A punch is a tool for forcing a pin, bolt, or rivet in
or out of a hole. Punches are used with ball-peen hammers to remove
pins, align holes and mark locations of holes to be drilled. They are
available in a wide range of sizes in both high-carbon and alloy steels.
They are similar to nail sets in appearance, but do not have a cupped or
hollowed end. It is one of the most popular types of hand tools used for
variety of purposes. It is usually in the shape of a hard metal rod
having a shaped tip at one end and a blunt butt end at the other which
can be struck by a hammer. A punch as a tool exerts a significant amount
of striking force on a very small portion.
All punches are made from high grade metal alloys like steel, carbon
steel, alloy steel, aluminum steel, brass alloys etc . All punches are
made to be struck and are, therefore, made of hardened steel. Each type
of alloy is hardened and tempered for maximum durability and given
different finishes like black oxidized or brown or golden oxidized to
give a smooth metallic shine.
Types of punches
There are a wide variety of punches used in engineering and other
purposes, but often the basic purpose of a punch is to form the tip on
an object or a workpiece. The various types of punches are as follows:
punch: This type of punch is used make indentations in metals.
The shape of the punch is that of a long, tapered punch which is
beveled at the tip to form a point. It looks like a center punch but
a smaller version. Prick punch is considered to be a light to medium
duty tool and typically used to make location marks on an equipment
or a work piece. It is primarily used for the purposes of layout.
The indentation produced by a prick punch is smaller than a center
punch. When layout is complete, the indentation made with the help
of a prick punch can be enlarged using a center punch, which allows
for drilling. A prick punch's tip when viewed on a profile, has
sides at a 30-60 degree angle to one another.
punch: This type of punch is used to help in drilling
operations. They are similar to prick punches but they are bigger,
heavier, thicker and suitable for heavy duty work. As such, they are
made of specially selected steel, hardened and properly tempered.
The points that are used to form indentations on metal surface are
ground at a proper angle to give maximum service, and the tips are
accurately centered. Center punches give drill bits a true start
because if an indentation is not made by a center punch, there is
every chance that a drill bit is liable to "walk" across
the surface of the work instead of drilling a hole. A center punch's
tip when viewed on a profile, has sides at a 90 degree angle to one
punch: A pin punch is slightly different from a center or prick
punches. It is a driving hand tool, used to drive pins. These pins
are used to fix a fixture to a rotating shaft. Pin punches have a
hexagonal body, with a long, flat ended cylindrical section. They
have uniformly narrow shanks which can reach all the way through
alignment holes and other circular recesses. Pin punches are
available in various sizes and diameters.
punch: A drift punch is used in aligning rivet
holes/bolts/screws prior to inserting a fastener. It is in the shape
of a tapered rod, with the hammer acting on the large end of the
taper. The tapered end of a drift punch is put inside the
semi-aligned bolt holes of two separate objects, and then driven
into the hole. As it is driven inside, the tapered end forces the
two components into alignment, which allows for insertion of the
fastener easily. Heavy, tapered punches with blunt tips, drift
punches help in driving alignment pins out of equipment. They come
in a variety of sizes to match the diameters of pins.
punch: Their main purpose is to cut circular holes in gasket
material, plastics, rubber and even soft metal. They have
sharp-edged circular ends instead of pointed or blunt solid tips.
The are available in sets consisting of a variety of different size
punches for cutting various size holes.
punch: It is of a specific outer diameter that is non-tapered
and extends the entire length of the punch leaving aside the tip. A
transfer punch's basic purpose is to tightly fit the tolerances of
an existing hole and, when the punch is struck, it transfers the
center of that hole to another surface. It can be used to copy the
hole patterns in a part, or in set locations for threaded holes.
pin punch: Roll pin punches have long shafts and large striking
heads with hardened points. They are machined specially for removing
spring and roll pins. These type of punches are designed to apply
consistent pressure to the end of a pin, which help to driving it
straight through the hole. The ball centered on the punch tip helps
in assuring proper contact, and it removes damage to the pin or hole
wall. They are usually hot forged from alloy steel for maximum