Nutsert Size Chart
Quick answer: Nutsert and rivet-nut drill size depends on thread size, body style, grip range, and manufacturer. A #8-32 rivet nut might use a hole around 17/64 inch, while a 1/4-20 rivet nut may use 3/8 inch or 25/64 inch depending on the insert series and material thickness. Always verify against the insert manufacturer’s chart before drilling final parts.
Common UNC Nutsert Drill Size Chart
| Thread size | Common drill size | Decimal hole size | Typical note |
|---|---|---|---|
| 4-40 UNC | 3/16 in to #9 | 0.1875-0.1960 in | Small inserts; hole varies by grip range |
| 6-32 UNC | 7/32 in to #1 | 0.2188-0.2280 in | Common light-duty insert size |
| 8-32 UNC | 1/4 in to 17/64 in | 0.2500-0.2656 in | Verify body diameter before drilling |
| 10-24 UNC | 9/32 in to 19/64 in | 0.2812-0.2969 in | Coarse thread option |
| 10-32 UNC | 9/32 in to 19/64 in | 0.2812-0.2969 in | Fine thread option |
| 1/4-20 UNC | 3/8 in to 25/64 in | 0.3750-0.3906 in | Common garage fabrication size |
| 5/16-18 UNC | 1/2 in to 33/64 in | 0.5000-0.5156 in | Heavier insert size |
| 3/8-16 UNC | 9/16 in to 37/64 in | 0.5625-0.5781 in | Heavy-duty insert size |
| 1/2-13 UNC | 3/4 in to 51/64 in | 0.7500-0.7970 in | Large insert; manufacturer chart is essential |
Why Nutsert Hole Size Varies
A Nutsert has to collapse behind the parent material and clamp securely. Hole size changes with the insert series, round or hex body, grip range, material thickness, and whether the insert is designed for sheet metal, plastic, fiberglass, or thicker material. A hole that is too small can damage the insert during installation. A hole that is too large can spin or pull out.
Installation Checklist
- Identify the exact Nutsert series and thread size.
- Check the manufacturer’s drill chart for your grip range.
- Drill a test hole in scrap material first.
- Deburr the hole before installation.
- Use the correct mandrel and tool setting.
- Stop if the insert spins; do not keep tightening and enlarge the hole.
Related references: bolt chart with wrench size, socket sizes in order, and American wrench size chart.
Source Notes
Drill-size ranges were cleaned from the old chart and cross-checked against rivet-nut and AT-series Nutsert drill-size references. Treat this as a planning chart; the exact insert manufacturer’s data sheet controls the final hole size.
