| Thread
Cutting Screw
The off-center
shank slot on these case-hardened screws provided the first
type of thread-forming fastener. The various slot designs
provide true cutting action, cleanly removing the mating
metal as it is installed - eliminating a separate tapping
operation and generating a perfectly mated thread that contributes
to a stronger fastening.
Over the years, several types of thread cutters have been
designed for specific applications and materials.
- Type
1 thread cutting screws are recommended for steel parts
having a thickness less than half of the screw diameter.
- The
Type 23 thread cutting screw, with its wider shank slot.
is recommended for use in cast iron and soft metals such
as zinc and aluminum castings -and in some plastics.
- The
Type 25 thread cutting screw, combining a wide thread
cutting shank slot and acute cutting edge with spaced
threads for low driving/high stripping torque is ideal
for cutting mating threads in thermoset plastic materials.
- The
Type 17 screw will drill its own hole and cut close mating
threads in wood. light plastics and particle board.
|
Recommended
Pilot Hole Sizes - Thread Cutting Screws -Steel
| Steel
Thickness |
Screw
Size |
| 4-40 |
6-32 |
8-32 |
10-24 |
10-32 |
1/4
-20 |
1/4
- 28 |
5/16-18 |
5/16
- 24 |
3/8
- 16 |
3/8
- 24 |
| Up To
.047 |
.089 |
.110 |
.136 |
.154 |
.161 |
.205 |
|
|
|
|
|
| .063 |
.089 |
.111 |
.136 |
.154 |
..166 |
209 |
|
.2656 |
.277 |
..323 |
339 |
| .078 |
.093 |
.113 |
.140 |
.1562 |
.166 |
.209 |
.221 |
.2656 |
.277 |
.323 |
.3438 |
| .094 |
.093 |
.116 |
.140 |
.159 |
.166 |
.213 |
.228 |
.272 |
.2812 |
.332 |
.348 |
| .109 |
,093 |
.116 |
.144 |
161 |
.169 |
.213 |
.228 |
.272 |
.2812 |
..332 |
348 |
| .125 |
.096 |
.120 |
.144 |
.166 |
.169 |
.2188 |
.228 |
.277 |
.290 |
.339 |
.348 |
| .141 |
.098 |
.120 |
.144 |
.166 |
.169 |
.2188 |
.228 |
.277 |
.290 |
.339 |
.348 |
| .188 |
.101 |
.125 |
.147 |
.166 |
.1719 |
.221 |
.228 |
.277 |
.290 |
.339 |
.348 |
| .250 |
.104 |
.128 |
.154 |
.177 |
.180 |
.234 |
.238 |
.295 |
.2969 |
.358 |
.3594 |
| .313 |
|
.128 |
.154 |
.177 |
.180 |
.234 |
.238 |
.295 |
.2969 |
.358 |
.3594 |
| Up To
.375 |
|
|
|
.177 |
|
.234 |
|
.295 |
.2969 |
.358 |
.3594 |
Recommended
Pilot Hole Sizes - Thread Cutting Screws -Plastic
| Cellulose
Compounds |
Phenolics,
Polystyrene,Urethane,Compounds |
| Type23 |
Type25 |
Type23 |
Type25 |
| Screw
Size |
DIA. |
Screw
Size |
DIA. |
Screw
Size |
DIA. |
Screw
Size |
DIA. |
| 4-40 |
.0980 |
4-24 |
.0995 |
4-40 |
.0995 |
4-24 |
.1040 |
| 6-32 |
.1200 |
6-20 |
.1200 |
6-32 |
.1250 |
6-20 |
.1250 |
| 8-32 |
.1440 |
8-18 |
.1440 |
8-32 |
.1470 |
8-18 |
.1470 |
| 10-24 |
.1660 |
10-16 |
.1660 |
10-24 |
.1695 |
10-16 |
.1695 |
| 1/4-20 |
.2210 |
1/4-14 |
.2210 |
1/4-20 |
.2280 |
1/4-14 |
.2280 |
| 5/16-18 |
.2770 |
5/16-12 |
.2770 |
5/16-18 |
.2812 |
5/16-12 |
.2900 |
| 3/8-16 |
.3390 |
3/8-12 |
.3438 |
3/8-16 |
.3438 |
3/8-12 |
3438 |
|
Sizes: M4 - M14- Various Head and Recess
Styles
Flat, Conical, or Square Cone Washer Optional
Finishes: 0 -1000 hour |
|
|
|