The Complete Engineering Reference You'll Wish You Had Years Ago
A maintenance supervisor lost an entire production shift because he grabbed the wrong wing nut type for a chemical processing line. The nut cracked under vibration, leaked corrosive fluid onto a conveyor bearing, and shut down the whole plant for 14 hours.
That's the cost of treating hand-tightened fasteners as "simple" hardware.
Wing nuts, wing screws, and thumb screws are the unsung workhorses of tool-free assembly. They show up everywhere—from jig fixtures and machine guards to air duct connections and battery terminal clamps. Yet most engineers, machinists, and maintenance professionals never learn the four distinct types, the critical material differences, or the exact dimensional standards that separate a reliable joint from a catastrophic failure.
This is the guide that changes that.
You're about to get every specification, every dimensional table, every material consideration, and every selection principle codified in ANSI B18.17-1968 (R1983)—translated into a practical, story-driven reference you can use on the shop floor, at the design desk, or in a purchasing decision today and decades from now.
Wing Nuts: The Four Types That Change Everything
A wing nut is a nut with protruding wings designed for manual turning without a driver or wrench. That's the simple definition. The engineering reality is far more nuanced.
Wing nuts are classified on two axes:
- Type → Based on the method of manufacture
- Style → Based on design characteristics (wing height, base size)
Understanding both axes is critical because they determine strength, fatigue resistance, cost, and application suitability.
Type A — Cold Forged or Cold Formed Solid Nuts
Manufacturing method: Cold forging or cold forming from solid metal stock
Key characteristics:
- Solid construction — no joints, welds, or stamped components
- Wings of moderate height
- Available in Light, Regular, and Heavy series (depending on size)
- Highest fatigue resistance of all wing nut types
- Best suited for vibration environments and repeated use
Why it matters: Cold forging compresses the grain structure of the metal, creating a nut that is inherently stronger than one machined from bar stock. There are no weld points to crack, no sheet metal to fatigue, and no die-cast porosity to worry about.
Available sizes: #3 (0.0990") through ¾" (0.7500")
Type A Wing Nut — Dimensional Reference (ANSI B18.17-1968, R1983)
All dimensions in inches. Preferred sizes shown in bold context.
| Nominal Size | TPI | Series | Blank | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D (Between Wings) | E (Boss Dia.) | G (Boss Hgt.) |
|---|---|---|---|---|---|---|---|---|---|
| #3 (0.099) | 48, 56 | Hvy. | AA | 0.59–0.72 | 0.28–0.41 | 0.07–0.11 | 0.17–0.21 | 0.29–0.33 | 0.10–0.14 |
