AN Solid Rivet Reference
AN426 & AN470 — Dimensions, Drill Sizes, Shop Head & Installation
Part Number Decoder
AN470AD4-5 = Universal head, 2117-T4 aluminum, 1/8" dia, 5/16" total length
Style
Dia Code
Length Dash
Material Codes & Head Markings
| Part # | Shank Ø | Fraction | Drill | Hole Dia | Head Ø | C/S Depth | Min Shop Ø | Min Shop Ht | Typical Use |
|---|---|---|---|---|---|---|---|---|---|
| AN426AD3 | 0.094" | 3/32" | #41 | 0.096" | 0.270" | 0.083" | 0.141" | 0.047" | Control surface skins, fairings, light skins — dimple required for most EAB skins |
| AN426AD4 | 0.125" | 1/8" | #30 | 0.128" | 0.360" | 0.110" | 0.188" | 0.063" | Primary skins to ribs — most common flush rivet in EAB construction |
| AN426AD5 | 0.156" | 5/32" | #21 | 0.159" | 0.450" | 0.138" | 0.234" | 0.078" | Spar flanges, heavier skins, high-load skin joints |
| AN426AD6 | 0.188" | 3/16" | #11 | 0.191" | 0.540" | 0.165" | 0.281" | 0.094" | Heavy skins, primary structural flush joints |
| AN426AD8 | 0.250" | 1/4" | F | 0.257" | 0.720" | 0.220" | 0.375" | 0.125" | Heavy plate — rarely used in EAB construction |
Length Selection
| Rivet | Add for Tail (1.5D) |
|---|---|
| AD3 (3/32") | + 0.141" |
| AD4 (1/8") | + 0.188" |
| AD5 (5/32") | + 0.234" |
| AD6 (3/16") | + 0.281" |
| AD8 (1/4") | + 0.375" |
Grip = total material stack thickness
Dash # = total length in 1/16ths
Always round UP to next standard size
Countersink vs. Dimple (AC 43.13-1B)
| Rivet | C/S Depth | Min Sheet for MCS |
|---|---|---|
| AD3 | 0.083" | 0.125" |
| AD4 | 0.110" | 0.165" |
| AD5 | 0.138" | 0.207" |
| AD6 | 0.165" | 0.248" |
| AD8 | 0.220" | 0.330" |
AN426 Installation Notes
Material Selection AN426AD is standard for all flush applications in EAB. Use AD (2117-T4) — no re-treatment required. Do not substitute D or DD without a controlled re-heat-treat plan (AC 43.13-1B 4-45).
Countersink Quality Use a cage countersink tool for consistent depth. Deburr the hole before countersinking. Verify fit with a rivet placed dry in the countersink — flush within 0.003" before driving. Avoid a knife edge in the skin.
Rivet Removal Center-punch, drill with a bit 1/16" smaller than the shank diameter, then drive the manufactured head sideways with a punch. Do not enlarge the hole. If the hole is damaged, use the next size up per plans, or consult AC 43.13-1B Chapter 2 for repair.
