Threading: Coil Inserts

Coil inserts are available for UNC, UNF, and metric threads on both milled and turned parts.


MILLED PARTS

UNC threads Minimum modeled diameter (in.) Maximum modeled diameter (in.) 75% hole drill size (in.) Maximum thread depth (in.)*
#2-56 0.089 0.096 0.094 0.30
#3-48 0.105 0.110 0.107 0.40
#4-40 0.117 0.125 0.120 0.40
#5-40 0.130 0.137 0.134 0.40
#6-32 0.145 0.152 0.147 0.60
#8-32 0.170 0.178 0.173 0.60
#10-24 0.199 0.208 0.203 0.65
#12-24 0.225 0.234 0.228 0.65
1/4-20 0.260 0.270 0.266 0.65
5/16-18 0.324 0.334 0.332 1.00
3/8-16 0.388 0.398 0.397 1.00
7/16-14 0.453 0.463 0.453 1.00
1/2-13 0.515 0.531 0.522 1.00
*Obstruction by other features of your part, lead-in treatments, or fixturing requirements may reduce the maximum depth of threads.
UNF threads Minimum modeled diameter (in.) Maximum modeled diameter (in.) 75% hole drill size (in.) >Maximum thread depth (in.)*
#2-64 0.089 0.095 0.093 0.30
#3-56 0.102 0.104 0.104 0.30
#4-48 0.116 0.123 0.120 0.40
#6-40 0.144 0.150 0.147 0.60
#8-36 0.170 0.177 0.173 0.60
#10-32 0.196 0.204 0.201 0.65
1/4-28 0.257 0.265 0.261 >0.65
5/16-24 0.321 0.329 0.325 1.00
3/8-24 0.384 0.391 0.388 1.00
7/16-20 0.448 0.456 0.452 1.00
1/2-20 0.510 0.519 0.515 1.00
*Obstruction by other features of your part, lead-in treatments, or fixturing requirements may reduce the maximum depth of threads.
Metric threads Minimum modeled diameter (mm) Maximum modeled diameter (mm) 75% hole drill size (mm) Maximum thread depth (mm)*
M2 x 0.4 2.08 2.13 2.11 5.08
M2.5 x 0.45 >2.54 2.64 2.60 7.62
M3 x 0.5 3.10 3.24 3.18 5.08
M3.5 x 0.6 3.68 3.78 3.70 15.24
M4 x 0.7 4.15 4.33 4.20 15.24
M5 x 0.8 5.17 5.37 5.27 16.51
M6 x 1.0 6.21 6.40 6.31 16.51
M8 x 1.25 8.27 8.48 8.38 25.40
M10 x 1.5 10.32 10.55 10.44 25.40
M12 x 1.75 12.38 12.64 12.51 25.40
*Obstruction by other features of your part, lead-in treatments, or fixturing requirements may reduce the maximum depth of threads.

TURNED PARTS

UNC threads Minimum modeled diameter (in.) Maximum modeled diameter (in.) 75% hole drill size (in.) Maximum thread depth (in.)
#2-56 0.090 0.096 0.094 0.3
#3-48 0.105 0.110 0.106 0.4
#4-40 0.117 0.125 0.120 0.4
#5-40 0.131 0.137 0.134 0.4
#6-32 0.145 0.153 0.147 0.4
#8-32 0.171 0.178 0.173 0.4
#10-24* 0.199 0.208 0.203 0.5
#12-24* 0.225 0.234 0.228 0.5
1/4-20* 0.261 0.270 0.266 0.5
*On-axis holes only
UNF threads Minimum modeled diameter (in.) Maximum modeled diameter (in.) 75% hole drill size (in.) Maximum thread depth (in.)
#2-64 0.089 0.095 0.093 0.30
#3-56 0.102 0.109 0.106 0.30
#4-48 0.116 0.123 0.120 0.40
#6-40 0.144 0.150 0.147 0.40
#8-36 0.170 0.177 0.173 0.40
#10-32 0.196 0.204 0.201 0.40
1/4-28* 0.257 0.265 0.261 0.50
5/16-24* 0.321 0.329 0.325 0.50
3/8-24* 0.384 0.391 0.388 0.50
7/16-20* 0.448 0.456 0.452 0.50
1/2-20* 0.510 0.519 0.515 0.50
*On-axis holes only
Metric threads Minimum modeled diameter (mm) Maximum modeled diameter (mm) 75% hole drill size (mm) Maximum thread depth (mm)
M2.5 x 0.45 2.59 2.69 2.65 7.62
M3 x 0.5 3.10 3.24 3.18 10.16
M3.5 x 0.6 3.68 3.78 3.70 10.16
M4 x 0.7 4.15 4.33 4.20 10.16
M5 x 0.8 5.17 5.37 5.27 10.16
M6 x 1.0* 6.21 6.40 6.31 12.70
M8 x 1.25* 8.27 8.48 8.38 12.70
*On-axis holes only