| #4 (0.112) | 40, 38 | Hvy. | AA | 0.59–0.72 | 0.28–0.41 | 0.07–0.11 | 0.17–0.21 | 0.29–0.33 | 0.10–0.14 |
| #5 (0.125) | 40, 44 | Lgt. | AA | 0.59–0.72 | 0.28–0.41 | 0.07–0.11 | 0.17–0.21 | 0.29–0.33 | 0.10–0.14 |
| Hvy. | A | 0.78–0.91 | 0.34–0.47 | 0.10–0.14 | 0.22–0.27 | 0.39–0.43 | 0.14–0.18 | ||
| #6 (0.138) | 32, 40 | Lgt. | AA | 0.59–0.72 | 0.28–0.41 | 0.07–0.11 | 0.17–0.21 | 0.29–0.33 | 0.10–0.14 |
| Hvy. | A | 0.78–0.91 | 0.34–0.47 | 0.10–0.14 | 0.22–0.27 | 0.39–0.43 | 0.14–0.18 | ||
| #8 (0.164) | 32, 36 | Lgt. | A | 0.78–0.91 | 0.34–0.47 | 0.10–0.14 | 0.22–0.27 | 0.39–0.43 | 0.14–0.18 |
| Hvy. | B | 0.97–1.10 | 0.43–0.57 | 0.14–0.18 | 0.26–0.33 | 0.45–0.50 | 0.17–0.22 | ||
| #10 (0.190) | 24, 32 | Lgt. | A | 0.78–0.91 | 0.34–0.47 | 0.10–0.14 | 0.22–0.27 | 0.39–0.43 | 0.14–0.18 |
| Hvy. | B | 0.97–1.10 | 0.43–0.57 | 0.14–0.18 | 0.26–0.33 | 0.45–0.50 | 0.17–0.22 | ||
| #12 (0.216) | 24, 28 | Lgt. | B | 0.97–1.10 | 0.43–0.57 | 0.14–0.18 | 0.26–0.33 | 0.45–0.50 | 0.17–0.22 |
| Hvy. | C | 1.12–1.25 | 0.53–0.66 | 0.17–0.21 | 0.32–0.39 | 0.51–0.58 | 0.20–0.25 | ||
| ¼ (0.250) | 20, 28 | Lgt. | B | 0.97–1.10 | 0.43–0.57 | 0.14–0.18 | 0.26–0.39 | 0.45–0.50 | 0.17–0.22 |
| Reg. | C | 1.12–1.25 | 0.53–0.66 | 0.17–0.21 | 0.32–0.39 | 0.51–0.58 | 0.20–0.25 | ||
| Hvy. | D | 1.31–1.44 | 0.65–0.79 | 0.20–0.24 | 0.42–0.48 | 0.64–0.70 | 0.26–0.30 | ||
| 5⁄16 (0.3125) | 18, 24 | Lgt. | C | 1.12–1.25 | 0.53–0.66 | 0.17–0.21 | 0.32–0.39 | 0.51–0.58 | 0.20–0.25 |
| Reg. | D | 1.31–1.44 | 0.65–0.79 | 0.20–0.24 | 0.42–0.48 | 0.64–0.70 | 0.26–0.30 | ||
| Hvy. | E | 1.81–1.94 | 0.87–1.00 | 0.26–0.33 | 0.54–0.65 | 0.86–0.93 | 0.35–0.39 | ||
| ⅜ (0.375) | 16, 24 | Lgt. | D | 1.31–1.44 | 0.65–0.79 | 0.20–0.24 | 0.42–0.48 | 0.64–0.70 | 0.26–0.30 |
| Reg. | E | 1.81–1.94 | 0.87–1.00 | 0.26–0.33 | 0.54–0.65 | 0.86–0.93 | 0.35–0.39 | ||
| 7⁄16 (0.4375) | 14, 20 | Lgt. | E | 1.81–1.94 | 0.87–1.00 | 0.26–0.33 | 0.54–0.65 | 0.86–0.93 | 0.35–0.39 |
| Hvy. | F | 2.62–2.76 | 1.31–1.44 | 0.34–0.40 | 0.80–0.90 | 1.13–1.19 | 0.51–0.55 | ||
| ½ (0.500) | 13, 20 | Lgt. | E | 1.81–1.94 | 0.87–1.00 | 0.26–0.33 | 0.54–0.65 | 0.86–0.93 | 0.35–0.39 |
| Hvy. | F | 2.62–2.76 | 1.31–1.44 | 0.34–0.40 | 0.80–0.90 | 1.13–1.19 | 0.51–0.55 | ||
| 9⁄16 (0.5625) | 12, 18 | Hvy. | F | 2.62–2.76 | 1.31–1.44 | 0.34–0.40 | 0.80–0.90 | 1.13–1.19 | 0.51–0.55 |
| ⅝ (0.625) | 11, 18 | Hvy. | F | 2.62–2.76 | 1.31–1.44 | 0.34–0.40 | 0.80–0.90 | 1.13–1.19 | 0.51–0.55 |
| ¾ (0.750) | 10, 16 | Hvy. | F | 2.62–2.76 | 1.31–1.44 | 0.34–0.40 | 0.80–0.90 | 1.13–1.19 | 0.51–0.55 |
Key insight: Notice how the nut blank sizes (AA through F) create a standardized progression. A "Blank B" nut has the same wing dimensions whether it's on a #8 Heavy or a #12 Light. This means wing strength is determined by blank size, not thread size—a critical distinction when engineering for load.
