| Tapping
Screws (Type A, AB, B) |
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Type
A point: A thread forming screw for use in thin metal .015
to .050 thick. Used with drilled, punched or nested holes in
sheet metal, resin impregnated plywood, asbestos combinations,
among others. Not recommended for new design. |
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Type
AB point: A thread forming screw combining locating point
of Type A with thread size and pitch of Type B. Normal limitations
of type B apply. |
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Type
B point: A thread forming screw for use in heavier metal
.050 to .200 thick. Larger root diameter with finer thread pitch
for light and heavy sheet metal non-ferrous castings, plastics,
impregnated plywoods, asbestos combinations, and other materials. |
| Thread
Cutting Screws (Type 1, 17, 23, 25, F) |
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Type
1 point: A thread cutting screw with single flute for general
use. Produces a fine standard machine screw thread for field
replacement. |
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Type
17 point: A thread cutting screw for wood with a coarse tapping
screw thread and a special long sharp point fluted to capture
chips. |
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Type
23 point: A thread cutting screw in the fine thread series
offering maximum thread cutting area and excellent chip clearing,
with minimum tightening torques. |
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Type
25 point: A thread cutting screw similar to type 23 point
except with coarse Type B thread. For plastics and other soft
materials with large chip clearing and cutting edges. |
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Type
F point: A thread cutting screw with machine screw thread
with blunt tapered point, having multi- cutting edges and chip
cavities. For heavy gauge sheet metal, aluminum, zinc and
lead die castings, cast iron, brass and plastic. |
Thread
Forming Screws (Type C, CA, Tri-Round, Lo-Driv)
Screws for Plastic (Tri-Round, Round) |
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Type
C point: A thread forming screw with either coarse or fine
pitch machine screw thread and blunt tapered point. Eliminates
chips and permits replacement with standard screw in the field.
Higher driving torque required. Usable in heavy sheet metal and
die castings. |
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Type
CA point: A thread forming screw with either coarse or fine
pitch machine screw thread. Same as Type C except with a Gimlet
point. The locating point works better than Type C where holes
between two adjoining pieces of sheet metal may be somewhat misaligned. |
|
Tri-Round: A
thread forming screw in mostly coarse machine screw threads. Three
vertexes perform a roll-forming process to form mating threads.
Much better thread forming than Type C or CA, and drives with less
torque. |
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Lo-Driv: A
thread forming screw in mostly coarse machine screw threads. The
point and body design requires low end-load for starting and
low drive torque for seating. The full 360 degree body above the
point provides excellent strip-to-drive ratios. |
