers; avoid clamping brittle resin directly |
| Dissimilar metals generally | Choose the rivet to be cathodic to the sheet, and wet-install with sealant in corrosive service |
Sheet thickness and gauge conversions are on the sheet metal gauge chart.
Inspection
Driven heads are gauged for diameter and height with go/no-go gauges — 1.5x diameter across and 0.5x diameter high on solid rivets. Blind rivets are checked for a properly formed blind-side head and, on structural types, for a retained and locked mandrel. Self-piercing rivets are qualified by cross-section: the accept criteria are a measured mechanical interlock (commonly 0.016 in / 0.4 mm or greater) and a minimum remaining bottom-sheet thickness (commonly 0.008 in / 0.2 mm), with setting force and displacement monitored on every joint in production. Eddy current and ultrasonic inspection are used to find cracked holes in aerospace structure.
| Feature | Recommended | Limit | Why |
|---|---|---|---|
| Edge distance | 2.5x rivet diameter | 2x minimum | Prevents edge tear-out |
| Pitch along a row | 4–6x diameter | 3x minimum | Prevents sheet failure between rivets |
| Row spacing | 3x diameter | 2.5x minimum | Same reason, transverse |
| Hole diameter | Nominal + 0.004 in (0.1 mm) | +0.003 to +0.006 in (0.08–0.15 mm) | Rivet must enter freely and swell to fill |
| Solid rivet length | Grip + 1.5x diameter | — | Material to form the driven head |
| Driven head | 1.5x diameter wide, 0.5x diameter high | Gauge every joint | The only visible evidence the rivet was set correctly |
| Blind rivet grip range | Match the actual stack | Never exceed | Wrong grip gives no clamp or no blind head |
| Loading | Shear | Not primary tension | Solid rivets are not tension fasteners |
Cost drivers
Riveting cost is hardware plus holes plus labor. The rivets themselves are inexpensive; the drilling, deburring and — in aerospace — hole quality control that precede them are not, and hand riveting a large panel is a substantial labor operation. This is why automated drill-and-rivet cells exist for aircraft panels and why any design decision that reduces hole count pays twice.
Self-piercing riveting inverts the structure: no drilling at all, a 1–2 s automated cycle, but a C-frame robot cell and part-specific dies as capital. It only makes sense at production volume, and it is chosen because the materials cannot be welded rather than because it is cheap.
The comparison that matters is usually against welding. Riveting adds hardware and holes but adds no heat, so heat-treated and dissimilar-material assemblies stay strong and stay flat — with no distortion correction and no post-weld heat treatment downstream.
- Reduce hole count by increasing rivet size where edge distance and pitch rules allow; fewer, larger rivets beat many small ones on labor.
- Use blind rivets to delete backside access, which often removes an entire fixture or an assembly sequence constraint.
- Standardize on one or two rivet diameters and grip ranges to cut tool changes and part numbers.
- Consider riveting plus adhesive (rivet bonding). The adhesive carries fatigue load and seals the joint while the rivets fixture it during cure — a common aerospace and automotive combination.
- Design flanges reachable by a C-frame if self-piercing riveting is in the plan; throat depth constrains the geometry exactly as it does for spot welding.
Questions
5 questionsWhat edge distance do rivets need?
At least 2x the rivet diameter from the centerline to the sheet edge, with 2.5x as the working target. Closer than 2x and the joint fails by tearing out through the edge of the sheet rather than by shearing the rivet, which is both weaker and far less predictable. Pitch along a row should be at least 3x diameter and is typically 4–6x.
Why rivet instead of weld?
Because riveting adds no heat. Heat-treated aluminum alloys such as 2024 and 7075 lose their temper and hot-crack when fusion welded, dissimilar metals form brittle intermetallics, and any welded assembly distorts. A riveted joint keeps the parent material at full strength, stays flat, and needs no post-weld heat treatment or straightening.
What is a self-piercing rivet and when is it used?
A semi-tubular rivet driven straight through the top sheet and flared into — not through — the bottom sheet against a profiled die, with no pre-drilled hole. Setting force is roughly 6,700–18,000 lbf (30–80 kN) over a 1–2 s cycle for stacks of about 0.04–0.24 in (1–6 mm). It is the standard joining method for aluminum-intensive car bodies, which resist spot welding.
How is a driven rivet inspected?
By gauging the driven head: 1.5x the shank diameter across and 0.5x the shank diameter high is the standard target, checked with go/no-go gauges. Blind rivets are checked for a properly formed blind-side head and a retained locked mandrel on structural types. Self-piercing rivets are qualified by sectioning, measuring the mechanical interlock and the remaining bottom-sheet thickness.
Can rivets carry tension loads?
Poorly, and solid rivets are not designed for it at all — they are shear fasteners. Where a joint sees pull-through, use a structural blind rivet with a retained locking stem, switch to a bolted joint, or spread the bearing load with a washer or backing plate. In composite joints, bearing failure of the laminate usually governs before the rivet does.