Type B — Hot Forged Solid Nuts
Manufacturing method: Hot forging from solid metal stock
Key characteristics:
- One-piece solid construction
- Available in two wing styles:
- Style 1 — Wings of moderate height
- Style 2 — High wings (taller profile for easier gripping)
- Largest available sizes of any wing nut type (up to ¾")
- Best manual grip due to generous wing proportions
- Well-suited for heavy-duty applications requiring frequent hand adjustment
Why it matters: Hot forging allows for larger, more complex wing shapes than cold forming. The Style 2 high-wing variant gives operators significantly more leverage for hand tightening—critical in applications where gloved hands or oily fingers make gripping difficult.
Type B Wing Nut — Style 1 (Moderate Height Wings)
| Nominal Size | TPI | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D (Between Wings) | E (Boss Dia.) | G (Boss Hgt.) |
|---|---|---|---|---|---|---|---|
| #5 (0.125) | 40 | 0.72–0.78 | 0.30–0.36 | 0.10–0.13 | 0.22–0.28 | 0.28–0.31 | 0.16–0.22 |
| #10 (0.190) | 24 | 0.91–0.97 | 0.39–0.45 | 0.12–0.15 | 0.28–0.34 | 0.36–0.39 | 0.22–0.28 |
| ¼ (0.250) | 20 | 1.09–1.16 | 0.50–0.56 | 0.14–0.17 | 0.34–0.41 | 0.44–0.47 | 0.28–0.34 |
| 5⁄16 (0.3125) | 18 | 1.38–1.44 | 0.61–0.67 | 0.15–0.18 | 0.44–0.50 | 0.52–0.55 | 0.34–0.41 |
| ⅜ (0.375) | 16 | 1.66–1.72 | 0.73–0.80 | 0.17–0.20 | 0.53–0.59 | 0.60–0.63 | 0.41–0.47 |
| 7⁄16 (0.4375) | 14 | 1.94–2.00 | 0.84–0.91 | 0.18–0.21 | 0.62–0.69 | 0.68–0.71 | 0.47–0.53 |
| ½ (0.500) | 13 | 2.22–2.31 | 0.94–1.06 | 0.20–0.23 | 0.69–0.78 | 0.76–0.79 | 0.50–0.62 |
| 9⁄16 (0.5625) | 12 | 2.47–2.59 | 1.05–1.17 | 0.21–0.25 | 0.78–0.88 | 0.84–0.88 | 0.56–0.69 |
| ⅝ (0.625) | 11 | 2.72–2.84 | 1.19–1.31 | 0.23–0.27 | 0.84–0.94 | 0.92–0.96 | 0.62–0.75 |
| ¾ (0.750) | 10 | 3.19–3.31 | 1.39–1.52 | 0.25–0.29 | 1.00–1.10 | 1.08–1.12 | 0.75–0.88 |
Type B Wing Nut — Style 2 (High Wings)
| Nominal Size | TPI | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D (Between Wings) | E (Boss Dia.) | G (Boss Hgt.) |
|---|---|---|---|---|---|---|---|
| #5 (0.125) | 40 | 0.75–0.81 | 0.56–0.62 | 0.09–0.12 | 0.22–0.28 | 0.28–0.31 | 0.16–0.22 |
| #10 (0.190) | 24 | 0.95–1.01 | 0.72–0.78 | 0.11–0.14 | 0.29–0.35 | 0.36–0.39 | 0.22–0.28 |
| ¼ (0.250) | 20 | 1.16–1.22 | 0.88–0.94 | 0.13–0.16 | 0.35–0.41 | 0.44–0.47 | 0.28–0.34 |
