USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 2
(c) Body.
The threaded part of tap.
(d) Chamfer. The length at the front end of the threaded section,
cut or ground tapered and relieved of teeth.
(e) Cutting Face.
The leading side of the threaded part or land.
(f) External Center. The cone shaped front end of the tap. It is
necessary for manufacturing purposes and usually at the threaded ends of
small taps only.
(g) Flute.
The portion cut away between the threaded parts of the
lands.
(h) Heel.
The noncutting or following side of the land.
(i) Hook.
The
curved
cutting
side
of
the
flute.
Used
when
tapping some materials.
(j) Internal Center.
The small drilled countersunk conical hole
at the front end of the tap, made for manufacturing purposes.
(k) Interrupted Thread.
Taps with every other tooth along the
threaded part removed. Used on soft, stringy materials.
(l) Land.
The threaded part of the tap.
(m) Point
Diameter.
The
diameter
at
the
leading
end
of
the
chamfered portion.
(n) Radial.
The straight side of a flute which, if continued,
would pass through the center of the tap.
(o) Rake. The angle of the cutting side of the flute in relation
to an axial plane passing through the center of the tap.
(p) Relief.
The condition whereby metal is removed from behind
the cutting edge to produce clearance and reduce friction. Most taps have
the chamfer relieved, but some may not have relief on the external diameter
of the threads.
(q) Shank.
The part behind the threaded section of the tap.
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