SalahGasim Ahmed MET MET 103 Dr. Salah Gasim Ahmed ACX F 92

2 Drilling machines

SalahGasim Ahmed MET Drilling machines, or drill presses, are used for:Drilling machines, or drill presses, are used for: making holes and other operations.making holes and other operations. They are available in a wide variety of types and sizes.They are available in a wide variety of types and sizes. The most common types are:The most common types are: 1.Sensitive drill press 2.Upright drilling machines 3.Multiple spindle head drilling machine: 4.The radial drilling machine 5.Gang drilling machine Drilling machines, or drill presses

Bench Mounted Sensitive drill press SalahGasim Ahmed MET Floor Mounted Sensitive drill press

5 1-Sensitive drill press 1.Bench type 1.Floor type They are designed for drilling holes up to ½ inch Drilling head Table Column Base press bench type Spindle press floor type

SalahGasim Ahmed MET Upright drilling machines  Upright drilling machine is similar in design to the sensitive drill press but it has the following advantages: –It is larger and stronger than the sensitive type –It is used for drilling large hole –It has a gear drive mechanism to change the spindle speed –It may have a mechanical device to raise the work table

SalahGasim Ahmed MET Floor Mounted Sensitive drill press Up right drill press

Drive System 8 stepped-vee pulley and belt variable-speed drive

SalahGasim Ahmed MET The radial drilling machine Drilling head Spindle Table Base Column Radial arm

SalahGasim Ahmed MET The radial drilling machine  The radial drilling machine is sometimes called the radial arm press. It has the following advantages It is used for large work It is used for large work Several holes can be drilled without moving the work piece Several holes can be drilled without moving the work piece It can accommodate various height of work It can accommodate various height of work The machine has more power, thus larger cutting tool can be used. The machine has more power, thus larger cutting tool can be used. On some models the drilling head can be swiveled so that holes can be drilled at an angle On some models the drilling head can be swiveled so that holes can be drilled at an angle

SalahGasim Ahmed MET Gang drilling machine  It is basically a series of single spindle drill presses mounted on a long table  It is used for mass production  It performs different drilling operations in sequence  The work is moved along the table from a station to the next  It eliminates the need for changing cutting tools

SalahGasim Ahmed MET Multiple spindle head drilling machine  It is equipped with two or more heads  Each head has several spindles  It is used for production work only

SalahGasim Ahmed MET

SalahGasim Ahmed MET

Machine Capacity  Machine capacity is measured by the diameter of work that can be drilled.

SalahGasim Ahmed MET Spotting and Center Drills Spotting drills are used to position holes accurately for drilling with regular drills. Lathe center drills are often used as spotting drills.Lathe center drills are often used as spotting drills.

SalahGasim Ahmed MET Twist drills A twist drill is an end cutting tool used to produce a hole in a piece of metal or other material. BodyPointShank Flute Clearance Margin The main parts of a twist drill Straight shank : up to ½ inch Taper shank : more than ½ inch

Cutter holding device SalahGasim Ahmed MET For straight shank: Drilling chuck Drilling chuck For Taper shank: Sindle Sindle Sleeves Sleeves

SalahGasim Ahmed MET Drill point angles : For general purpose drilling Drill point angle = For hard materials: Drill point angle = For soft materials: Drill point angle = 90 0

SalahGasim Ahmed MET

SalahGasim Ahmed MET

SalahGasim Ahmed MET

SalahGasim Ahmed MET Measuring the size of a twist drill:  It is a good practice to always check a drill for size before drilling a hole. Drill may be checked for size by two methods: –A drill gauge: –A micrometer or vernier:  Always be sure that the measurement is taken across the margin of the drill.

SalahGasim Ahmed MET Selection of the proper speeds:  Factors which affect the cutting speed are: –Kind of work piece material –Kind of cutting tool material –Use of cutting fluid –Size and type of drilling machine –Quality of finish

SalahGasim Ahmed MET Calculation of cutting rpm  The required rpm can be obtained from the equation:  Metric  Where, –CS : cutting speed (m/min), from table (1) –d : diameter of twist drill (mm)  Inch  Where, –CS : cutting speed (ft/min), from table (1) –d : diameter of twist drill (in)

SalahGasim Ahmed MET Table (1) Cutting Speeds for High Speed Steel Drills Table (1) Cutting Speeds for High Speed Steel Drills MaterialMeter/minFoot//min Low carbon steel 0.05 – 0.3 % carbon – – 110 Medium carbon steel 0.3 – 0.6% carbon21.4 – – 80 High carbon steel 0.6 – 1.7% carbon ….15.2 – – 60 Steel forgings ………………………….15.2 – – 60 Alloy steel …………………………… – – 70 Stainless steel ………………………….9.1 – – 40 Cast iron, soft gray …………………….30.5 – – 150 Cast iron, hard chilled ………………… 21.4 – – 100 Cast iron, malleable …………………… 24.4 – – 90 Ordinary brass & bronze ……………… 61.0 – – 300 High-tensile bronze …………………… 21.4 – – 150 Monel metal ………………………… – – 50 Aluminium and its alloys …………… – – 300 Magnesium and its alloys …………… – – 400 Slate marble & stone …………………..4.6 – – 25 Bakelite and similar plastics ………… – – 150 Wood ………………………………….91.4 – – 400

SalahGasim Ahmed MET Twist drill materials  Carbon tool steel  High speed steel  Cemented carbide

SalahGasim Ahmed MET Type of twist drills: General purpose drill: It suits a wide variety of materialsIt suits a wide variety of materials Low helix drill: It is used for soft materials: aluminium, brass, magnesium etc, for shallow holesIt is used for soft materials: aluminium, brass, magnesium etc, for shallow holes High helix drill: It is used for deep holes It is used for deep holes It is used for : aluminium, copper, die cast materials, plasticsIt is used for : aluminium, copper, die cast materials, plastics Core drill: For drilling punched and cored holesFor drilling punched and cored holes Coolant ole drill (oil hole drill) It has two holes from the shank to the cutting point It has two holes from the shank to the cutting point It used in production machines It used in production machines Straight flute drills: for drilling brass, sheet metal work and non-ferrous materials for drilling brass, sheet metal work and non-ferrous materials

SalahGasim Ahmed MET Safety rules  Wear safety glasses or goggles  Never leave the chuck key in a drill chuck at any time  Never leave the drill drift in spindle  Mount work securely, do not hold thin or small work pieces in hands while drilling  Do not attempt to stop the spindle by the hands  Keep long sleeves away from spindles  Long hair could be very dangerous when drilling  Keep work area and floor clean and free from oil and grease

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