| 5⁄16 (0.3125) | 18 | 1.37–1.43 | 1.03–1.09 | 0.14–0.17 | 0.42–0.48 | 0.52–0.55 | 0.34–0.41 |
| ⅜ (0.375) | 16 | 1.57–1.63 | 1.19–1.25 | 0.15–0.18 | 0.49–0.55 | 0.60–0.63 | 0.41–0.47 |
| 7⁄16 (0.4375) | 14 | 1.84–1.90 | 1.36–1.42 | 0.16–0.19 | 0.56–0.62 | 0.68–0.71 | 0.47–0.53 |
| ½ (0.500) | 13 | 2.04–2.13 | 1.45–1.58 | 0.17–0.20 | 0.60–0.69 | 0.76–0.79 | 0.50–0.62 |
| 9⁄16 (0.5625) | 12 | 2.28–2.40 | 1.62–1.75 | 0.18–0.22 | 0.67–0.76 | 0.84–0.88 | 0.56–0.69 |
| ⅝ (0.625) | 11 | 2.48–2.60 | 1.78–1.91 | 0.19–0.23 | 0.74–0.83 | 0.92–0.96 | 0.62–0.75 |
| ¾ (0.750) | 10 | 2.90–3.02 | 2.09–2.22 | 0.20–0.24 | 0.88–0.97 | 1.08–1.12 | 0.75–0.88 |
Design tip: Compare the wing height (B) between Style 1 and Style 2 at the ¼" size. Style 1 gives you 0.50–0.56" of wing height. Style 2 gives you 0.88–0.94". That's nearly double the gripping surface—a massive ergonomic advantage when operators wear thick gloves.
Type C — Die Cast Solid Nuts
Manufacturing method: Die casting (zinc alloy)
Key characteristics:
- Die cast construction — complex shapes with tight tolerances
- Available in three wing styles:
- Style 1 — Wings of moderate height (Light, Regular, and Heavy series in some sizes)
- Style 2 — Low wings
- Style 3 — High wings
- Material is always die cast zinc alloy (no steel or brass options)
- Tightest dimensional tolerances of all wing nut types
- Best suited for high-volume, light-duty applications
Why it matters: Die casting produces dimensionally consistent parts with excellent surface finish. The tradeoff is material—zinc alloy is weaker and less corrosion-resistant than steel or brass. Type C nuts are not recommended for corrosive environments, high-temperature applications, or heavy structural loads.
Type C Wing Nut — Style 1 (Moderate Height Wings)
| Nominal Size | TPI | Series | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D (Between Wings) | E (Boss Dia.) | F (Boss Dia.) | G (Boss Hgt.) |
|---|---|---|---|---|---|---|---|---|---|
| #4 (0.112) | 40 | Reg. | 0.64–0.66 | 0.35–0.36 | 0.09–0.11 | 0.16–0.18 | 0.25–0.27 | 0.30–0.32 | 0.14–0.16 |
| #5 (0.125) | 40 | Reg. | 0.64–0.66 | 0.35–0.36 | 0.09–0.11 | 0.16–0.18 | 0.25–0.27 | 0.30–0.32 | 0.14–0.16 |
| #6 (0.138) | 32 | Reg. | 0.64–0.66 | 0.35–0.36 | 0.09–0.11 | 0.16–0.18 | 0.25–0.27 | 0.30–0.32 | 0.14–0.16 |
| Hvy. | 0.83–0.85 | 0.42–0.43 | 0.12–0.14 | 0.27–0.29 | 0.36–0.38 | 0.40–0.41 | 0.18–0.20 | ||
