BENCH pptx Lecture Rommel

8/6/2019 BENCH pptx Lecture Rommel

http://slidepdf.com/reader/full/bench-pptx-lecture-rommel 1/59

BENCH WORK



BENCH WORK

- the ability of using different hand

tools such as files, hack saw, hammer, screwdriver, drift punch, center punch, chisels,scraper, laying out tools and final fitting of

parts.



SAFETY ON BENCH WORK

- most accidents to bench workers are

caused by thoughtless use of tools whichincludes using a tool incorrectly or carelessly.Many accidents result from using a tool to do

something for which it was not intended.



FILES

1. Be sure that the file has a handle. See that thehandle fits securely. Never use a file without handle.

2. Remove burst and abrasion from the file handlebefore using it. They caused blisters.

3.Striking file with a hammer will also caused steelsplinters to fly.

4. Do not used files as a hammer. Flying pieces of hardened steel can pierce human skill.5. Using a file as a pry bar is a sure way of breaking it.

6. Keep file teeth clean of pins. Do not let oil and dirtcollect on the gullets of the file.



HAMMERS

1.Always check the fit of the handle in thehammer head.

2. Do not used a hammer with a broken or splithandle.

3.Always remove oil, grease and dirt from theface and the handle of the hammer.

4. Never use the face of the hammer to strikeagainst another hardened tool.

5. Use the right size hammer for the job.



WRENCHES

1. Keep wrenches clean, wipe off oil and grease before using thewrenches.

2.Stop any machine before using a wrench whether it is tootighten, loosen, remove or adjust, first stop the machine.

3. Be sure that the wrench fits the nuts snugly. An oversizewrench will slip and round off the corners of the nut.

4. Whenever possible, pull on the wrench, dont push.

5.Stand with proper balance whenever it is necessary to pull hardon a wrench one leg behind the other.

6. The design of the wrench provides a sufficient length for safeleverage.



HACKSAW

1. Grip the work in the vise so that the saw cut will be near

the jaws.2.Apply pressure only on the forward stroke.

3.Start the saw cut with a light, even forward strokeholding the saw frame at an angle. When the cut isestablished, hold the frame level and saw the full width of the job.

4.Take the longest stroke possible but do not permit theblade supporting pins to touch the job.

5. Used blade having the proper number of teeth per inch tosuit the job fine pitch for thin metal, coarse piece for thickpieces.



DRILL PRESS AND DRILLINGS

1. Think about what you are doing. Keep your mind on the job.

2. Dress safely. Remove rings, watches, identification bracelets andneckties. Roll up the sleeves.

3. Fasten the job or vise securely to the table.4. Remove tools, clamps, wrenches and so forth from the table beforestarting the drill.

5. Remove drill drift from the spindle or chuck key from the drill chuckimmediately after used.

6. When the drill become dull, re sharpen or replace it.

7. Grind the drill correctly for the metal it is required to cut.

8.As the drill breaks through the work, relieve the down feed pressure.

9.Stop the machine before measuring or adjusting the job.

10.Stop the machine before using a brush to remove chips and excesscoolant.



GENERAL SHOP SAFETY



CLOTHING no necklace, wristwatch, jewelries and only short

sleeves are advisable.

Should have apron shop coat or coveralls

Dont use woolen sweater ( long and unbrokenstrands)

Using canvass shoes (snickers)

When to use gloves (when moving pieces of stockwith sharp edges)

The importance of goggles.



SHOP WORK

feet 8 to 12 inches apart and good balance

bend knees to distribute the load when carrying tothe person who would help you lift a load to haveaccurate movements.

Carrying long steel bars should be on the shoulder,

it should be vertical Dont leave pieces of stock on the floor

Grease on the floor isnt safe.



A machinist must be skilled in the use of the

numerous hand tools which have been

designed to make his work easier.In addition,knowing how to used hand tools properly, the

machinist must also know the various types

of tools available to do a particular job and

how to care for and store the tools correctly.



HAMMERS

Hammers were one of the mans earliest

tools. The types of hammer used by somemachinist are limited but they are available inmany sizes. Machinist hammer are classified

as hard or soft hammer.



A hard hammer is one that is made of carbon

steel and forged to size and shape. It is heat

treated to make the striking faces hard.A soft hammer may have the entire head made

of a soft metal such as lead, copper or brass.

A soft-face hammer have only their strikingsurfaces made of plastic, rubber or rawhide.

The faces are either clamped or press fitted

on the metal hammerhead.



USES OF HARD HAMMER

For st r iking:

Punches c. steel letters cold chisels d. figures

Hammer is also used for :

forging hot metal d.straightening

riveting e. pining

bending f. stretching

and swaging



THE MOST COMMONLY USED HAMMER BY

SOME MACHINIST

1. Soft hammer with brass head



2. Plastic-faced Soft hammer



3. Ball-peen hammer and its part



4.Straight peen hammer



5. Cross-peen hammer and its part



The sized of the hammer is specified by

the weight of the head without the handle.

Ball-peen hammer sizes ranged from 2onz to3lb.

Size of the soft face hammers are

specified by the diameter of the face and the

length of head and range from 5/8 inchdiameter o 3 inches diameter. Faces arespecified in degrees of hardness from super

set to extra hard





hand punch

is a tool held by hand against the work

piece. The end in contact with work piece isshaped to do a particular job whereas theother end is flat so that it could be struck

easily by the hammer. Punches come in many

sizes and shapes to do a variety of jobs.



TYPESOF PUNC HES

Drift punch

Drive pin punch Prick punch

Center punch

Automatic center punch



drift punch is a long tapered punch used for

loosening straight pins, tapered pins, rivets

and other small parts being assembled.



