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Solid Rivet Sizes, Drill Sizes and Length

Guide · Updated October 28, 2026

Solid rivets join sheet metal by upsetting the shank into a second head, called the shop head or bucktail. The hole is drilled a few thousandths over the rivet so it slides in, and the rivet swells to fill the hole when it is driven. Rivets are called out with AN or MS numbers such as MS20470AD4-5, where the 4 is the diameter in 32nds (1/8 in) and the 5 is the length in 16ths (5/16 in). The drill sizes and formulas below follow the FAA Airframe Handbook (FAA-H-8083-31), AC 43.13-1B and the MIL-R-47196 hole table.

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Step by step

Choose the rivet diameter: A common rule is about three times the thickness of the thickest sheet, rounded to a standard size.
Drill the hole: Use the chart drill size; drill square to the surface and clamp the sheets together.
Deburr: Remove burrs from both sides and between the sheets.
Calculate the length: Length = grip + 1.5D, rounded up to the next 1/16 in.
Drive the rivet: Buck the shank until the shop head is about 1.5D wide and 0.5D high.
Inspect: Check the shop head with a rivet gage and look for cracks, tipping or a gap under the head.

Rivet drill size chart

1/16 (dash 2): #51 drill (0.067), hole 0.062 to 0.072
3/32 (dash 3): #40 (0.098), hole 0.093 to 0.103
1/8 (dash 4): #30 (0.1285), hole 0.125 to 0.135
5/32 (dash 5): #21 (0.159), hole 0.156 to 0.171
3/16 (dash 6): #11 (0.191), hole 0.187 to 0.202
1/4 (dash 8): F (0.257), hole 0.250 to 0.265

Hole limits are from MIL-R-47196A Table I. The #40, #30, #21, #11 drill sequence is the one given in the FAA Airframe Handbook and covers almost all light sheet metal work.

Length and shop head

Rivet length L = grip + 1.5D, where grip is the total thickness of all sheets
Round L up to the next 1/16 in
Driven shop head width: 1.5D (AC 43.13-1B gives this as a minimum)
Driven shop head height: 0.5D (minimum)
Universal head (MS20470) manufactured head: about 2D across

Edge distance and spacing

Common practice is a minimum edge distance of 2D from the hole center to the sheet edge (2.5D is preferred for countersunk rivets), rivet pitch of 3D minimum and usually 4D to 6D, and transverse pitch between rows of about 75% of the rivet pitch. Larger rivets need larger edge distances, so going up a size to repair an oversize hole may break edge distance.

Worked example: two 0.040 in sheets

Thickest sheet 0.040 in × 3 = 0.120 in, so use a 1/8 in rivet (dash 4). Grip = 0.080 in. Length = 0.080 + 1.5 × 0.125 = 0.080 + 0.1875 = 0.2675 in, rounded up to 5/16 in (dash 5). The rivet is MS20470AD4-5, drilled #30. Shop head should be at least 0.188 in across and 0.0625 in high. Minimum edge distance 0.250 in, pitch 0.375 to 0.750 in.

Worked example: 0.063 + 0.032 in

Thickest sheet 0.063 × 3 = 0.189, so use 3/16 in (dash 6), drill #11. Grip = 0.095 in. Length = 0.095 + 0.281 = 0.376 in, round up to 7/16 in (dash 7). Shop head: 0.281 in wide, 0.094 in high. If the 3/16 rivet is too big for the edge distance available, a 5/32 rivet in a #21 hole is the next choice: length = 0.095 + 0.234 = 0.329, use 3/8 in.

Rivet alloys and markings

AD rivets (2117-T4) have a dimple on the head and can be driven as received. A rivets (1100) are plain and soft. D (2017) and DD (2024) rivets are stronger but must be heat treated and kept cold before driving, which is why they are called icebox rivets. Use the alloy the drawing calls out.

Common problems

Drilling oversize or oblong holes, skipping the deburr, using a rivet that is too short so the shop head is thin, clinching the rivet over by holding the bucking bar at an angle, and cracking the shop head on hard rivets. Check hole size with pin gages and shop heads with a rivet gage.

FAQ

What drill size for a 1/8 rivet?

#30 (0.1285 in).

What drill size for a 3/32 rivet?

#40 (0.098 in).

How long should a rivet be?

Grip plus 1.5 times the diameter, rounded up to the next 1/16 in.

How do I check rivet hole size?

Check the gage itself before trusting a measurement: gage blocks set mics, calipers and indicators; build any stack free at gageblockcalc.com.

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General shop information only — follow your drawing, tool maker's data and your quality system.