| #8 (0.164) | 32 | Reg. | 0.83–0.85 | 0.42–0.43 | 0.12–0.14 | 0.27–0.29 | 0.36–0.38 | 0.40–0.41 | 0.18–0.20 |
| #10 (0.190) | 24, 32 | Reg. | 0.83–0.85 | 0.42–0.43 | 0.12–0.14 | 0.27–0.29 | 0.36–0.38 | 0.40–0.41 | 0.18–0.20 |
| #12 (0.216) | 24 | Reg. | 0.83–0.85 | 0.42–0.43 | 0.12–0.14 | 0.27–0.29 | 0.36–0.38 | 0.40–0.41 | 0.18–0.20 |
| Hvy. | 1.05–1.08 | 0.53–0.57 | 0.14–0.16 | 0.30–0.32 | 0.42–0.44 | 0.46–0.48 | 0.21–0.23 | ||
| ¼ (0.250) | 20, 28 | Reg. | 1.05–1.08 | 0.53–0.57 | 0.14–0.16 | 0.30–0.32 | 0.42–0.44 | 0.46–0.48 | 0.21–0.23 |
| 5⁄16 (0.3125) | 18, 24 | Reg. | 1.20–1.23 | 0.62–0.64 | 0.18–0.20 | 0.35–0.39 | 0.49–0.50 | 0.55–0.57 | 0.24–0.26 |
| ⅜ (0.375) | 16, 24 | Reg. | 1.42–1.45 | 0.72–0.74 | 0.21–0.23 | 0.42–0.46 | 0.60–0.62 | 0.67–0.69 | 0.27–0.29 |
| 7⁄16 (0.4375) | 14, 20 | Reg. | 1.86–1.89 | 0.90–0.91 | 0.28–0.29 | 0.65–0.67 | 0.73–0.75 | 0.82–0.83 | 0.37–0.38 |
| Hvy. | 1.86–1.89 | 0.91–0.93 | 0.33–0.34 | 0.62–0.63 | 0.79–0.81 | 0.87–0.89 | 0.40–0.42 | ||
| ½ (0.500) | 13, 20 | Reg. | 1.86–1.89 | 0.90–0.91 | 0.28–0.29 | 0.65–0.67 | 0.73–0.75 | 0.82–0.83 | 0.37–0.38 |
| Hvy. | 1.86–1.89 | 0.91–0.93 | 0.33–0.34 | 0.62–0.63 | 0.79–0.81 | 0.87–0.89 | 0.40–0.42 |
Type C Wing Nut — Style 2 (Low Wings)
| Nominal Size | TPI | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D (Between Wings) | E (Boss Dia.) | G (Boss Hgt.) |
|---|---|---|---|---|---|---|---|
| #5 (0.125) | 40 | 0.80–0.82 | 0.23–0.25 | 0.08–0.09 | 0.19–0.21 | 0.24–0.26 | 0.15–0.17 |
| #6 (0.138) | 32 | 0.80–0.82 | 0.23–0.25 | 0.08–0.09 | 0.19–0.21 | 0.24–0.26 | 0.15–0.17 |
| #8 (0.164) | 32 | 0.99–1.01 | 0.27–0.28 | 0.09–0.11 | 0.28–0.29 | 0.34–0.36 | 0.18–0.19 |
| #10 (0.190) | 24, 32 | 0.99–1.01 | 0.27–0.28 | 0.09–0.11 | 0.28–0.29 | 0.34–0.36 | 0.18–0.19 |
| #12 (0.216) | 24 | 1.18–1.20 | 0.31–0.32 | 0.11–0.12 | 0.37–0.38 | 0.43–0.44 | 0.20–0.22 |
| ¼ (0.250) | 20 | 1.18–1.20 | 0.31–0.32 | 0.11–0.12 | 0.37–0.38 | 0.43–0.44 | 0.20–0.22 |
| 5⁄16 (0.3125) | 18 | 1.49–1.51 | 0.35–0.36 | 0.12–0.14 | 0.43–0.44 | 0.49–0.51 | 0.23–0.24 |
| ⅜ (0.375) | 16 | 1.86–1.89 | 0.55–0.58 | 0.17–0.20 | 0.43–0.44 | 0.62–0.63 | 0.35–0.37 |
Type C Wing Nut — Style 3 (High Wings)
| Nominal Size | TPI | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D (Between Wings) | E (Boss Dia.) | G (Boss Hgt.) |
