The drawing
Where to buy
Step by step
| Step | Action | What to do |
|---|---|---|
| 1 | Read the drawing or SRM | The rivet called up there is the answer. Everything below is for checking what you find. |
| 2 | Look at the manufactured head | Dome: universal. Flush: 100° countersunk. The driven head carries no mark. |
| 3 | Read the mark | None A, dimple AD, raised teat D, two dashes DD, raised cross B. |
| 4 | Measure the shank | Diameter in thirty-seconds of an inch: 3 is 3/32, 4 is 1/8, 5 is 5/32. |
| 5 | Write the part number | Standard, head series, alloy letters, diameter, length. Half lengths exist: MS20470AD4-3.5. |
| 6 | Check it can go back | Never a type of lower strength unless compensated. See the alloy check. |
Tools you need
| Tool | What for | Buying guide | Catalog |
|---|---|---|---|
| Rivet gauge or scale | Measure diameter and heads | Starter kit | — |
| Rivets, universal head | MS20470 | Solid rivets | MS20470 |
| Rivets, countersunk | MS20426 | Solid rivets | MS20426 |
| Assortment | For a small shop | — | Assortment |
Head marks and alloys
| Letter | Alloy | Head mark | Note |
|---|---|---|---|
| A | 1100 | None | Soft, non-structural |
| AD | 2117-T | Dimple | Most used repair rivet: installed as received |
| D | 2017-T | Raised teat | Higher strength than AD |
| DD | 2024-T | Two dashes | Too hard as received: annealed and kept cold, the "ice box" rivet |
| B | 5056 | Raised cross |
AC 43.13-1B par. 4-57a(2); FAA-H-8083-31B p. 4-31. E rivets have replaced most DD and install as received. The full chart has every marking.
The two heads you will see most
Universal
- Series
- MS20470, supersedes AN470
- Use
- Where the head has no aerodynamic importance; also replaces round, flat and brazier heads
- Size
- Head 2D wide, about 0.425D high
Countersunk
- Series
- MS20426, supersedes AN426
- Use
- Where a smooth surface is required
- Size
- 100° is the US standard angle
What to check when it is done
| Look at | Good | If not |
|---|---|---|
| Mark | Same as the rivets next to it, or as the drawing | Stop: find out which alloy belongs there |
| Head | Same type as the original | Do not swap flush for protruding on an aerodynamic surface |
| Size | Diameter matches the sheet and the pattern | Too big in thin sheet bulges round the head |
Questions people actually ask
What does AD mean on a rivet?
2117-T aluminium alloy, the dimple-marked rivet used for most repairs.
What do the numbers mean?
First the diameter in thirty-seconds of an inch, then the length in sixteenths: AD4-6 is 4/32 by 6/16, or 1/8 by 3/8 in.
Limits of this guide
What the sources support, and no further.
- The manual governs. Where the SRM, the drawing or the fastener maker says otherwise, follow them; this page explains general practice.
- Older aircraft may carry heads no longer made. The universal head may replace round, flat and brazier heads as AC 43.13-1B par. 4-57a(4) allows.
Where to buy
AmericaDistributor coming soonOur partner for this region is on its way
EuropeDistributor coming soonOur partner for this region is on its way
OceaniaDistributor coming soonOur partner for this region is on its way
Distributors coming soon.
Sources
- FAA-H-8083-31B, Aviation Maintenance Technician Handbook: Airframe, Chapter 4 — pp. 4-30, 4-31, Figs. 4-74, 4-75.
- FAA AC 43.13-1B CHG 1, Acceptable Methods, Techniques and Practices — par. 4-57a, rivet identification; Fig. 4-4; Table 4-8.
Educational reference only. not approved data. Always consult the applicable SRM, AMM, or AC 43.13-1B and your certifying authority.