Layout

Question 1

What are the two types of layout tables?

Answer 1

Cast iron surface plate

Granite surface plate (most common)

Both act as a reference or datum for inspection and layout procedures

Question 2

What are the three grades of surface plates?

Answer 2

Grade AA- laboratory grade is specified for precision operations in constant temperature gauging rooms.

Grade A- Inspection Grade is used for general work in quality control.

Grade B - tool room grade is used in production for checking work through out the shop

Question 3

What is used to mark metal for layout?

Answer 3

Scribers

Three main types:
Pocket
Double end
Knife edge (used for accuracy)

Question 4

What are dividers and trammels used for?

Answer 4

Scribing arcs and circles, and for transferring measurements.
Trammels scribe arcs and circles beyond the size capabilities of of dividers

Question 5

What are the two types of squares?

What are the components?

Answer 5

Solid square

Combination square

Beam

Blade

Question 6

What comes in the combination set square?

What are the uses?

Answer 6

Square head- check layout angles of 90 degrees and 45 degrees

Steel rule - used in combination with other tools, guide for scribing

Bevel protractor - check layout from 0degree to 180degree

Centre head - used to locate centre of round, square, octagonal shafts.

Question 7

What is a surface gauge used for?

Answer 7

Scribe horizontal lines parallel to its base.

Accurate to the smallest increment of a rule 1/64 or .5mm

Question 8

What height tool is used for precision layout? What is its accuracy?

What are the 3 types and there accuracy’s

Answer 8

Height gauge

Dial height gauge - 0.001”

Electronic height gauge- .0005” or .01mm

Vernier height gauge - .001” or .02mm

Question 9

What are the angles of a centre punch?

Answer 9

90 degrees

Question 10

What are the angles of a prick punch?

Answer 10

30-60 degrees

Question 11

What is a parallel?

What is it used for?

Answer 11

A parallels are manufactured blocks of steel used to support the workpiece for: milling, grinding, drilling, layout, etc while maintaining a parallel distance from the reference surface.

Question 12

What tool is used to support round and square stock for layout?

Answer 12

V blocks

Question 13

What are straight edges used for?

Answer 13

Check surface for flatness and can be a guide for the scriber.

Question 14

What are the different layout coatings?

Answer 14

Layout die(blueing) - general purpose

Copper sulphate - Ferrous metals

Vermilion powder and shellac - aluminum and copper

Chalk - hot rolled steel and castings

Lime and alcohol- large sized castings and hot rolled steel.

Question 15

What is a datum edge and why is it important?

Answer 15

Datum edges are reference point on a work piece. Used to measure and mark from.

Datum edges are flat, straight and right angles from each other.

Question 16

What is incremental dimensioning?

Answer 16

Incremental dimensioning is when you use your datum edge to mark your first point but then measure of your marks for the next holes.

The system is to be used when accuracy is not super important. Accumulated error will add distance to your hole position.

Question 17

What is Absolute dimensioning?

Answer 17

Absolute dimensioning is where all subsequent holes are marked off your datum edge.

This system should be used if tolerance is held at +/- 1/64”

Question 18

What is temporary layout?

Answer 18

When a work piece has only been laid out with scribe lines.

Question 19

When is permanent layout achieved?

Answer 19

When the layout lines have been lightly prick punched.

Question 20

How can you tell on your plans if you need semi precision layout or precision layout?

Answer 20

Semi precision - plans will be in whole number or fractions.

Precision - plans will be in decimals with tolerances in the thousands of an inch or hundredths of a mm.

Question 21

Why are granite layout tables/surface plate advantageous over cast iron?

Answer 21

• has little internal stress
• non magnetic
• does not oxidize or corrode
• not affected by temperature change
• does not but
• may be used near grinding machines without abrasive particles imbedding the plate

Question 22

When layout has been done with only scribed lines it is considered ______ layout?
When layout is prick punched along the lines it is considered________ layout?

Answer 22

Temporary
Permanent

Question 23

Why must copper sulphate only be used on ferrous metals?

Answer 23

Because it can react with non ferrous metals

Question 24

Vermillion powder and shellac are good for marking softer materials because?

Answer 24

Treatment produces a surface where lines can be scribed without scratching the underlying material.