|---|---|---|---|---|---|---|---|
| #5 (0.125) | 40 | 0.89–0.92 | 0.67–0.70 | 0.15–0.16 | 0.24–0.26 | 0.36–0.38 | 0.24–0.25 |
| #6 (0.138) | 32 | 0.89–0.92 | 0.67–0.70 | 0.15–0.16 | 0.24–0.26 | 0.36–0.38 | 0.24–0.25 |
| #8 (0.164) | 32 | 0.89–0.92 | 0.67–0.70 | 0.15–0.16 | 0.24–0.26 | 0.36–0.38 | 0.24–0.25 |
| #10 (0.190) | 24, 32 | 1.12–1.14 | 0.83–0.85 | 0.17–0.19 | 0.30–0.32 | 0.42–0.44 | 0.27–0.29 |
| #12 (0.216) | 24 | 1.12–1.14 | 0.83–0.85 | 0.17–0.19 | 0.30–0.32 | 0.42–0.44 | 0.27–0.29 |
| ¼ (0.250) | 20 | 1.12–1.14 | 0.83–0.85 | 0.17–0.19 | 0.30–0.32 | 0.42–0.44 | 0.27–0.29 |
| 5⁄16 (0.3125) | 18 | 1.27–1.29 | 1.02–1.04 | 0.22–0.23 | 0.36–0.39 | 0.49–0.50 | 0.34–0.35 |
| ⅜ (0.375) | 16 | 1.49–1.51 | 1.18–1.20 | 0.25–0.27 | 0.42–0.45 | 0.60–0.62 | 0.42–0.43 |
Type D — Stamped Sheet Metal Nuts
Manufacturing method: Stamped from sheet metal
Key characteristics:
- Lowest cost of all wing nut types
- Three styles available: Style 1 (moderate wings), Style 2 (low wings), Style 3 (moderate wings with larger bearing surface)
- Thinnest construction — stock thickness ranges from 0.03 to 0.08 inches
- Modified Class 2B thread — minor diameter may be larger than standard Class 2B maximum
- Least fatigue resistant — the stamped construction creates stress concentrators at wing roots
Why it matters: This is the type that caused the practitioner's failure at Graystone. Type D nuts are perfectly adequate for static, low-vibration, infrequent-removal applications. But their thin stamped construction makes them vulnerable to fatigue cracking in any application involving repeated hand tightening, vibration, or thermal cycling.
Type D Wing Nut — Style 1
| Nominal Size | TPI | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D Min (Between Wings) | E (Boss Dia.) | G Min (Boss Hgt.) | H Min (Wall Hgt.) | T (Stock Thick.) |
|---|---|---|---|---|---|---|---|---|---|
| #8 (0.164) | 32, 36 | 0.72–0.78 | 0.34–0.40 | 0.14–0.18 | 0.25 | 0.35–0.41 | 0.08 | 0.12 | 0.03–0.04 |
| #10 (0.190) | 24, 32 | 0.85–0.91 | 0.41–0.47 | 0.17–0.21 | 0.34 | 0.47–0.53 | 0.10 | 0.12 | 0.03–0.04 |
| #12 (0.216) | 24, 28 | 1.03–1.09 | 0.41–0.47 | 0.17–0.21 | 0.34 | 0.47–0.53 | 0.10 | 0.12 | 0.04–0.05 |
| ¼ (0.250) | 20, 28 | 1.05–1.11 | 0.44–0.50 | 0.21–0.25 | 0.34 | 0.56–0.62 | 0.11 | 0.12 | 0.04–0.05 |