Drive pin punches

are used to set in place or remove straight

and taper pins and some types of small partsrequiring a drive fit. The diameter of thepunch ends are made slightly smaller than

the nominal size so that the punch will not

blind in the hole.



prick punch

is made of hardened tool steel and ground toa slender point having 30 degrees to 60 degrees

included angle. It is used to mark slightly orindent the intersections of layout lines to locate

hole centers and to provide small center markfor divider points when laying out circles or

spacing dimensions



center punch

is similar to prick punch in appearance except

for the point which ground to 90 degreesincluded angle. The center punch is used to

enlarge a prick punch mark so a drill can be

started in the exact location.A

center punchmark is deeper and larger than prick punch

mark.



automatic center punch

makes punch marks of a uniform sizeswithout the used of hammer. The knurled cap

may be turned to control the depth of the punchmark. It is necessary to locate the punch point

and push down.



Screwdriver

is a hand tool that is designed to turn

screws. The shank is made of steel set into awooden or plastic handle. The blade is shaped

or flattened to fit recesses in the heads of the

screws or bolts. Screwdrivers are made in

many sizes.



TYPES OF SCREWDRIVERS

� stubby screwdriver

�

heavy duty screwdriver� Philip screw driver

� Jewelers screwdriver

� Plain screwdriver

�

Double ended offset screwdriver



stubby screwdriver

helps to start screw where the space is

limited.



heavy d uty scr ewd r iver

is of average length but is made with a heavyblade and square shank. The shape of the shank

permits the use of the wrench to assist in

tightening a screw. Heavy material is used so

that the blade and shank will resist being twistedwhen a wrench is used.



phili p scr ewd r iver

is specially designed to fit the heads of

philip screws. It differs from otherscrewdrivers in that the end of the blade isfluted instead of flattened. It is made in

several sizes.



A j eweler s set of scr ewd r iver

is designed for loosening very small

screws, and it is use only some screws of jewellerys.



d ouble-ended off set scr ewd r iver

is used for turning screws in awkward

place where there is not enough room to usea regular screwdriver.



plain scr ewd r iver

is that the shank is made of steel set into a

wooden or plastic handle. The blade is shaped or

flattened to fit recesses in the heads of screw or

bolts.It is made in a variety of sizes.



CLAMPING AND HOLDING DEVICES



C-CLAMP

AC-clamp is an all-purpose clamp, made inthe shape of letter C. In general use for all kinds

of work, it is made in many sizes.



BENCH VISE

A bench vise, usually swivel based is the

kind of most favored for general shop work. Itis securely fastened to the bench with bolts.The faces of the jaw are usually lightly

serrated are hardened to ensure a firm grip

on the work. Finished surfaces should beprotected when placed in the vise by usingbrass or copper jaw caps. Tightening the vise

by hammering on the handle is poor practice.



Bench Vise



WRENCHES

A wrench is a tool for turning nuts and

bolts. It is usually made of steel. There aremany kinds of wrenches. They may consist of a slot, socket, pins, or movable jaws for

grasping the nut, with the rest of the tool

serving as a handle for applying pressure.



TYPESOF WRENCHES

Single-ended wrenches

Double ended wrenches

Close end wrench

Adjustable wrench Lever-jaw wrench

Combination wrench

Check-nut wrench

Tool post wrench

Square box wrench

T-handle tap wrench

Adjustable tap wrench

12 point box wrench

T-socket wrench

Offset socket wrench

Pinhook spanner wrench

Adjustable-hook spannerwrench

Pipe wrench

Allen wrench Socket wrench

Torque wrench



A single-ended wrench is one that is made to fit

the size of nut and bolt.



A double-ended wrench has two openings, one

at each end of the handle, to fit two different

sizes of nuts and bolt heads



A close-end wrench is similar to single-ended

wrench, but because it entirely encloses a

nut, there is a little danger of the wrenchslipping on the nut or of the jaws spreading

apart.



A check-nut wrench is a thin, single ended or

double ended wrench used for turning checks

or jam nut.



A tool post wrench is a combination box

wrench and open end wrench. The open-end

is straight rather than offset. The square boxend is designed to fit tool post screws and set

screw on the lathes and machine tools.



A square box wrench is a single head close-end

wrench having a rather short handle. It is

widely used for square head screws.



A T -handle tap wrench is used to hold and turn

small taps up to about ½ inch. It usually has

two inserted jaws, which can be adjusted tofit the square end of the tap.



An adjustable tap wrench is a straight type of wrench having a solid V-shaped opening at the

centre.A sliding member, or adjustable jaw,operated by one of the handles makes it possible

to hold taps of various sizes.



A T -socket wrench made in the form of T. The

hole or socket, in the end is made in variety of

shapes such as square, hexagonal, oroctagonal.



An offset socket wrench is made of some

variety of sockets as T-socket wrench. It is

designed to be used on nuts requiring greatleverage.



A pinhook spanner wrench is designed to fit

around the edge of the large round nuts,

which have holes in them to fit the pins of thewrenc



A pipe wrench is designed with adjustable jaws

that are serrated, making it possible to grip

round pipe and other cylindrical parts.



An allen wrench is made of hexagonal shaped

stock to fit the holes in the head of set screws

or socket head screws.



T orque wrenches are used when it is necessary

to know the amount of turning or twisting

force being applied to a nut. The amount of force is usually indicated on dial scale, which

is mounted on the bench handle.



An adjustable wrench has a movable jaw,

which makes it adjustable to various sizes of

nuts. When using this type of tool, point the jaw in the direction of force applied.



Date post:	07-Apr-2018
Category:	Documents
Upload:	christian-de-la-cruz
View:	225 times
Download:	0 times

BENCH pptx Lecture Rommel

Documents