7.3.7 Marking Out Flashcards
What materials are rules made of?
Rules are made of tempered carbon steel or satin-finished stainless steel.
What are the standard lengths of rules?
Rules usually come in standard lengths of six inches (152.4 mm) and 12 inches (304.8 mm).
What unit of measure is most used in aviation?
The unit of measure most used in aviation is the ‘inch’.
What scales do most rules have?
Most rules have a graduated scale in both the fraction and metric system.
What is a rule used for?
A rule can be used either as a measuring tool or as a straight edge.
How are fractional scale divisions for an inch determined?
The fractional scale divisions for an inch are found by dividing the inch into equal parts.
What are the fractional divisions of an inch?
Halves (1/2), Quarters (1/4), Eighths (1/8), Sixteenths (1/16), Thirty-seconds (1/32), Sixty-fourths (1/64).
How can fractions of an inch be expressed?
Fractions of an inch can be expressed in decimals, called decimal equivalents of an inch.
What is a flexible steel tape used for?
The flexible steel tape is a very useful instrument for taking measurements up to several feet.
What feature does a flexible steel tape have?
The steel tape is equipped with a hook on one end to hold onto a corner or ledge.
What is the purpose of the hook on a steel tape?
The hook allows the rule to be used by one individual and accounts for its thickness in calculations.
What measurements do most steel tapes have?
Most steel tapes have a graduated scale in imperial and metric measurements.
What is the role of a steel rule and tape measure in an Aircraft Engineer’s toolkit?
They are used as a guide and are not subject to calibration.
When must a ruler be calibrated?
If a ruler is being used to accurately measure an item for inspection or modification, then a calibrated one must be used.
What is a combination set used for?
The combination set can be used for the same purposes as an ordinary tri-square.
What features does a combination set have?
It has a sliding head, a level, and a scriber.
What is the purpose of the spirit level in the square head of a combination set?
It makes it convenient to square a piece of material and check if it is plumb or level.
What can the combination of square head and rule be used for?
It can be used as a marking gauge, to scribe lines at a 45° angle, as a depth gauge, or as a height gauge.
What is the Engineers Square used for?
It is used for marking out on metal.
What are common sizes of Engineers Squares?
Common sizes usually available range from 3” to 12”.
What standards do Engineer Squares conform to?
They conform to UK and European Standard, BS 939 and DIN 875 respectively.
What is the purpose of a scriber?
The scriber is used to scribe or mark lines on metal surfaces.
What are the characteristics of a scriber?
The scriber is made of tool steel, 10 to 100 cm long, with two needle pointed ends.
What is the use of dividers?
Dividers are used for scribing arcs and circles, measuring between points, and transferring dimensions.
What are the two common types of callipers?
Inside and Outside callipers.
What are radius gauges used for?
Radius gauges are used to measure either the inside or the outside radii.
What is a feeler gauge set made of?
Feeler gauge sets are made up of several thin steel leaves that fold into a handle.
What technique is practiced with a feeler gauge?
The ‘Go, No-Go’ technique.
What are punches classified by?
Punches are classified according to their shape of head.
What is a prick punch used for?
A prick punch is used when marking up a piece of metal to show where holes are to be drilled.
What is a centre punch used for?
A centre punch is used to make indentations in metal to prevent ‘wander’ when starting to drill a hole.
What is an automatic centre punch?
An automatic centre punch incorporates an adjustable spring-loaded trip mechanism.
What is the purpose of a starting (taper) punch?
It is used to start when driving out a bolt or pin.
What are pin punches used for?
Pin punches are used for driving out rivets and are sized by the diameter of the face.
What is a roll pin punch used for?
Roll pin punches are used for the removal of roll pins.
What materials can be used for punches to minimize damage?
Beryllium-Copper and Brass Punches are used where damage may occur.
What maintenance is required for punches?
The punch end must be ground back to its original shape if it becomes burred.