| 5⁄16 (0.3125) | 18, 24 | 1.24–1.30 | 0.53–0.59 | 0.26–0.30 | 0.46 | 0.67–0.73 | 0.14 | 0.18 | 0.05–0.06 |
| ⅜ (0.375) | 16, 24 | 1.34–1.41 | 0.61–0.67 | 0.30–0.34 | 0.69 | 0.77–0.83 | 0.16 | 0.18 | 0.05–0.06 |
Type D Wing Nut — Style 2 (Low Wings)
| Nominal Size | TPI | Series | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D Min | E (Boss Dia.) | G Min | H Min | T (Stock) |
|---|---|---|---|---|---|---|---|---|---|---|
| #5 (0.125) | 40 | Reg. | 0.97–1.03 | 0.19–0.25 | 0.13–0.19 | 0.30 | 0.34–0.40 | 0.07 | 0.09 | 0.03–0.04 |
| #6 (0.138) | 32 | Reg. | 0.97–1.03 | 0.19–0.25 | 0.13–0.19 | 0.30 | 0.34–0.40 | 0.08 | 0.09 | 0.03–0.04 |
| #8 (0.164) | 32 | Reg. | 0.97–1.03 | 0.19–0.25 | 0.13–0.19 | 0.30 | 0.34–0.40 | 0.08 | 0.09 | 0.03–0.04 |
| #10 (0.190) | 24, 32 | Reg. | 1.34–1.40 | 0.28–0.34 | 0.18–0.25 | 0.32 | 0.47–0.53 | 0.09 | 0.16 | 0.04–0.05 |
| Hvy. | 1.16–1.21 | 0.26–0.28 | 0.25–0.31 | 0.60 | 0.55–0.61 | 0.09 | 0.13 | 0.04–0.05 | ||
| #12 (0.216) | 24 | Reg. | 1.16–1.21 | 0.26–0.28 | 0.25–0.31 | 0.60 | 0.55–0.61 | 0.11 | 0.13 | 0.04–0.05 |
| ¼ (0.250) | 20 | Reg. | 1.16–1.21 | 0.26–0.28 | 0.25–0.31 | 0.60 | 0.55–0.61 | 0.11 | 0.13 | 0.04–0.05 |
Type D Wing Nut — Style 3 (Moderate Wings, Larger Base)
| Nominal Size | TPI | Series | A (Wing Spread) | B (Wing Height) | C (Wing Thick.) | D Min | E (Boss Dia.) | G Min | H Min | T (Stock) |
|---|---|---|---|---|---|---|---|---|---|---|
| #10 (0.190) | 24, 32 | Lgt. | 1.25–1.31 | 0.42–0.48 | 0.23–0.29 | 0.47 | 0.59–0.65 | 0.08 | 0.12 | 0.03–0.04 |
| Reg. | 1.34–1.40 | 0.47–0.53 | 0.19–0.25 | 0.50 | 0.69–0.75 | 0.08 | 0.14 | 0.03–0.04 | ||
| #12 (0.216) | 24 | Reg. | 1.22–1.28 | 0.34–0.40 | 0.17–0.23 | 0.59 | 0.67–0.73 | 0.11 | 0.12 | 0.03–0.04 |
| ¼ (0.250) | 20 | Lgt. | 1.22–1.28 | 0.34–0.40 | 0.17–0.23 | 0.59 | 0.67–0.73 | 0.11 | 0.12 | 0.03–0.04 |
| Reg. | 1.72–1.78 | 0.60–0.66 | 0.25–0.31 | 0.70 | 0.97–1.03 | 0.14 | 0.17 | 0.04–0.06 | ||
| Hvy. | 1.40–1.47 | 0.44–0.50 | 0.31–0.37 | 0.66 | 0.97–1.03 | 0.14 | 0.14 | 0.06–0.08 | ||
| 5⁄16 (0.3125) | 18 | Reg. | 1.72–1.78 | 0.60–0.66 | 0.25–0.31 | 0.70 | 0.97–1.03 | 0.14 | 0.17 | 0.04–0.06 |
| Hvy. | 1.40–1.47 | 0.44–0.50 | 0.31–0.37 | 0.66 | 0.97–1.03 | 0.14 | 0.14 | 0.06–0.08 |
The Wing Nut Type Comparison Matrix
This is the table the practitioner wished he'd had before the failure. Print it. Laminate it. Put it on the wall of your maintenance shop.
