Sub Module 7.3: Hammers
EASA MODULE 7A
Sub Module 7.3
TOOLS
HAMMERS:
Hammers are classified by their weight and type of head. Steel heads are forged and manufactured from high-carbon steel. Most shafts are made from straight-grained Ash or Hickory and are secured to the head by wedging.
The main types of engineering hammers are :
Ball Pein: The flat surface is used for most general-purpose work whilst the ball pein is used primarily for riveting-type operations.
Cross Pein: As for the straight pein, but the axis of the pein is at 90° to that of the shaft.
Hide/Copper Face: The rawhide
facing enables heavy blows to be delivered without damaging the surface
of the work, while the copper face may be used for heavier types of work
than hide faced hammers.
Rubber Head and Plastic Face: More modern versions of the Hide Face hammer. Can often have one of each type of face on each end of the head.
Claw Hammer: More commonly used for woodworking. The face is used for hammering nails whilst
the claw is used for removing nails.
The weight of hammer required can be found with experience. Before use, it must be ensured that the head is secure on the shaft. The shaft should be gripped close to the end opposite the head, as proper control is not possible if it is held close to the head.
EASA ESSAY QUESTION:
What are different types of punches and how they can be helpful during maintenance of aircraft ?
(Note: write your answers in the comment section below)
Punches are not pounding tools infact they concentrate the force of a hammer to one point.
ReplyDeletePunches are used in conjunction with a hammer. Punches shank end deforms after sometime and forms into a mushroom type structure which can be removed with the help of bench grinder. When working with punches we should we eye and face protection. There are 4 types of punches namely Center,Pin,Hollow,Drift.
CENTER PUNCH
Center punch is a relatively sharp pointed tool, which is used to make indentation for drill bits, center punch ground angle can be pointed at angles of 60-90 degrees which depends upon hardness of the metal. Another form of center puch is the dot or prick which is used to make indentations along a line which is hard to see. Center punches should not be used to take out pins or rivets from holes.
PIN PUNCHES
Pin punches are used to remove pins and rivets from their respective holes the driving end of the rivet should be cut flat whereas its ground angle depends upon the pin/rivit inside the hole. Pin punches usually have parallel or tapered driving ends.
HOLLOW PUNCHES
Hollow punches are used to make holes for bolts in thin sheets and gasket material, which is difficult to cut with a drill machine, the material being cut should be supported by a wooden block to avoid damaging the hollow punch.
DRIFTS
Drifts are made from aluminium alloy, copper or steel bars and are used to drive out bushes, bearings, shafts from their respective cages. Only steel drifts should be used to drive out bearings from its respective case.
Punches are useful for maintaining and making of different stuff and for working kn metal sheets.
Punches are used to Concentrate the force Deliver by the hammer On One Point of the Punch Tip. The force delivered by the hammer with a puch is greater then the force delivered by hammer with puch.
ReplyDeleteTypes Of Punches:
Center Punch: Used to make Indentation on Metal of A drill bit to start Drilling. The angle of the puch point is between 60° to 90° But it depends on the hardness of metal. The softer the metal the larger will be the angle of punch point
The two other types of puches are "Dot" or "Prich" used for marking and indentation on Drawn line as a witness point to insure that the Cutting line is Correct.
CENTER PINCH SHOULD NOT BE USED FOR DRIVING OUT PINS AND RIVITS FROM THEIR RESPECTIVE HOLES.
Pin Punches: Used for driving out Pins and Rivits from their holes the Driving end of the puch is cut flat and Diameter Ground to match with that of Rivits and pins being driven from its holes
Hollow Punches: Used for Punching out Holes for bolts on Soft Thin sheets like shimmers and Gaskets materials which are Difficult to drill. The material to be punched should be supported by a Wooden block to avoid the Punch point of the hollow punch from damaged
Drifts: Used for driving out Bearing, Bunches and Shafts from their respective housings and cages.
Only steel metal should be used to avoid the possibility of flying chips from the soft metal breaking and Causing damage.
Aimal Khan
There are more commonly found in an engineer's toolkit including centre punch, pin punch, hollow punch,
ReplyDeleteDrift.
Centre Punches are relatively sharp pointed tools, used to
make an indentation in metal.
Pin puches is cut flat amd using for remove pins and revits.
Hollow punch are use to punch out bolt hole in soft.
Inam
DeleteIn Aviation punches are tools used in conjunction with gamers to concentrate force at a specific area.
ReplyDeleteFirst three punches are made of cast steel and their length can vary from 127 mm ( 5 inch ) to 3.175 mm ( 0.125 inch ).
Center punches are sharp pointed and are used to to mark center point prior to drilling operation. They should be struck hard enough to cause an indent but not hard enough to cause distortion of metal. There is an other type of Center punch called dot or prick ( pricker ) which is used to mark indentation on a drawn line which is not visible enough. These indentations can also be used as a reference when cutting to make sure the cutting operations has been carried out properly. Center punches should not be used to remove rivets or pins from a hole.
Pin punches are used to remove rivets or pins from their holes. The driving end is cut flat and grounded to match the diameter of the rivet or pins that are to be removed from their holes. The driving end can be parallel or tapered.
Hollow punches are used to make bolt holes in a soft metal sheet such as shimmers or gaskets where hole can not be formed by a drill because of the area being confined.
Drifts are used to take out bushes, bearing and shafts out of their holes. They are usually made of aluminium alloy or copper or steel.
Proper results are obtained when correct tool is used and should not be subjected to rough use.
It is not a pounding tool they are used to concentrate the blow of hammer.
ReplyDeleteThere are four types of punches.
Centre punches: they are relatively sharp pointed tools, used to make an indentation in metal. The softer the metal the larger the angle. Another form is dot or prick punch which are used to make indentation along a drawn line.
Pin punches: they are used to remove pins and rivets from their respective holes.
Hollow punch: they are used to punch out bolt holes in soft, thin sheets such as shimming or gasket materials which are difficult to cut with drills.
Drifts: they are made of aluminium alloy, copper or steel. They are used for driving out bearing, bushes or shafts from their places.
Only steel bearing should be used on bearing due to possibility of small metal chips breaking off.