c7.3

36問 • 1年前

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In files the grade indicates the

degree of coarseness of the teeth

Single cut files are used for cutting hard metals, they have an unbroken series of cuts, parallel with each other but running at

an angle of 60-80° to the length of the file

Flat Chisel

•65° is for tool steel •50° is for mild steel •30° is for aluminum

Cross-cut chisel The cutting edge varies in width

from 1⁄8” to 3⁄8”

The chisel is reduced in width behind the cutting edge to

give clearance when cutting grooves

The chisel is forged down to width to give strength to the cutting edge

The point angle varies from 65° for steel to 30° for aluminum

the Consideration for selecting correct chisel for the job must be given

to both the nature of the work and to the material that is to be cut

The choice of blade for a hacksaw is for

soft metal require coarse blades and hard metal require fine blade

The choice of teeth per inch (TPI) of a hacksaw is governed

by the shape and thickness of the material to be cut

At least three teeth

must be in contact with the material at any given time

Piercing saws

are similar in general shape but the frames are deeper and sometimes adjustable for length. Serrated and hardened clamps ensure a firm grip on the blades, which are 5" long with TPI from 32 to 80

A flange spanner is a ring spanner with

very thin walls and a small crank

C’ spanner and adjustable ‘C’ spanner This form of spanner is for use on

slotted circular nuts and collars and is available in set sizes or a range of adjustable sizes.

One of scraper in general use is flat type is used

for producing accurate flat surface :

Tri-wing Some airlines use screws with a special screw head produced by the Phillips Screw Company.

These screws have three slots instead of the four slots found on the regular cross-point screw.

What is difference between Gauging and measuring instruments ?

Gauging differs from measuring in that measuring instruments are used to give a direct numerical value to a dimension whilst gauges are used to compare a dimension to a known

Ring gauges check for

dimension, roundness and taper

If ring gauges used in Go no Go situation

Two ring gauge must be used

Micrometers used to take accurate imperia or metric measurement. Used when additional accuracy is required It

reads 0.0001” or 0.002mm by the addition of Vernier scale on the barrel.

Always check

the zero reading of the micrometer before used

Countersink drills

Are used to set flush countersink screws and for countersinking prior to riveting. They are made with an included angle of between 60° and 120° depending on the head angle of the fastener to be installed

A power nibbler is a tool used for rough cutting small-to-medium sized holes in skins

It is hand held and has a reciprocating cutter

When cutting an internal and a mating external thread the

internal thread should be cut first

Ball Pein

primarily for riveting-type operations

Planishing hammer

Used for finishing beaten work

Bossing mallet

Used for shaping internal curves in sheet metal

Starting punches are

typically used to aid in driving bolts and pins from their holes

A Vernier Calliper is a versatile precision instrument, used to:

measure inside and outside dimensions and depth

a Vernier calliper ensure accurate readings :

( 0.02 mm accuracy ).

The main scale of a metric vernier caliper is:

calibrated in millimeter and half millimeter

The sine bar is used to :

produce angles using slip gauges.

Imperial unit uses:

fractions of an inch .

Selection and use of pliers and cutters based on:

1- the task to be performed 2- position and access requirement.

Drill gauges used for

checking the diameter drills, reamers, and rods.

The head of combination set is used to find the centres of circular bars is called

Center head

The main head of combination set has one edge at 90° and the other at 45° to the rule. this head is called

Square head

mod 4 test

Aljuboory · 81問 · 1年前

mod 4 test