| Feature | Type A (Cold Forged) | Type B (Hot Forged) | Type C (Die Cast) | Type D (Stamped) |
|---|---|---|---|---|
| Construction | Solid, cold formed | Solid, hot forged | Solid, die cast | Sheet metal, stamped |
| Strength | ★★★★★ | ★★★★★ | ★★★☆☆ | ★★☆☆☆ |
| Fatigue Resistance | ★★★★★ | ★★★★☆ | ★★★☆☆ | ★☆☆☆☆ |
| Dimensional Consistency | ★★★★☆ | ★★★☆☆ | ★★★★★ | ★★★☆☆ |
| Cost | ★★★☆☆ | ★★☆☆☆ | ★★★★☆ | ★★★★★ |
| Material Options | Carbon steel, brass, stainless | Carbon steel, brass, stainless | Zinc alloy only | Carbon steel, brass, stainless |
| Max Thread Size | ¾" | ¾" | ½" | ⅜" (Style 1); ¼" (Style 2) |
| Wing Styles | 1 style (moderate) | 2 styles | 3 styles | 3 styles |
| Series Options | Lgt./Reg./Hvy. | None | Lgt./Reg./Hvy. (some) | Lgt./Reg./Hvy. (some) |
| Thread Class | 2B | 2B | 2B | Modified 2B |
| Best For | Vibration, repeated use, critical joints | Heavy-duty, large sizes, gloved operation | High-volume, light-duty, consumer products | Static applications, low cost, one-time assembly |
| Avoid For | Cost-sensitive non-critical apps | Small sizes, tight budgets | Corrosive environments, structural loads | Vibration, thermal cycling, repeated removal |
How to Specify Wing Nuts (The Right Way)
the practitioner's original purchase orders said: "Wing nuts, quarter-inch."
That tells the supplier almost nothing. Here's what a proper wing nut specification looks like:
Specification Sequence (per ANSI B18.17-1968)
Nominal Size → Threads Per Inch → Type → Style and/or Series → Material → Finish
Correct Specification Examples
10–32 Type A Wing Nut, Regular Series, Steel, Zinc Plated0.250–20 Type C Wing Nut, Style 1, Zinc Alloy, Plain⅜–16 Type B Wing Nut, Style 2, Brass, Plain¼–20 Type A Wing Nut, Heavy Series, Corrosion Resistant Steel, Plain
The Specification Checklist
Every wing nut callout must include:
- Nominal size — number (#3, #10, etc.), fraction (¼, ⅜, etc.), or decimal (0.250)
- Threads per inch — must match the specific TPI for the type and size
- Type — A, B, C, or D
- Style — Required for Types B (1 or 2), C (1, 2, or 3), and D (1, 2, or 3)
- Series — Light, Regular, or Heavy (where applicable)
- Material — Carbon steel, brass, corrosion resistant steel, or zinc alloy (Type C)
- Finish — Plain (unplated/uncoated) is default; specify if plating is required
Threads for Wing Nuts
Standard Thread Compliance
Types A, B, and C wing nuts use threads conforming to ANSI Standard Unified Thread, Class 2B.
Type D wing nuts use a modified Class 2B thread. Because of the stamping manufacturing process, the minor diameter of the thread in Type D nuts may be somewhat larger than the Unified Thread Class 2B maximum—but it must never exceed the minimum pitch diameter.
What this means practically: Type D nuts have slightly looser thread engagement than the other three types. This further reduces their clamping consistency and vibration resistance. If you're replacing Type A, B, or C nuts with Type D, the thread fit will feel "sloppier" on the bolt—and that's by design, not a defect.