Drill Reference Chart

Use the reference chart below to correctly size your holes for drills and hardware.

How to use this chart

Find your drill or hardware thread size. The recommended close/free fit will be the size of your hole. Use the free size for a looser fit and close for a tight fit.

If you are countersinking, the close/free fit sizes will apply to your minor diameter.

Imperial Drill Sizes

Screw/
Thread
Size
Thread
Size
Examples
Major
Diameter
Close/Free
Fit
44-40.112″.117″ – .129″
66-32.138″.144″ – .150″
88-32.164″.169″ – .177″
1010-32.190″.196″ – .201″
1/41/4-20, 1/4-28.250″.257″ – .266″
5/165/16-18, 5/16-24.313″.323″ – .332″
3/83/8-16, 3/8-24.375″.386″ – .397″
7/167/16-14,7/16-20, 7/16-28.438″.453″ – .469″
1/21/2-13, 1/2-20, 1/2-28.500″.516″ – .533″
9/169/16-12, 9/16-18.556″.578″ – .594″
5/85/8-11, 5/8-18, 5/8-24.625″.640″ – .659″
11/1611/16-18, 11/16-24.688″.703″ – .723″
3/43/4-10, 3/4-16, 3/4-20.750″.766″ – .795″
13/1613/16-16, 13/16-20.813″.828″ – .862″
7/87/8-9, 7/8-14, 7/8-20.875″.891″ – .925″
15/1615/16-16, 15/16-20.938″.953” – .990″
11-8, 1-121.000″1.016″ – 1.1065″

Imperial Drill Sizes

Screw/
Thread
Size
Thread
Size
Examples
Major
Diameter
(MM)
Close/Free
Fit
(MM)
44-402.8452.972 – 3.277
66-323.5053.658 – 3.810
88-324.1664.293 – 4.496
1010-324.8264.978 – 5.105
1/41/4-20, 1/4-286.3506.528 – 6.756
5/165/16-18, 5/16-247.9508.204 – 8.433
3/83/8-16, 3/8-249.5259.804 – 10.084
7/167/16-14,7/16-20, 7/16-2811.11311.506 – 11.913
1/21/2-13, 1/2-20, 1/2-2812.70013.106 – 13.538
9/169/16-12, 9/16-1814.12914.684 – 15.083
5/85/8-11, 5/8-18, 5/8-2415.87516.256 – 16.739
11/1611/16-18, 11/16-2417.46317.859 – 18.364
3/43/4-10, 3/4-16, 3/4-2019.05019.446 – 20.193
13/1613/16-16, 13/16-2020.63821.034 – 21.895
7/87/8-9, 7/8-14, 7/8-2022.22522.621 – 23.495
15/1615/16-16, 15/16-2023.81324.209 – 25.146
11-8, 1-1225.40025.796 – 27.051

Hardware insertion and hole features

Countersinking

For flush surfaces, there’s countersinking. Increase the lifespan of your part and preserve your hardware from long-term wear.

Hardware Insertion

Let SendCutSend and PEM fasteners set your parts up for success with self-clinching nuts, studs, and stand-offs.

Tapping

Utilizing specialized, automated equipment, we precisely laser-cut a hole, create some threading, and send you on your way with your completed part.

Start your first SendCutSend project today!

Upload your CAD design or use our parts builder and get a free instant quote on your custom laser cut parts, all delivered to your door in a matter of days.
No CAD File? No Problem! Send your sketch or template to our Design Services team. Starting at $49.

We proudly use hardware by PEM

Flush stud, M8 x 1.25, .472" Zinc plus Clear Chromate

Aluminum: 5052, 6061, 7075 Steel: Mild

SKUFH-M8-12
Thread SizeM8 x 1.25
Hole size in sheet (+0.003/-.0.000).315″
Minimum sheet thickness0.094″
Maximum sheet thickness.347″
Fastener materialSteel
Minimum distance hole C/L to edge0.378″
Minimum distance between two of the same hardware.567″
Recommended panel materialSteel/Aluminum
Coating typeZinc
Length.472″
Aluminum material ranges (5052, 6061, 7075)0.100″-0.250″
Steel material ranges (CRS, HRPO, HR)0.104″-0.250″

Get an Instant Quote for Waterjet Cutting

We proudly use hardware by PEM

Flush Standoff, 4-40, .250" Zinc plus Clear Chromate

Aluminum: 5052, 6061, 7075 Steel: Mild, G30

SKUSO-440-8
Thread Size4-40 x .250″
Hole size in sheet (+0.003/-.0.000).168″
Minimum sheet thickness0.040″
Maximum sheet thickness.125″
Fastener materialSteel
Minimum distance hole C/L to edge0.230″
When determining the distance between two or more fasteners, you can calculate the distance by the formula, C/L to edge + 1/2 the diameter of the second mounting hole..345″
Recommended panel materialSteel/Aluminum
Coating typeZinc
Length.250″
Aluminum material ranges (5052, 6061, 7075)0.040″-0.125″
Steel material ranges (CRS, HRPO, HR)0.048″-0.119″

We proudly use hardware by PEM

Flush Standoff, 4-40, .250" Passivated

Stainless Steel: 304, 316

SKUSO4-440-8
Thread Size440
Hole size in sheet (+0.003/-.0.000).166″
Minimum sheet thickness0.04″
Maximum sheet thickness.125″
Fastener material400 Stainless Steel
Minimum distance hole C/L to edge0.230″
When determining the distance between two or more fasteners, you can calculate the distance by the formula, C/L to edge + 1/2 the diameter of the second mounting hole. Example shown with x2 of the same hardware..313″
Recommended panel materialStainless Steel
Coating typePassivated
Length.250″
304 Stainless Steel material ranges0.048″-0.125″
316 Stainless Steel material ranges0.060″-0.125″