| Part # | Shank Ø | Fraction | Drill | Hole Dia | Head Ø | Head Ht | Min Shop Ø | Min Shop Ht | Typical Use |
|---|---|---|---|---|---|---|---|---|---|
| AN470AD3 | 0.094" | 3/32" | #41 | 0.096" | 0.188" | 0.071" | 0.141" | 0.047" | Light ribs, control surface substructure, light brackets |
| AN470AD4 | 0.125" | 1/8" | #30 | 0.128" | 0.250" | 0.095" | 0.188" | 0.063" | Most common — ribs to spars, skin to substructure, brackets |
| AN470AD5 | 0.156" | 5/32" | #21 | 0.159" | 0.313" | 0.119" | 0.234" | 0.078" | Spar webs, heavy brackets, high-load structural joints |
| AN470AD6 | 0.188" | 3/16" | #11 | 0.191" | 0.375" | 0.143" | 0.281" | 0.094" | Primary structural joints, wing root, spar carry-through |
| AN470AD8 | 0.250" | 1/4" | F | 0.257" | 0.500" | 0.190" | 0.375" | 0.125" | Heavy primary structure — rarely used in EAB |
Shop Head Requirements
| Rivet | Min Shop Ø | Min Shop Ht |
|---|---|---|
| AD3 (3/32") | 0.141" | 0.047" |
| AD4 (1/8") | 0.188" | 0.063" |
| AD5 (5/32") | 0.234" | 0.078" |
| AD6 (3/16") | 0.281" | 0.094" |
| AD8 (1/4") | 0.375" | 0.125" |
Shop Ht = 0.5 × shank dia
Use a rivet gauge to verify height
Applies to AN426 shop heads as well
Common AD4 Length Examples
| Material Stack | Grip | Select |
|---|---|---|
| 0.025" + 0.025" | 0.050" | AD4‑4 (1/4") |
| 0.032" + 0.032" | 0.064" | AD4‑5 (5/16") |
| 0.032" + 0.040" | 0.072" | AD4‑5 (5/16") |
| 0.040" + 0.040" | 0.080" | AD4‑5 (5/16") |
| 0.040" + 0.063" | 0.103" | AD4‑5 (5/16") |
| 0.063" + 0.063" | 0.126" | AD4‑6 (3/8") |
Protrusion before driving = 1.5 × 0.125" = 0.188"
Round up to next 1/16" increment
AN470 Installation Notes
Head Seating Manufactured head must be fully flat against the material. A tilted or rocked head is rejectable. Verify the head does not rotate after driving — rotation indicates the shank did not properly fill the hole.
Hole Fit The driven shank must fill the hole. Standard clearance is 0.002"–0.003" (#41 for AD3, #30 for AD4). Hole max oversize: +0.003". If the hole is oversize, move up one shank size or follow AC 43.13-1B Chapter 2 repair procedures.
Rejection Criteria Reject if: cracked shop head, shop head off-center by >10% of head dia, tipped or shaved head, shop head smaller than minimum dimensions, manufactured head lifted off surface, or rivet installed in wrong material.
| Rivet | Dia (D) | Min Edge Distance (2D) | Typical Edge (2.5D) | Min Pitch (3D) | Typical Pitch (4D) | Min Row Spacing (2.5D) |
|---|---|---|---|---|---|---|
| AD3 | 3/32" (0.094") | 0.188" | 0.234" | 0.281" | 0.375" | 0.234" |
| AD4 | 1/8" (0.125") | 0.250" | 0.313" | 0.375" | 0.500" | 0.313" |
| AD5 | 5/32" (0.156") | 0.313" | 0.391" | 0.469" | 0.625" | 0.391" |
| AD6 | 3/16" (0.188") | 0.375" | 0.469" | 0.563" | 0.750" | 0.469" |
| AD8 | 1/4" (0.250") | 0.500" | 0.625" | 0.750" | 1.000" | 0.625" |
Edge Distance Minimum 2D from rivet centerline to nearest material edge. Below 2D risks tear-out under load — reject. Typical 2.5D per Van’s Aircraft plans. Always measure to the closest free edge.
Pitch & Spacing Minimum 3D center-to-center. Closer spacing reduces net section; wider reduces load transfer. Typical 4D–8D. Do not deviate from plans without engineering analysis.
Hole Preparation Match-drill through both parts clamped together. Deburr both faces. Hole must be clean, round, and perpendicular. Max oversize +0.003". If enlarged beyond tolerance, move up one rivet size or follow AC 43.13-1B Chapter 2.
Inspection (AC 43.13-1B 4-58) Manufactured head: flush/fully seated, no cracks, not rotatable. Shop head: concentric, no cracks, meets minimum diameter and height. No visible gap between manufactured head and material surface.